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Sample records for jupiter explains lack

  1. Jupiter's Gossamer Rings Explained.

    NASA Astrophysics Data System (ADS)

    Hamilton, D. P.

    2003-05-01

    Over the past several years, Galileo measurements and groundbased imaging have drastically improved our knowledge of Jupiter's faint ring system. We now recognize that the ring consists of four components: a main ring 7000km wide, whose inner edge blossoms into a vertically-extended halo, and a pair of more tenuous Gossamer rings, one associated with each of the small moons Thebe and Amalthea. When viewed edge on, the Gossamer rings appear as diaphanous disks whose thicknesses agree with the vertical excursions of the inclined satellites from the equatorial plane. In addition, the brightness of each Gossamer ring drops off sharply outside the satellite orbits. These correlations allowed Burns etal (1999, Science, 284, 1146) to argue convincingly that the satellites act as sources of the dusty ring material. In addition, since most material is seen inside the orbits of the source satellites, an inwardly-acting dissipative force such as Poynting-Robertson drag is implicated. The most serious problem with this simple and elegant picture is that it is unable to explain the existence of a faint swath of material that extends half a jovian radius outward from Thebe. A key constraint is that this material has the same thickness as the rest of the Thebe ring. In this work, we identify the mechanism responsible for the outward extension: it is a shadow resonance, first investigated by Horanyi and Burns (1991, JGR, 96, 19283). When a dust grain enters Jupiter's shadow, photoelectric processes shut down and the grain's electric charge becomes more negative. The electromagnetic forces associated with the varying charge cause periodic oscillations in the orbital eccentricity and semimajor axis as the orbital pericenter precesses. This results in a ring which spreads both inward and outward of its source satellite while preserving its vertical thickness - just as is observed for the Thebe ring. Predictions of the model are: i) gaps of micron-sized material interior to Thebe and

  2. Jumping Jupiter Can Explain Mercury’s Orbit

    NASA Astrophysics Data System (ADS)

    Roig, Fernando; Nesvorný, David; DeSouza, Sandro Ricardo

    2016-04-01

    The orbit of Mercury has large values of eccentricity and inclination that cannot be easily explained if this planet formed on a circular and coplanar orbit. Here, we study the evolution of Mercury’s orbit during the instability related to the migration of the giant planets in the framework of the jumping-Jupiter model. We found that some instability models are able to produce the correct values of Mercury’s eccentricity and inclination, provided that relativistic effects are included in the precession of Mercury’s perihelion. The orbital excitation is driven by the fast change of the normal oscillation modes of the system corresponding to the perihelion precession of Jupiter (for the eccentricity) and the nodal regression of Uranus (for the inclination).

  3. Jupiter

    NASA Astrophysics Data System (ADS)

    Bagenal, Fran; Dowling, Timothy E.; McKinnon, William B.

    2007-03-01

    Preface; 1. Introduction F. Bagenal, T. E. Dowling and W. B. McKinnon; 2. The origin of Jupiter J. I. Lunine, A. Corandini, D. Gautier, T. C. Owen and G. Wuchterl; 3. The interior of Jupiter T. Guillot, D. J. Stevenson, W. B. Hubbard and D. Saumon; 4. The composition of the atmosphere of Jupiter F. W. Taylor, S. K. Atreya, Th. Encrenaz, D. M. Hunten, P. G. J. Irwin and T. C. Owen; 5. Jovian clouds and haze R. A. West, K. H. Baines, A. J. Friedson, D. Banfield, B. Ragent and F. W. Taylor; 6. Dynamics of Jupiter's atmosphere A. P. Ingersoll, T. E. Dowling, P. J. Gierasch, G. S. Orton, P. L. Read, A. Sánchez-Lavega, A. P. Showman, A. A. Simon-Miller and A. R. Vasavada; 7. The stratosphere of Jupiter J. I. Moses, T. Fouchet, R. V. Yelle, A. J. Friedson, G. S. Orton, B. Bézard, P. Drossart, G. R. Gladstone, T. Kostiuk and T. A. Livengood; 8. Lessons from Shoemaker-Levy 9 about Jupiter and planetary impacts J. Harrington, I. de Pater, S. H. Brecht, D. Deming, V. Meadows, K. Zahnle and P. D. Nicholson; 9. Jupiter's thermosphere and ionosphere R. V. Yelle and S. Miller; 10. Jovian dust: streams, clouds and rings H. Krüger, M. Horányi, A. V. Krivov and A. L. Graps; 11. Jupiter's ring-moon system J. A. Burns, D. P. Simonelli, M. R. Showalter, D. P. Hamilton, C. C. Porco, H. Throop and L. W. Esposito; 12. Jupiter's outer satellites and trojans D. C. Jewitt, S. Sheppard and C. Porco; 13. Interior composition, structure and dynamics of the Galilean satellites G. Schubert, J. D. Anderson, T. Spohn and W. B. McKinnon; 14. The lithosphere and surface of Io A. S. McEwen, L. P. Keszthelyi, R. Lopes, P. M. Schenk and J. R. Spencer; 15. Geology of Europa R. Greeley, C. F. Chyba, J. W. Head III, T. B. McCord, W. B. McKinnon, R. T. Pappalardo and P. Figueredo; 16. Geology of Ganymede R. T. Pappalardo, G. C. Collins, J. W. Head III, P. Helfenstein, T. B. McCord, J. M. Moore, L. M. Procktor, P. M. Shenk and J. R. Spencer; 17. Callisto J. M. Moore, C. R. Chapman. E. B. Bierhaus, R

  4. CROWDING-OUT OF GIANTS BY DWARFS: AN ORIGIN FOR THE LACK OF COMPANION PLANETS IN HOT JUPITER SYSTEMS

    SciTech Connect

    Ogihara, Masahiro; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi

    2013-11-20

    We investigate the formation of close-in terrestrial planets from planetary embryos under the influence of a hot Jupiter (HJ) using gravitational N-body simulations that include gravitational interactions between the gas disk and the terrestrial planet (e.g., type I migration). Our simulations show that several terrestrial planets efficiently form outside the orbit of the HJ, making a chain of planets, and all of them gravitationally interact directly or indirectly with the HJ through resonance, which leads to inward migration of the HJ. We call this mechanism of induced migration of the HJ ''crowding-out''. The HJ is eventually lost through collision with the central star, and only several terrestrial planets remain. We also find that the efficiency of the crowding-out effect depends on the model parameters; for example, the heavier the disk is, the more efficient the crowding-out is. When planet formation occurs in a massive disk, the HJ can be lost to the central star and is never observed. On the other hand, for a less massive disk, the HJ and terrestrial planets can coexist; however, the companion planets may be below the detection limit of current observations. In both cases, systems with a HJ and terrestrial planets have little chance of detection. Therefore, our model naturally explains the lack of companion planets in HJ systems regardless of the disk mass. In effect, our model provides a theoretical prediction for future observations; additional planets can be discovered just outside the HJ, and their masses should generally be small.

  5. Close-in planets around giant stars. Lack of hot-Jupiters and prevalence of multiplanetary systems

    NASA Astrophysics Data System (ADS)

    Lillo-Box, J.; Barrado, D.; Correia, A. C. M.

    2016-05-01

    Extrasolar planets abound in almost any possible configuration. However, until five years ago, there was a lack of planets orbiting closer than 0.5 au to giant or subgiant stars. Since then, recent detections have started to populated this regime by confirming 13 planetary systems. We discuss the properties of these systems in terms of their formation and evolution off the main sequence. Interestingly, we find that 70.0 ± 6.6% of the planets in this regime are inner components of multiplanetary systems. This value is 4.2σ higher than for main-sequence hosts, which we find to be 42.4 ± 0.1%. The properties of the known planets seem to indicate that the closest-in planets (a< 0.06 au) to main-sequence stars are massive (i.e., hot Jupiters) and isolated and that they are subsequently engulfed by their host as it evolves to the red giant branch, leaving only the predominant population of multiplanetary systems in orbits 0.06 Jupiters.

  6. Can Sulfur Explain the Bimodal Color Distribution Observed in the Jupiter Trojans?

    NASA Astrophysics Data System (ADS)

    Blacksberg, Jordana; Mahjoub, Ahmed; Poston, Michael; Brown, Michael E.; Eiler, John; Ehlmann, Bethany; Hodyss, Robert; Hand, Kevin P.; Carlson, Robert W.; Wong, Ian

    2016-10-01

    We present a series of experiments aimed at exploring the hypothesis that the presence or absence of H2S ice on the surface of primitive icy bodies in the early solar system is responsible for the bimodal color distribution of the Jupiter Trojans.Central to our proposed hypothesis is a location-dependent sublimation of ices in the primordial trans-neptunian disk which would have divided objects according to whether they retained H2S on their surfaces for sufficient time to incorporate their constituents into irradiated organic crusts. The irradiated crusts of objects with and without H2S would have different chemistry and therefore different optical properties. Dynamical instability models of the early solar system (e.g. Morbidelli et al., 2005, Nesvorny et al., 2013) predict that Trojans, formed from this primordial population, were later emplaced inward to co-orbit with Jupiter during large-scale rearrangement events. According to our hypothesis, the Trojans today would show evidence of their primordial location with respect to the H2S sublimation line in the form of a bimodal distribution in surface chemistry, and thus color.We present laboratory spectroscopy experiments in support of this hypothesis. Numerous thin ice films composed of H2O, CH3OH, NH3, were produced both with and without H2S. Subsequent processing of these icy bodies was simulated using electron irradiation and heating. Visible reflectance spectra show significant reddening when H2S is present. Mid-infrared spectra confirm the formation of non-volatile sulfur-containing molecules in the products of H2S-containing ices. The infrared spectral properties of the organic residues remaining at room temperature show that sulfur significantly changes the chemistry of these irradiation-produced organics. These experiments suggest that the presence of specific sulfur-bearing chemical species may play an important role in the colors of both the KBOs and Trojans today. This testable hypothesis could feed

  7. Contamination cannot explain the lack of large-scale power in the cosmic microwave background radiation

    SciTech Connect

    Bunn, Emory F.; Bourdon, Austin

    2008-12-15

    Several anomalies appear to be present in the large-angle cosmic microwave background (CMB) anisotropy maps of the Wilkinson Microwave Anisotropy Probe. One of these is a lack of large-scale power. Because the data otherwise match standard models extremely well, it is natural to consider perturbations of the standard model as possible explanations. We show that, as long as the source of the perturbation is statistically independent of the source of the primary CMB anisotropy, no such model can explain this large-scale power deficit. On the contrary, any such perturbation always reduces the probability of obtaining any given low value of large-scale power. We rigorously prove this result when the lack of large-scale power is quantified with a quadratic statistic, such as the quadrupole moment. When a statistic based on the integrated square of the correlation function is used instead, we present strong numerical evidence in support of the result. The result applies to models in which the geometry of spacetime is perturbed (e.g., an ellipsoidal universe) as well as explanations involving local contaminants, undiagnosed foregrounds, or systematic errors. Because the large-scale power deficit is arguably the most significant of the observed anomalies, explanations that worsen this discrepancy should be regarded with great skepticism, even if they help in explaining other anomalies such as multipole alignments.

  8. Inherent directionality explains the lack of feedback loops in empirical networks.

    PubMed

    Domínguez-García, Virginia; Pigolotti, Simone; Muñoz, Miguel A

    2014-12-22

    We explore the hypothesis that the relative abundance of feedback loops in many empirical complex networks is severely reduced owing to the presence of an inherent global directionality. Aimed at quantifying this idea, we propose a simple probabilistic model in which a free parameter γ controls the degree of inherent directionality. Upon strengthening such directionality, the model predicts a drastic reduction in the fraction of loops which are also feedback loops. To test this prediction, we extensively enumerated loops and feedback loops in many empirical biological, ecological and socio-technological directed networks. We show that, in almost all cases, empirical networks have a much smaller fraction of feedback loops than network randomizations. Quite remarkably, this empirical finding is quantitatively reproduced, for all loop lengths, by our model by fitting its only parameter γ. Moreover, the fitted value of γ correlates quite well with another direct measurement of network directionality, performed by means of a novel algorithm. We conclude that the existence of an inherent network directionality provides a parsimonious quantitative explanation for the observed lack of feedback loops in empirical networks.

  9. Inherent directionality explains the lack of feedback loops in empirical networks

    PubMed Central

    Domínguez-García, Virginia; Pigolotti, Simone; Muñoz, Miguel A.

    2014-01-01

    We explore the hypothesis that the relative abundance of feedback loops in many empirical complex networks is severely reduced owing to the presence of an inherent global directionality. Aimed at quantifying this idea, we propose a simple probabilistic model in which a free parameter γ controls the degree of inherent directionality. Upon strengthening such directionality, the model predicts a drastic reduction in the fraction of loops which are also feedback loops. To test this prediction, we extensively enumerated loops and feedback loops in many empirical biological, ecological and socio-technological directed networks. We show that, in almost all cases, empirical networks have a much smaller fraction of feedback loops than network randomizations. Quite remarkably, this empirical finding is quantitatively reproduced, for all loop lengths, by our model by fitting its only parameter γ. Moreover, the fitted value of γ correlates quite well with another direct measurement of network directionality, performed by means of a novel algorithm. We conclude that the existence of an inherent network directionality provides a parsimonious quantitative explanation for the observed lack of feedback loops in empirical networks. PMID:25531727

  10. Verbal/social autopsy study helps explain the lack of decrease in neonatal mortality in Niger, 2007–2010

    PubMed Central

    Kalter, Henry D; Yaroh, Asma Gali; Maina, Abdou; Koffi, Alain K; Bensaïd, Khaled; Amouzou, Agbessi; Black, Robert E

    2016-01-01

    Background This study was one of a set of verbal/social autopsy (VASA) investigations undertaken by the WHO/UNICEF–supported Child Health Epidemiology Reference Group to estimate the causes and determinants of neonatal and child deaths in high priority countries. The study objective was to help explain the lack of decrease in neonatal mortality in Niger from 2007 to 2010, a period during which child mortality was decreasing. Methods VASA interviews were conducted of a random sample of 453 neonatal deaths identified by the 2010 Niger National Mortality Survey (NNMS). Causes of death were determined by expert algorithm analysis, and the prevalence of household, community and health system determinants were examined along the continuum of maternal and newborn care, the Pathway to Survival for newborn illnesses, and an extended pathway for maternal complications. The social autopsy findings were compared to available data for survivors from the same cohort collected by the NNMS and the 2012 Niger Demographic and Health Survey. Findings Severe neonatal infection and birth asphyxia were the leading causes of early neonatal death in the community and facilities. Death in the community after delayed careseeking for severe infection predominated during the late neonatal period. The levels of nearly all demographic, antenatal and delivery care factors were in the direction of risk for the VASA study decedents. They more often resided rurally (P < 0.001) and their mothers were less educated (P = 0.03) and gave birth when younger (P = 0.03) than survivors’ mothers. Their mothers also were less likely to receive quality antenatal care (P < 0.001), skilled attendance at birth (P = 0.03) or to deliver in an institution (P < 0.001). Nearly half suffered an obstetric complication, with more maternal infection (17.9% vs 0.2%), antepartum hemorrhage (12.5% vs 0.5%) and eclampsia/preeclampsia (9.5% vs 1.6%) than for all births in Niger. Their mothers also

  11. The optical transmission spectrum of the hot Jupiter HAT-P-32b: clouds explain the absence of broad spectral features?

    NASA Astrophysics Data System (ADS)

    Gibson, N. P.; Aigrain, S.; Barstow, J. K.; Evans, T. M.; Fletcher, L. N.; Irwin, P. G. J.

    2013-12-01

    We report Gemini-North Gemini Multi-Object Spectrograph observations of the inflated hot Jupiter HAT-P-32b during two primary transits. We simultaneously observed two comparison stars and used differential spectrophotometry to produce multiwavelength light curves. `White' light curves and 29 `spectral' light curves were extracted for each transit and analysed to refine the system parameters and produce transmission spectra from 520 to 930 nm in ≈14 nm bins. The light curves contain time-varying white noise as well as time-correlated noise, and we used a Gaussian process model to fit this complex noise model. Common mode corrections derived from the white light-curve fits were applied to the spectral light curves which significantly improved our precision, reaching typical uncertainties in the transit depth of ˜2 × 10-4, corresponding to about half a pressure scale height. The low-resolution transmission spectra are consistent with a featureless model, and we can confidently rule out broad features larger than about one scale height. The absence of Na/K wings or prominent TiO/VO features is most easily explained by grey absorption from clouds in the upper atmosphere, masking the spectral features. However, we cannot confidently rule out clear atmosphere models with low abundances (˜10-3 solar) of TiO, VO or even metal hydrides masking the Na and K wings. A smaller scale height or ionization could also contribute to muted spectral features, but alone are unable to account for the absence of features reported here.

  12. A lack of functional NK1 receptors explains most, but not all, abnormal behaviours of NK1R-/- mice1

    PubMed Central

    Porter, A J; Pillidge, K; Tsai, Y C; Dudley, J A; Hunt, S P; Peirson, S N; Brown, L A; Stanford, S C

    2015-01-01

    Mice lacking functional neurokinin-1 receptors (NK1R-/-) display abnormal behaviours seen in Attention Deficit Hyperactivity Disorder (hyperactivity, impulsivity and inattentiveness). These abnormalities were evident when comparing the behaviour of separate (inbred: ‘Hom’) wildtype and NK1R-/- mouse strains. Here, we investigated whether the inbreeding protocol could influence their phenotype by comparing the behaviour of these mice with that of wildtype (NK1R+/+) and NK1R-/- progeny of heterozygous parents (‘Het’, derived from the same inbred strains). First, we recorded the spontaneous motor activity of the two colonies/genotypes, over 7 days. This continuous monitoring also enabled us to investigate whether the diurnal rhythm in motor activity differs in the two colonies/genotypes. NK1R-/- mice from both colonies were hyperactive compared with their wildtypes and their diurnal rhythm was also disrupted. Next, we evaluated the performance of the four groups of mice in the 5-Choice Serial Reaction-Time Task (5-CSRTT). During training, NK1R-/- mice from both colonies expressed more impulsive and perseverative behaviour than their wildtypes. During testing, only NK1R-/- mice from the Hom colony were more impulsive than their wildtypes, but NK1R-/- mice from both colonies were more perseverative. There were no colony differences in inattentiveness. Moreover, a genotype difference in this measure depended on time of day. We conclude that the hyperactivity, perseveration and, possibly, inattentiveness of NK1R-/- mice is a direct consequence of a lack of functional NK1R. However, the greater impulsivity of NK1R-/- mice depended on an interaction between a functional deficit of NK1R and other (possibly environmental and/or epigenetic) factors. PMID:25558794

  13. Explaining linkages (and lack of) between riparian vegetation biodiversity and geomorphic complexity in restored streams of northern Sweden

    NASA Astrophysics Data System (ADS)

    Polvi, Lina; Maher Hasselquist, Eliza; Nilsson, Christer

    2014-05-01

    plots at three elevations above the low water stage (0, 40, and 80 cm) along five transects; additionally, we determined which species were present within the entire riparian zone (60 m long reach, up to 80 cm elevation). Three metrics of biodiversity were calculated on the plot level (richness, Shannon's diversity index, and evenness); only richness could be examined at the reach scale. There are significant relationships between riparian vegetation biodiversity and the overall complexity gradient at the medium elevation and, based on some metrics, at the low elevation. However, these relationships are not fully explanatory or always linear, explaining up to ~40% of the variability and often being logarithmic. We conclude that reach-scale restoration of increasing complexity in a catchment without significant land-use impacts can have positive effects on biodiversity. However, there are several limiting factors in addition to channel complexity that affect the recovery of riparian zones after restoration: the potential complexity of a reach based on large-scale controls, time since restoration—which is a disturbance in itself, buffer distance to timber harvesting, distance and connectivity to colonist sources, and upland species (e.g., spruce trees) that have managed to colonize when the riparian zone was separated from the channel.

  14. Jupiter Eruptions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This visible-light image is from NASA's Hubble Space Telescope taken on May 11, 2007. It shows the turbulent pattern generated by the two plumes on the upper left part of Jupiter.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vi gorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  15. Sharpening Up Jupiter

    NASA Astrophysics Data System (ADS)

    2008-10-01

    , MAD project manager Enrico Marchetti and Sébastien Tordo from the MAD team tracked two of Jupiter's largest moons, Europa and Io - one on each side of the planet - to provide a good correction across the full disc of the planet. "It was the most challenging observation we performed with MAD, because we had to track with high accuracy two moons moving at different speeds, while simultaneously chasing Jupiter," says Marchetti. With this unique series of images, the team found a major alteration in the brightness of the equatorial haze, which lies in a 16 000-kilometre wide belt over Jupiter's equator [2]. More sunlight reflecting off upper atmospheric haze means that the amount of haze has increased, or that it has moved up to higher altitudes. "The brightest portion had shifted south by more than 6000 kilometres," explains team member Mike Wong. This conclusion came after comparison with images taken in 2005 by Wong and colleague Imke de Pater using the Hubble Space Telescope. The Hubble images, taken at infrared wavelengths very close to those used for the VLT study, show more haze in the northern half of the bright Equatorial Zone, while the 2008 VLT images show a clear shift to the south. "The change we see in the haze could be related to big changes in cloud patterns associated with last year's planet-wide upheaval, but we need to look at more data to narrow down precisely when the changes occurred," declares Wong.

  16. Jupiter's ring

    NASA Technical Reports Server (NTRS)

    1979-01-01

    First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

  17. Jupiter's Temperatures

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is one of the highest resolution images ever recorded of Jupiter's temperature field. It was obtained by NASA's Galileo mission, with its Photopolarimeter-Radiometer (PPR) experiment, during the sixth of its 10 orbits around Jupiter to date. This map, shown in the lower panel, indicates the forces powering Jovian winds, and differentiates between areas of strongest upwelling and downwelling winds in the upper part of the atmosphere where winds are strong. The map is based on measurements from the PPR's 27-micron wavelength channel. A ground-based image from the NASA Infrared Telescope Facility, atop Mauna Kea, Hawaii, showing thermal emission from holes in clouds at 4.85 microns, is shown in the middle panel for reference, with the outline of the area covered by the PPR. The upper panel shows the area covered by the Galileo Solid State Imager (SSI) also during the sixth orbit.

    Galileo's observations of the atmosphere targeted specific Jovian features, including the Great Red Spot and similar, but smaller, 'storms

  18. Can social capital help explain enrolment (or lack thereof) in community-based health insurance? Results of an exploratory mixed methods study from Senegal.

    PubMed

    Mladovsky, Philipa; Soors, Werner; Ndiaye, Pascal; Ndiaye, Alfred; Criel, Bart

    2014-01-01

    CBHI has achieved low population coverage in West Africa and elsewhere. Studies which seek to explain this point to inequitable enrolment, adverse selection, lack of trust in scheme management and information and low quality of health care. Interventions to address these problems have been proposed yet enrolment rates remain low. This exploratory study proposes that an under-researched determinant of CBHI enrolment is social capital. Fieldwork comprising a household survey and qualitative interviews was conducted in Senegal in 2009. Levels of bonding and bridging social capital among 720 members and non-members of CBHI across three case study schemes are compared. The results of the logistic regression suggest that, controlling for age and gender, in all three case studies members were significantly more likely than non-members to be enrolled in another community association, to have borrowed money from sources other than friends and relatives and to report having control over all community decisions affecting daily life. In two case studies, having privileged social relationships was also positively correlated with enrolment. After controlling for additional socioeconomic and health variables, the results for borrowing money remained significant. Additionally, in two case studies, reporting having control over community decisions and believing that the community would cooperate in an emergency were significantly positively correlated with enrolment. The results suggest that CBHI members had greater bridging social capital which provided them with solidarity, risk pooling, financial protection and financial credit. Qualitative interviews with 109 individuals selected from the household survey confirm this interpretation. The results ostensibly suggest that CBHI schemes should build on bridging social capital to increase coverage, for example by enrolling households through community associations. However, this may be unadvisable from an equity perspective. It is

  19. Can social capital help explain enrolment (or lack thereof) in community-based health insurance? Results of an exploratory mixed methods study from Senegal.

    PubMed

    Mladovsky, Philipa; Soors, Werner; Ndiaye, Pascal; Ndiaye, Alfred; Criel, Bart

    2014-01-01

    CBHI has achieved low population coverage in West Africa and elsewhere. Studies which seek to explain this point to inequitable enrolment, adverse selection, lack of trust in scheme management and information and low quality of health care. Interventions to address these problems have been proposed yet enrolment rates remain low. This exploratory study proposes that an under-researched determinant of CBHI enrolment is social capital. Fieldwork comprising a household survey and qualitative interviews was conducted in Senegal in 2009. Levels of bonding and bridging social capital among 720 members and non-members of CBHI across three case study schemes are compared. The results of the logistic regression suggest that, controlling for age and gender, in all three case studies members were significantly more likely than non-members to be enrolled in another community association, to have borrowed money from sources other than friends and relatives and to report having control over all community decisions affecting daily life. In two case studies, having privileged social relationships was also positively correlated with enrolment. After controlling for additional socioeconomic and health variables, the results for borrowing money remained significant. Additionally, in two case studies, reporting having control over community decisions and believing that the community would cooperate in an emergency were significantly positively correlated with enrolment. The results suggest that CBHI members had greater bridging social capital which provided them with solidarity, risk pooling, financial protection and financial credit. Qualitative interviews with 109 individuals selected from the household survey confirm this interpretation. The results ostensibly suggest that CBHI schemes should build on bridging social capital to increase coverage, for example by enrolling households through community associations. However, this may be unadvisable from an equity perspective. It is

  20. UV Studies of Jupiter's Aerosols and Hydrocarbons

    NASA Technical Reports Server (NTRS)

    Pryor, Wayne

    2004-01-01

    This project funded research related to our involvement in the Galileo Ultraviolet Spectrometer experiment. Pryor was a Co-I on that experiment, which recently ended when Galileo crashed into Jupiter's atmosphere. It also funded related research on HST observations of Jupiter's atmosphere, and Cassini observations of Jupiter's atmosphere, and ground-based studies of Jupiter's atmosphere using the facilities of McDonald Observatory. Specific activities related to this grant include study of UV spectra returned by Galileo UVS and Cassini UVIS, development of simple models to explain these spectra, participation in archiving activities for these data sets, travel to conferences, and publication of scientific papers. Highlights of our Jupiter research efforts include: 1.) evidence for heavy hydrocarbons in Jupiter's atmosphere (from HST) (Clarke et al. poster), that may be the source of Jupiter's stratospheric aerosols, 2.) detection of auroral flares in Jupiter's atmosphere from Galileo (Pryor et al., 2001). 3.) establishing a connection between coronal mass ejections and auroral outbursts (Gurnett et al., 2002), and 4) establishing a connection between short-term variations in Jupiter's auroral emissions and radio emissions (Pryor et al. presented at AGU in 2002, paper in preparation).

  1. Magnetospheres: Jupiter, Satellite Interactions

    NASA Astrophysics Data System (ADS)

    Neubauer, F.; Murdin, P.

    2000-11-01

    Most of the satellites of Jupiter, notably the large Galilean satellites Io, Europa, Ganymede and Callisto (see JUPITER: SATELLITES), orbit deep inside the magnetosphere of Jupiter (see JUPITER: MAGNETOSPHERE) and are therefore immersed in the flow of magnetospheric plasma (made of a mixture of electrons and ions) and subjected to an interaction with the strong Jovian magnetic field. These intera...

  2. Are hot Neptunes partially evaporated hot Jupiters?

    NASA Astrophysics Data System (ADS)

    Boué, G.; Figueira, P.; Correia, A. C. M.; Santos, N. C.

    2011-10-01

    The detection of short period planets (hot Jupiters and their lower mass counterparts, hot Neptunes and super-Earths) still defies the models of planet formation and evolution. Several possibilities have been proposed to explain the nature and formation process of the lower mass population, including in situ formation, disk migration, planet-planet scattering and kozai evolution, and the evaporation of a higher mass hot Jupiter. Using dynamical models and the best estimates for evaporation velocities, we show that under reasonable (and observed) physical conditions, hot Jupiter evaporation may explain the observed population of hot Neptunes/super-Earths.

  3. Are Hot Neptunes Partialy Evaporated Hot Jupiters?

    NASA Astrophysics Data System (ADS)

    Santos, Nuno; Boue, G.; Figueira, P.; Correia, A.

    2011-09-01

    The detection of short period planets (hot Jupiters and their lower mass counterparts, hot neptunes and super-earths) still defies the models of planet formation and evolution. Several possibilities have been proposed to explain the nature and formation process of the lower mass population, including in situ formation, disk migration, planet-planet scattering and kozai evolution, and the evaporation of a higher mass hot Jupiter. Using dynamical models and the best estimates for evaporation velocities, we show that under reasonable (and observed) physical conditions, hot Jupiter evaporation can explain the observed population of hot Neptunes/super-Earths.

  4. Galileo's Telescopy and Jupiter's Tablet

    NASA Astrophysics Data System (ADS)

    Usher, P. D.

    2003-12-01

    A previous paper (BAAS 33:4, 1363, 2001) reported on the dramatic scene in Shakespeare's Cymbeline that features the descent of the deity Jupiter. The paper suggested that the four ghosts circling the sleeping Posthumus denote the four Galilean moons of Jupiter. The god Jupiter commands the ghosts to lay a tablet upon the prone Posthumus, but says that its value should not be overestimated. When Posthumus wakens he notices the tablet, which he calls a "book." Not only has the deity's "tablet" become the earthling's "book," but it appears that the book has covers which Posthumus evidently recognizes because without even opening the book he ascribes two further properties to it: rarity, and the very property that Jupiter had earlier attributed, viz. that one must not read too much into it. The mystery deepens when the Jovian gift undergoes a second metamorphosis, to "label." With the help of the OED, the potentially disparate terms "tablet," "book," and "label," may be explained by terms appropriate either to supernatural or worldly beings. "Tablet" may recognize the Mosaic artifact, whereas "book" and "label" are probably mundane references to Galileo's Sidereus Nuncius which appeared shortly before Cymbeline. The message of the Olympian god indicates therefore that the book is unique even as its contents have limited value. The first property celebrates the fact that Galileo's book is the first of its kind, and the second advises that all results except the discovery of Jupiter's moons have been reported earlier, in Hamlet.

  5. Explaining the Modality Effect in Multimedia Learning: Is It Due to a Lack of Temporal Contiguity with Written Text and Pictures?

    ERIC Educational Resources Information Center

    Schuler, Anne; Scheiter, Katharina; Rummer, Ralf; Gerjets, Peter

    2012-01-01

    The study examined whether the modality effect is caused by either high visuo-spatial load or a lack of temporal contiguity when processing written text and pictures. Students (N = 147) viewed pictures on the development of tornados, which were accompanied by either spoken or written explanations presented simultaneously with, before, or after the…

  6. Voyager 2 Jupiter encounter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A NASA News Release is presented which contains the following: (1) general release; (2) two views of Voyager 2 flight past Jupiter; (3) Voyager mission summary; (4) Voyager 1 science results; (5) Jupiter science objectives; (6) Jupiter the planet and its satellites; (7) Voyager experiments; (8) planet comparison; (9) a list of Voyager science investigators and (10) the Voyager team.

  7. Heating of Jupiter's upper atmosphere above the Great Red Spot.

    PubMed

    O'Donoghue, J; Moore, L; Stallard, T S; Melin, H

    2016-08-11

    The temperatures of giant-planet upper atmospheres at mid- to low latitudes are measured to be hundreds of degrees warmer than simulations based on solar heating alone can explain. Modelling studies that focus on additional sources of heating have been unable to resolve this major discrepancy. Equatorward transport of energy from the hot auroral regions was expected to heat the low latitudes, but models have demonstrated that auroral energy is trapped at high latitudes, a consequence of the strong Coriolis forces on rapidly rotating planets. Wave heating, driven from below, represents another potential source of upper-atmospheric heating, though initial calculations have proven inconclusive for Jupiter, largely owing to a lack of observational constraints on wave parameters. Here we report that the upper atmosphere above Jupiter's Great Red Spot--the largest storm in the Solar System--is hundreds of degrees hotter than anywhere else on the planet. This hotspot, by process of elimination, must be heated from below, and this detection is therefore strong evidence for coupling between Jupiter's lower and upper atmospheres, probably the result of upwardly propagating acoustic or gravity waves. PMID:27462811

  8. Heating of Jupiter's upper atmosphere above the Great Red Spot.

    PubMed

    O'Donoghue, J; Moore, L; Stallard, T S; Melin, H

    2016-08-11

    The temperatures of giant-planet upper atmospheres at mid- to low latitudes are measured to be hundreds of degrees warmer than simulations based on solar heating alone can explain. Modelling studies that focus on additional sources of heating have been unable to resolve this major discrepancy. Equatorward transport of energy from the hot auroral regions was expected to heat the low latitudes, but models have demonstrated that auroral energy is trapped at high latitudes, a consequence of the strong Coriolis forces on rapidly rotating planets. Wave heating, driven from below, represents another potential source of upper-atmospheric heating, though initial calculations have proven inconclusive for Jupiter, largely owing to a lack of observational constraints on wave parameters. Here we report that the upper atmosphere above Jupiter's Great Red Spot--the largest storm in the Solar System--is hundreds of degrees hotter than anywhere else on the planet. This hotspot, by process of elimination, must be heated from below, and this detection is therefore strong evidence for coupling between Jupiter's lower and upper atmospheres, probably the result of upwardly propagating acoustic or gravity waves.

  9. Ionosphere-Thermosphere Coupling in Jupiter's Low Latitudes

    NASA Astrophysics Data System (ADS)

    Stallard, T.; Melin, H.; Johnson, R.; O'Donoghue, J.; Moore, L.; Miller, S.; Tao, C.; Achilleos, N. A.; Smith, C.; Ray, L. C.; Yates, J. N.

    2015-12-01

    One of the leading problems in our understanding of Jupiter's atmosphere, known colloquially as the 'energy crisis', is that the upper atmosphere has global temperatures far in excess of that predicted by solar heating. Unlike the Earth, solar heating has only a small effect on the thermosphere, varying little in temperature with local time, and with equatorial neutrals co-rotating with the planet due to meridional advection. Within the auroral region, ionosphere-thermosphere coupling produces strong flows and results in huge Joule Heating from auroral currents. In this region, the temperature excess can be explained, but Jupiter's fast rotation means that Coriolis forces prevent energy in the poles from transferring equatorward, so there remains no explanation of why low latitudes are overheated by a factor of 3-5 over that predicted by solar heating alone.Despite this anomaly, although the past twenty years has seen a wealth of new data and results in Jupiter's auroral region, studies of the equatorial region have been somewhat limited. This lack of investigation comes partly from the apparent uniform nature of the equatorial region, and partly from the difficulty in observing this region. It is only in the past three years that observers begun to re-examine this region, revealing evidence of complex interactions between the thermosphere and ionosphere, including what appears to be thermospheric weather patterns at a fixed planetary longitudes, stable over two decades; perhaps caused by continuous flows from the auroral region. Here, we introduce our recent research, in order to compare and contrast what has been observed at Jupiter with the more well understood interactions between Earth's ionosphere and thermosphere. We hope that this will open a discussion between the communities that will improve our understanding of the underlying physical processes, as they occur at both planets.

  10. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets.

  11. The formation of Jupiter's faint rings

    PubMed

    Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

    1999-05-14

    Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets. PMID:10325220

  12. Polar Lightning on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Images taken by the New Horizons Long-Range Reconnaissance Imager (LORRI) of Jupiter's night side showed lightning strikes. Each 'strike' is probably the cumulative brightness of multiple strikes. This is the first lightning seen at high latitudes on Jupiter; it demonstrates that convection is not confined to lower latitudes, implying an internal driving heat source. Their power is consistent with previous lightning measurements at Jupiter's lower latitudes, equivalent to extremely bright terrestrial 'super bolts.'

  13. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  14. Jupiter System Observer

    NASA Technical Reports Server (NTRS)

    Senske, Dave; Kwok, Johnny

    2008-01-01

    This slide presentation reviews the proposed mission for the Jupiter System Observer. The presentation also includes overviews of the mission timeline, science goals, and spacecraftspecifications for the satellite.

  15. Jupiter Hot Spot Makes Trouble For Theory

    NASA Astrophysics Data System (ADS)

    2002-02-01

    A pulsating hot spot of X-rays has been discovered in the polar regions of Jupiter's upper atmosphere by NASA's Chandra X-ray Observatory. Previous theories cannot explain either the pulsations or the location of the hot spot, prompting scientists to search for a new process to produce Jupiter's X-rays. "The location of the X-ray hot spot effectively retires the existing explanation for Jupiter's X-ray emission, leaving us very unsure of its origin," said Randy Gladstone, of the Southwest Research Institute in San Antonio and lead author of a paper on the results in the Feb.28, 2002 issue of the journal Nature. "The source of ions that produce the X-rays must be a lot farther away from Jupiter than previously believed." Chandra observed Jupiter for 10 hours on Dec. 18, 2000, when NASA's Cassini spacecraft was flying by Jupiter on its way to Saturn. The X-ray observations revealed that most of the auroral X-rays come from a pulsating hot spot that appears at a fixed location near the north magnetic pole of Jupiter. Bright infrared and ultraviolet emissions have also been detected from this region in the past. The X-rays were observed to pulsate with a period of 45 minutes, similar to the period of high-latitude radio pulsations detected by NASA's Galileo and Cassini spacecraft. Jupiter X-ray/UV/Optical Composite Credit: X-ray: NASA/SWRI/R.Gladstone et al. UV: NASA/HST/J.Clarke et al. Optical: NASA/HST/R.Beebe et al. An aurora of X-ray light near Jupiter's polar regions had been detected by previous satellites. However, scientists were unable to determine the exact location of the X-rays. The accepted theory held that the X-rays were produced by energetic oxygen and sulfur ions that became excited as they ran into hydrogen and helium in Jupiter's atmosphere. Oxygen and sulfur ions (originally from Jupiter's moon Io) are energized while circulating around Jupiter's enormous magnetosphere. And, some - the purported X-ray producers - get dumped into Jupiter's atmosphere

  16. Warm Jupiters from Secular Planet–Planet Interactions

    NASA Astrophysics Data System (ADS)

    Petrovich, Cristobal; Tremaine, Scott

    2016-10-01

    Most warm Jupiters (gas-giant planets with 0.1 {{au}}≲ a≲ 1 au) have pericenter distances that are too large for significant orbital migration by tidal friction. We study the possibility that the warm Jupiters are undergoing secular eccentricity oscillations excited by an outer companion (a planet or star) in an eccentric and/or mutually inclined orbit. In this model, the warm Jupiters migrate periodically, in the high-eccentricity phase of the oscillation, but are typically observed at lower eccentricities. We show that in this model the steady-state eccentricity distribution of the warm Jupiters is approximately flat, which is consistent with the observed distribution if we restrict the sample to warm Jupiters with detected outer planetary companions. The eccentricity distribution of warm Jupiters without companions exhibits a peak at e≲ 0.2 that must be explained by a different formation mechanism. Based on a population synthesis study, we find that high-eccentricity migration excited by an outer planetary companion (1) can account for ∼ 20 % of the warm Jupiters and most of the warm Jupiters with e≳ 0.4; and (2) can produce most of the observed population of hot Jupiters, with a semimajor axis distribution that matches the observations, but fails to account adequately for ∼ 60 % of hot Jupiters with projected obliquities ≲ 20^\\circ . Thus ∼ 20 % of the warm Jupiters and ∼ 60 % of the hot Jupiters can be produced by high-eccentricity migration. We also provide predictions for the expected mutual inclinations and spin-orbit angles of the planetary systems with hot and warm Jupiters produced by high-eccentricity migration.

  17. Jupiter System Observer

    NASA Technical Reports Server (NTRS)

    Senske, Dave; Prockter, Louise

    2008-01-01

    This slide presentation reviews the scientific philosophy that is guiding the planning behind the Jupiter System Observer (JSO). The JSO would be a long-term platform for studying Jupiter and the complete Jovian system. The goal is to advance the understanding of the fundamental processes of planetary systems, their formation and evolution.

  18. Voyage to Jupiter.

    ERIC Educational Resources Information Center

    Morrison, David; Samz, Jane

    This publication illustrates the features of Jupiter and its family of satellites pictured by the Pioneer and the Voyager missions. Chapters included are: (1) "The Jovian System" (describing the history of astronomy); (2) "Pioneers to Jupiter" (outlining the Pioneer Mission); (3) "The Voyager Mission"; (4) "Science and Scientsts" (listing 11…

  19. New Horizons at Jupiter

    NASA Astrophysics Data System (ADS)

    Stern, S. Alan

    2007-12-01

    New Horizons is NASA's reconnaissance mission to explore the Pluto system and small Kuiper Belt Objects (KBOs). I will describe the mission's history, current status, and instrument suite. I will then describe the Jupiter gravity assist flyby New Horizons conducted in early-mid 2007. This flyby involved over 700 observations in the Jupiter system, and represents the only spacecraft encounter with Jupiter planned to occur between the demise of Galileo in 2003 and the arrival of Juno in 2016. I will focus on results obtained, including the first-ever exploration of a giant planet magnetotail, new compositional observations of icy Galilean satellites, exploration of Jupiter's tenuous ring system, the first high-resolution spacecraft imagery of Jupiter's newly-generated little red spot, and the first-ever time-lapse imagery of an Ionian volcano eruption.

  20. Jupiter's Hot, Mushy Moon

    NASA Technical Reports Server (NTRS)

    Taylor, G. Jeffrey

    2003-01-01

    Jupiter's moon Io is the most volcanically active body in the Solar System. Observations by instruments on the Galileo spacecraft and on telescopes atop Mauna Kea in Hawai'i indicate that lava flows on Io are surprisingly hot, over 1200 oC and possibly as much as 1300 oC; a few areas might have lava flows as hot as 1500 oC. Such high temperatures imply that the lava flows are composed of rock that formed by a very large amount of melting of Io's mantle. This has led Laszlo Keszthelyi and Alfred S. McEwen of the University of Arizona and me to reawaken an old hypothesis that suggests that the interior of Io is a partially-molten mush of crystals and magma. The idea, which had fallen out of favor for a decade or two, explains high-temperature hot spots, mountains, calderas, and volcanic plains on Io. If correct, Io gives us an opportunity to study processes that operate in huge, global magma systems, which scientists believe were important during the early history of the Moon and Earth, and possibly other planetary bodies as well. Though far from proven, the idea that Io has a ocean of mushy magma beneath its crust can be tested with measurements by future spacecraft.

  1. Jupiter Environment Tool

    NASA Technical Reports Server (NTRS)

    Sturm, Erick J.; Monahue, Kenneth M.; Biehl, James P.; Kokorowski, Michael; Ngalande, Cedrick,; Boedeker, Jordan

    2012-01-01

    The Jupiter Environment Tool (JET) is a custom UI plug-in for STK that provides an interface to Jupiter environment models for visualization and analysis. Users can visualize the different magnetic field models of Jupiter through various rendering methods, which are fully integrated within STK s 3D Window. This allows users to take snapshots and make animations of their scenarios with magnetic field visualizations. Analytical data can be accessed in the form of custom vectors. Given these custom vectors, users have access to magnetic field data in custom reports, graphs, access constraints, coverage analysis, and anywhere else vectors are used within STK.

  2. Estimating mixing in hot Jupiter atmospheres

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Lewis, Nikole; Lian, Yuan; Marley, Mark S.

    2016-10-01

    Ground- and space-based observations of exoplanets have shown that like solar system planets and brown dwarfs, clouds are ubiquitous in exoplanet atmospheres. However, the dynamics that underpin their formation and transport are still poorly understood. In order to further elucidate the three-dimensional mixing in exoplanet atmospheres, we present a generalized study comparing the dynamics of exoplanets to brown dwarfs and solar system planets. We utilize previously published hot Jupiter GCMs to estimate the microphysical timescales that dictate cloud formation and calculate horizontal and vertical wind profiles, and compare those to these other classes of substellar objects. In doing so, we can provide a framework for which to explain the small cloud particle sizes observed in hot Jupiters, and create a generalized profile for vertical mixing in hot Jupiter atmospheres.

  3. Jupiter Torus Diagram

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A cut-away schematic of Jupiter's space environment shows magnetically trapped radiation ions (in red), the neutral gas torus of the volcanic moon Io (green) and the newly discovered neutral gas torus of the moon Europa (blue). The white lines represent magnetic field lines.

    Energetic neutral atoms (ENA) are emitted from the Europa torus regions because of the interaction between the trapped ions and the neutral gases. The Magnetospheric Imaging Instrument on NASA's Cassini spacecraft imaged those energetic neutral atoms in early 2001 during Cassini's flyby of Jupiter. Energetic neutral atoms also come from Jupiter when radiation ions impinge onto Jupiter's upper atmosphere.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages Cassini for NASA's Office of Space Science, Washington, D.C.

  4. Juno: Launching to Jupiter

    NASA Video Gallery

    The Juno spacecraft will look deep beneath Jupiter's swirling curtains of clouds to decipher the planet's structure and history during a mission that will begin with a 5-year flight through deep sp...

  5. Color photography of Jupiter

    NASA Technical Reports Server (NTRS)

    Larson, S. M.; Fountain, J. W.; Mintor, R. B.

    1973-01-01

    Selected color photographs of Jupiter taken with the 154-cm Catalina reflector from October 1965 to September 1973 are presented. Eight oppositions are covered showing the developments in cloud belt structure and color distribution of the Jovian atmosphere.

  6. TOWARD CHEMICAL CONSTRAINTS ON HOT JUPITER MIGRATION

    SciTech Connect

    Madhusudhan, Nikku; Amin, Mustafa A.; Kennedy, Grant M.

    2014-10-10

    The origin of hot Jupiters—gas giant exoplanets orbiting very close to their host stars—is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses. In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily explained by giant planets forming at large orbital separations, either by core accretion or gravitational instability, and migrating to close-in orbits via disk-free mechanisms involving dynamical encounters. Such planets also contain solar or super-solar C/O ratios. On the contrary, hot Jupiters with super-solar O and C abundances can be explained by a variety of formation-migration pathways which, however, lead to solar or sub-solar C/O ratios. Current estimates of low oxygen abundances in hot Jupiter atmospheres may be indicative of disk-free migration mechanisms. We discuss open questions in this area which future studies will need to investigate.

  7. Jupiter's Dynamic Magnetosphere

    NASA Astrophysics Data System (ADS)

    Vogt, M. F.; Bunce, E. J.; Kronberg, E. A.; Jackman, C. M.

    2014-12-01

    Jupiter's magnetosphere is a highly dynamic environment. Hundreds of reconnection events have been identified in Jupiter's magnetotail through analysis of magnetic field and particle measurements collected by the Galileo spacecraft. Quasi-periodic behavior, suggestive of reconnection, has been intermittently observed on a ~2-3 day time scale in several data sets, including magnetic field dipolarizations, flow bursts, auroral polar dawn spots, and the hectometric radio emission. In this paper we review the present state of knowledge of Jovian magnetospheric dynamics. Throughout the discussion, we highlight similarities and differences to Saturn's magnetosphere. For example, recent analysis of plasmoid signatures at both Jupiter and Saturn has established the role of tail reconnection in the overall mass and flux transport in the outer planet magnetospheres. The results for both Jupiter and Saturn suggest that the observed mass loss rate due to tail reconnection and plasmoid release is insufficient to account for the mass input rate from the moons Io and Enceladus, respectively. We also present new analysis in which we use the Michigan mSWiM propagated solar wind MHD model to estimate the solar wind conditions upstream of Jupiter. This information allows us to determine whether reconnection events occur preferentially during certain solar wind conditions, or whether there is evidence that the solar wind modulates the quasi-periodicity seen in the field dipolarizations and flow bursts.

  8. Full Jupiter Mosaic

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image of Jupiter is produced from a 2x2 mosaic of photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI), and assembled by the LORRI team at the Johns Hopkins University Applied Physics Laboratory. The telescopic camera snapped the images during a 3-minute, 35-second span on February 10, when the spacecraft was 29 million kilometers (18 million miles) from Jupiter. At this distance, Jupiter's diameter was 1,015 LORRI pixels -- nearly filling the imager's entire (1,024-by-1,024 pixel) field of view. Features as small as 290 kilometers (180 miles) are visible.

    Both the Great Red Spot and Little Red Spot are visible in the image, on the left and lower right, respectively. The apparent 'storm' on the planet's right limb is a section of the south tropical zone that has been detached from the region to its west (or left) by a 'disturbance' that scientists and amateur astronomers are watching closely.

    At the time LORRI took these images, New Horizons was 820 million kilometers (510 million miles) from home -- nearly 51/2 times the distance between the Sun and Earth. This is the last full-disk image of Jupiter LORRI will produce, since Jupiter is appearing larger as New Horizons draws closer, and the imager will start to focus on specific areas of the planet for higher-resolution studies.

  9. Polar Atmospheric Dynamics of Jupiter

    NASA Astrophysics Data System (ADS)

    Sayanagi, Kunio M.; Mitchell, J. L.; Heavens, N. G.

    2012-10-01

    We investigate the transition in Jupiter's atmospheric dynamic regime between mid-latitudes to polar regions. Spacecraft observations of Jupiter have identified three distinct dynamical regimes in the cloud-top winds. In the equatorial region, a fast, broad jetstream blows eastward where no vortices are found. In the mid-latitudes, many vortices exist between the numerous jetstreams that alternate in wind direction between eastward and westward. On Jupiter, vortices become increasingly prevalent with latitude; poleward of 65 degree N/S latitudes, the banded structure that characterizes the lower latitudes becomes indiscernible, and the flow acquires an increasingly turbulent appearance with little zonal organization - we identify this regime as polar turbulence. Saturn also has a very similarly organized atmosphere, except that it maintains zonally organized cloud bands up to the poles and lacks polar turbulence. The zonal structure of Saturn culminates in the southern hemisphere with a hurricane-like cyclonic vortex residing precisely at south pole. Here, we focus on the transition from the mixed jet-vortex regime in the mid-latitudes to the vortex-dominated polar-regime of Jupiter. Using an idealized shallow-water model in a beta-plane channel, we test the stability of various scenarios that range between a jet-dominated flow and vortical turbulence. Since we are simulating a zone on the sphere rather than the full circulation, we test the sensitivity of the dynamics to latitude by varying the model’s beta-plane parameters, namely, the background Coriolis parameter f0 and its gradient beta. In addition, as we employ a 1 1/2-layer shallow-water model, we also vary the layer thickness and the bottom-layer topography to mimic a steeply varying thermal stratification (i.e., a potential vorticity front) by exploiting the topographic beta effects. We use the EPIC model (Dowling et al. 1998) to perform our numerical experiments. Our study is supported by a NASA Outer

  10. Physics of Jupiter's Gossamer Rings

    NASA Astrophysics Data System (ADS)

    Hamilton, Douglas P.; Krueger, H.

    2007-10-01

    Thebe's gossamer ring, the outermost and faintest of Jupiter's rings, has an outward extension that we have previously argued is due to a shadow resonance (Hamilton 2003, DPS meeting #35, #11.09). A shadow resonance arises from the abrupt shutoff of photoelectric charging when a dust particle enters Jupiter's shadow which, in turn, affects the strength of the electromagnetic perturbation from the planet's intense magnetic field. The result is a coupled oscillation between a particle's orbital eccentricity and its semimajor axis. Ring material spreads outward from Thebe while maintaining its vertical thickness just as observed by Galileo imaging. In addition to cameras, the Galileo spacecraft was also equipped with dust and plasma detectors. The spacecraft made two passes through the ring and its dust detector found that 1) dust fluxes drop immediately interior to Thebe's orbit, 2) some grains have inclinations in excess of 20 degrees and 3) submicron particles are present in the Amalthea ring in much greater numbers than in the Thebe ring. These findings can all be explained in the context of our shadow resonance model: the inner boundary is a direct consequence of the conservation of the Electromagnetic Jacobi Constant, the high inclinations are forced by a vertical resonance, and the excess submicron particles are a consequence of the weakening of electromagnetic forces in the vicinity of synchronous orbit. In this talk, we will present the data sets as well as detailed numerical simulations that back up these claims.

  11. A Preliminary Jupiter Model

    NASA Astrophysics Data System (ADS)

    Hubbard, W. B.; Militzer, B.

    2016-03-01

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen-helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen-helium-rich envelope with approximately three times solar metallicity.

  12. Jupiter Polar Winds Movie

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Bands of eastward and westward winds on Jupiter appear as concentric rotating circles in this movie composed of Cassini spacecraft images that have been re-projected as if the viewer were looking down at Jupiter's north pole and the planet were flattened.

    The sequence covers 70 days, from October 1 to December 9, 2000. Cassini's narrow-angle camera captured the images of Jupiter's atmosphere in the near-infrared region of the spectrum.

    What is surprising in this view is the coherent nature of the high-latitude flows, despite the very chaotic, mottled and non-banded appearance of the planet's polar regions. This is the first extended movie sequence to show the coherence and longevity of winds near the pole and the features blown around the planet by them.

    There are thousands of spots, each an active storm similar to the size to the largest of storms on Earth. Large terrestrial storms usually last only a week before they dissolve and are replaced by other storms. But many of the Jovian storms seen here, while occasionally changing latitude or merging with each other, persist for the entire 70 days. Until now, the lifetime of the high-latitude features was unknown. Their longevity is a mystery of Jovian weather.

    Cassini collected images of Jupiter for months before and after it passed the planet on December 30, 2000. Six or more images of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire sequence was repeated generally every other Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours.

    The images used for the movie shown here were taken every 20 hours through a filter centered at a wavelength of 756 nanometers, where there are almost no absorptions in the planet's atmosphere. The images covering each rotation were mosaiced together to form a cylindrical map extending from 75 degrees north to 75 degrees south in

  13. Jupiter's Rings: Sharpest View

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter. The top image was taken on approach, showing three well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings, as well as lesser amounts of material between the rings. New Horizons snapped the lower image after it had passed Jupiter on February 28, 2007, and looked back in a direction toward the sun. The image is sharply focused, though it appears fuzzy due to the cloud of dust-sized particles enveloping the rings. The dust is brightly illuminated in the same way the dust on a dirty windshield lights up when you drive toward a 'low' sun. The narrow rings are confined in their orbits by small 'shepherding' moons.

  14. Voyager 1 examines Jupiter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    An overview of the Voyager mission to Jupiter, Saturn, and possibly Uranus is presented. Scientific instruments onboard the spacecraft are described as well as methods used for their calibration and evaluation during the cruise phase of the mission. Experiments to be performed cover the following areas: imaging science, radio science, cosmic rays, ultraviolet spectroscopy, photopolarimetry, planetary radio astronomy, magnetic fields, low-energy charged particles, plasma science, and infrared radiometry and spectroscopy. A list of the satellites of Jupiter and their diameters, distances, and periods is included.

  15. Exobiology, Jupiter and life.

    NASA Technical Reports Server (NTRS)

    Molton, P. M.

    1972-01-01

    Recent experiments in an environmental chamber have shown that not even hardy terrestrial bacteria can survive on the Martian surface. The planet Jupiter is now considered by many to be the most likely place to find nonterrestrial life. Atmospheric simulation experiments for Jupiter that have been performed involve spark or semicorona discharges in mixtures of methane and ammonia at room temperature and a pressure lower than atmospheric. Terrestrial microorganisms have been shown capable of surviving 24 hr under a range of possible Jovian atmospheric conditions. The final mode of approach to the question of Jovian life concerns theoretical studies on the sort of chemical systems from which life could be generated.

  16. Jupiter's outer atmosphere.

    NASA Technical Reports Server (NTRS)

    Brice, N. M.

    1973-01-01

    The current state of the theory of Jupiter's outer atmosphere is briefly reviewed. The similarities and dissimilarities between the terrestrial and Jovian upper atmospheres are discussed, including the interaction of the solar wind with the planetary magnetic fields. Estimates of Jovian parameters are given, including magnetosphere and auroral zone sizes, ionospheric conductivity, energy inputs, and solar wind parameters at Jupiter. The influence of the large centrifugal force on the cold plasma distribution is considered. The Jovian Van Allen belt is attributed to solar wind particles diffused in toward the planet by dynamo electric fields from ionospheric neutral winds, and the consequences of this theory are indicated.

  17. Virtual Jupiter - Real Learning

    NASA Astrophysics Data System (ADS)

    Ruzhitskaya, Lanika; Speck, A.; Laffey, J.

    2010-01-01

    How many earthlings went to visit Jupiter? None. How many students visited virtual Jupiter to fulfill their introductory astronomy courses’ requirements? Within next six months over 100 students from University of Missouri will get a chance to explore the planet and its Galilean Moons using a 3D virtual environment created especially for them to learn Kepler's and Newton's laws, eclipses, parallax, and other concepts in astronomy. The virtual world of Jupiter system is a unique 3D environment that allows students to learn course material - physical laws and concepts in astronomy - while engaging them into exploration of the Jupiter's system, encouraging their imagination, curiosity, and motivation. The virtual learning environment let students to work individually or collaborate with their teammates. The 3D world is also a great opportunity for research in astronomy education to investigate impact of social interaction, gaming features, and use of manipulatives offered by a learning tool on students’ motivation and learning outcomes. Use of 3D environment is also a valuable source for exploration of how the learners’ spatial awareness can be enhanced by working in 3-dimensional environment.

  18. Jupiter Atmospheric Map

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Huge cyclonic storms, the Great Red Spot and the Little Red Spot, and wispy cloud patterns are seen in fascinating detail in this map of Jupiter's atmosphere obtained January 14-15, 2007, by the New Horizons Long Range Reconnaissance Imager (LORRI).

    The map combines information from 11 different LORRI images that were taken every hour over a 10-hour period -- a full Jovian day -- from 17:42 UTC on January 14 to 03:42 UTC on January 15. The New Horizons spacecraft was approximately 72 million kilometers (45 million miles) from Jupiter at the time.

    The LORRI pixels on the 'globe' of Jupiter were projected onto a rectilinear grid, similar to the way flat maps of Earth are created. The LORRI pixel intensities were corrected so that every point on the map appears as if the sun were directly overhead; some image sharpening was also applied to enhance detail. The polar regions of Jupiter are not shown on the map because the LORRI images do not sample those latitudes very well and artifacts are produced during the map-projection process.

  19. Jupiter's Big Bang.

    ERIC Educational Resources Information Center

    McDonald, Kim A.

    1994-01-01

    Collision of a comet with Jupiter beginning July 16, 1994 will be observed by astronomers worldwide, with computerized information relayed to a center at the University of Maryland, financed by the National Aeronautics and Space Administration and National Science Foundation. Geologists and paleontologists also hope to learn more about earth's…

  20. Multicolor photography of Jupiter.

    NASA Technical Reports Server (NTRS)

    Fountain, J. W.; Larson, S. M.

    1973-01-01

    Representative multicolor Jupiter photographs taken with wideband filters in 1965 and 1970 are discussed. Attention is given to the Red Spot and to the differences in methane absorption above the clouds. A table of observational data and white-and-black reproductions of representative photographs with interpretation are included.

  1. Jupiter: As a planet. [its physical characteristics and radio waves emitted from Jupiter

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The planet Jupiter, its planetary mass and atmosphere, radio waves emitted from Jupiter, thermal radiation, internal structure of Jupiter, and the possibility of life on Jupiter are discussed. Educational study projects are included.

  2. Jupiter - Solid or Gaseous? Ask Juno

    NASA Astrophysics Data System (ADS)

    Ackerman, J. A., Jr.

    2015-12-01

    Data from Cassini, Galileo, S-L 9 and Ulysses suggest Jupiter and Saturn are solid, frozen, Methane Gas Hydrate (MGH) planets. The bulk of these giants formed slow and cold by the natural accretion of snowflakes at their current orbital radii in the presence of methane, forming rigid incompressible bodies. MGH, (CH4)8(H2O)46 (d=0.9), is consistent with the abundances of the elements comprising the Earth (H>O>C). Their combined MGH comprises >250 earth-masses of H2O. Jupiter (d=1.33) incorporated most of the heavy elements in the nascent solar system, exemplified by an enormously enhanced D/H. The temperature excess of Jupiter's atmosphere is the result of an impact ~6,000 years BP, triggering an incredibly energetic fusion explosion which ejected the masses of the proto-Galilean moons. It also initiated a continuing fusion furnace in the crater producing a jet of hot gases extending >2x106 km, beyond Callisto. The jet has slowly diminished over 6,000 years, resulting in the differences in the four Galilean Moons. The mass ejection (ang. mom.) slowed Jupiter's rotation until ~1930, currently interpreted as a drift of the Great Red Spot. A diminishing fusion reaction (D + p → 3He + γ) continues to this day, producing Jupiter's atmospheric 'temperature excess'. Jupiter's rapid rotation deflects the rising vortex of hot gases from the fusion reaction horizontally, driving multiple zonal vortices, constrained by the frozen MGH surface <1000 km below the cloud tops. It appears as the tilted Great Red Spot (GRS), ~30,000 km to the west of the crater at 22 o S Lat., which has remained unchanged in the last 350 years - impossible due to the enormous Coliolis effect. Streams of 3He produced in the fusion reaction exiting Jupiter through the center of the GRS have been detected by the Galileo probe and orbiter, Ulysses, and Cassini. The fusion releases methane, also heavy elements which oxidize as they rise, producing the cloud-top colors. The MGH hypothesis explains the

  3. Too Little, Too Late: How the Tidal Evolution of Hot Jupiters Affects Transit Surveys of Clusters

    NASA Technical Reports Server (NTRS)

    Debes, John H.; Jackson, Brian

    2010-01-01

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  4. TOO LITTLE, TOO LATE: HOW THE TIDAL EVOLUTION OF HOT JUPITERS AFFECTS TRANSIT SURVEYS OF CLUSTERS

    SciTech Connect

    Debes, John H.; Jackson, Brian

    2010-11-10

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense Hubble Space Telescope search for transits. We find that in older clusters, one expects to detect fewer transiting planets by a factor of 2 for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of the semimajor axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  5. Rubble around Jupiter

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    NASA's Jet Propulsion Laboratory has announced that Amalthea, a 270-km-long, potato-shaped inner moon of Jupiter, "apparently is a loosely packed pile of rubble," with empty space where the rubble does not fit well together.This is among the new findings about the moon announced by JPL astronomer John Anderson and his colleagues on 9 December at the AGU Fall Meeting in San Francisco.

  6. Rubble around Jupiter

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    NASA's Jet Propulsion Laboratory has announced that Amalthea, a 270-km-long, potato-shaped inner moon of Jupiter, “apparently is a loosely packed pile of rubble,” with empty space where the rubble does not fit well together.This is among the new findings about the moon announced by JPL astronomer John Anderson and his colleagues on 9 December at the AGU Fall Meeting in San Francisco.

  7. Jupiter-Io Montage

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This is a montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft's Jupiter flyby in early 2007. The Jupiter image is an infrared color composite taken by the spacecraft's near-infrared imaging spectrometer, the Linear Etalon Imaging Spectral Array (LEISA) at 1:40 UT on Feb. 28, 2007. The infrared wavelengths used (red: 1.59 um, green: 1.94 um, blue: 1.85 um) highlight variations in the altitude of the Jovian cloud tops, with blue denoting high-altitude clouds and hazes, and red indicating deeper clouds. The prominent bluish-white oval is the Great Red Spot. The observation was made at a solar phase angle of 75 degrees but has been projected onto a crescent to remove distortion caused by Jupiter's rotation during the scan. The Io image, taken at 00:25 UT on March 1st 2007, is an approximately true-color composite taken by the panchromatic Long-Range Reconnaissance Imager (LORRI), with color information provided by the 0.5 um ('blue') and 0.9 um ('methane') channels of the Multispectral Visible Imaging Camera (MVIC). The image shows a major eruption in progress on Io's night side, at the northern volcano Tvashtar. Incandescent lava glows red beneath a 330-kilometer high volcanic plume, whose uppermost portions are illuminated by sunlight. The plume appears blue due to scattering of light by small particles in the plume

    This montage appears on the cover of the Oct. 12, 2007, issue of Science magazine.

  8. Physics of Jupiter's Gossamer Rings

    NASA Astrophysics Data System (ADS)

    Hamilton, Douglas P.; Krueger, H.

    2008-05-01

    Thebe's gossamer ring, the outermost and faintest of Jupiter's rings, extends outward by at least half a jovian radius from its source satellite while maintaining a constant vertical thickness. This structure is created by an electromagnetic perturbation known as a shadow resonance (Hamilton 2003, DPS meeting #35, #11.09). A shadow resonance arises from the abrupt shutoff of photoelectric charging when a dust particle enters Jupiter's shadow which, in turn, affects the strength of the electromagnetic perturbation from the planet's intense magnetic field. The result is a coupled oscillation between a particle's orbital eccentricity and its semimajor axis. Ring material spreads outward from Thebe while maintaining its vertical thickness just as observed by Galileo imaging. In addition to cameras, the Galileo spacecraft was also equipped with dust and plasma detectors. The spacecraft made two passes through the ring and its dust detector found that 1) dust fluxes drop immediately interior to Thebe's orbit, 2) some grains have inclinations in excess of 20 degrees and 3) submicron particles are present in the Amalthea ring in much greater numbers than in the Thebe ring. These findings can all be explained in the context of our shadow resonance model: the inner boundary is a direct consequence of the conservation of the Electromagnetic Jacobi Constant, the high inclinations are forced by a vertical version of the shadow resonance, and the excess submicron particles are a consequence of the weakening of electromagnetic forces in the vicinity of synchronous orbit. In this talk, we will present the data sets as well as detailed numerical simulations that back up these claims.

  9. Voyager picture of Jupiter

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA's Voyager 1 took this picture of the planet Jupiter on Saturday, Jan. 6, the first in its three-month-long, close-up investigation of the largest planet. The spacecraft, flying toward a March 5 closest approach, was 35.8 million miles (57.6 million kilometers) from Jupiter and 371.7 million miles (598.2 million kilometers) from Earth when the picture was taken. As the Voyager cameras begin their meteorological surveillance of Jupiter, they reveal a dynamic atmosphere with more convective structure than had previously been thought. While the smallest atmospheric features seen in this picture are still as large as 600 miles (1,000 kilometers) across, Voyager will be able to detect individual storm systems as small as 3 miles (5 kilometers) at closest approach. The Great Red Spot can be seen near the limb at the far right. Most of the other features are too small to be seen in terrestrial telescopes. This picture was transmitted to the Jet Propulsion Laboratory through the Deep Space Network's tracking station at Madrid, Spain. The Voyager Project is managed for NASA by Caltech's Jet Propulsion Laboratory.

  10. Understanding Jupiter's interior

    NASA Astrophysics Data System (ADS)

    Militzer, Burkhard; Soubiran, François; Wahl, Sean M.; Hubbard, William

    2016-09-01

    This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provided constraints for the interior structure of Jupiter. We discuss typical three-layer interior models that consist of a dense central core and an inner metallic and an outer molecular hydrogen-helium layer. These models rely heavily on experiments, analytical theory, and first-principles computer simulations of hydrogen and helium to understand their behavior up to the extreme pressures ˜10 Mbar and temperatures ˜10,000 K. We review the various equations of state used in Jupiter models and compare them with shock wave experiments. We discuss the possibility that helium rain, core erosion, and double diffusive convection have affected the structure and evolution of giant planets. In July 2016 the Juno spacecraft entered orbit around Jupiter, promising high-precision measurements of the gravitational field that will allow us to test our understanding of gas giant interiors better than ever before.

  11. Diffusion models for Jupiter's radiation belt

    NASA Technical Reports Server (NTRS)

    Jacques, S. A.; Davis, L., Jr.

    1972-01-01

    Solutions are given for the diffusion of trapped particles in a planetary magnetic field in which the first and second adiabatic invariants are preserved but the third is not, using as boundary conditions a fixed density at the outer boundary (the magnetopause) and a zero density at an inner boundary (the planetary surface). Losses to an orbiting natural satellite are included and an approximate evaluation is made of the effects of the synchrotron radiation on the energy of relativistic electrons. Choosing parameters appropriate to Jupiter, the electrons required to produce the observed synchrotron radiation are explained. If a speculative mechanism in which the diffusion is driven by ionospheric wind is the true explanation of the electrons producing the synchrotron emission it can be concluded that Jupiter's inner magnetosphere is occupied by an energetic proton flux that would be a serious hazard to spacecraft.

  12. Voyager 2 Jupiter Eruption Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie records an eruptive event in the southern hemisphere of Jupiter over a period of 8 Jupiter days. Prior to the event, an undistinguished oval cloud mass cruised through the turbulent atmosphere. The eruption occurs over avery short time at the very center of the cloud. The white eruptive material is swirled about by the internal wind patterns of the cloud. As a result of the eruption, the cloud then becomes a type of feature seen elsewhere on Jupiter known as 'spaghetti bowls'.

    As Voyager 2 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 8 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Violet filter around May 6, 1979. The spacecraft was about 50 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  13. A Day on Jupiter (Animation)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This 'movie' strings 11 images of Jupiter captured by the New Horizons Long Range Reconnaissance Imager (LORRI) on January 9, 2007, when the spacecraft was about 80 million kilometers (49.6 million miles) from the giant planet. The sequence covers a full 10-hour rotation of Jupiter, during which the moons Ganymede and Io -- as well as the shadows they cast on Jupiter -- move across the camera's field of view.

  14. Dynamical Interactions Make Hot Jupiters in Open Star Clusters

    NASA Astrophysics Data System (ADS)

    Shara, Michael M.; Hurley, Jarrod R.; Mardling, Rosemary A.

    2016-01-01

    Explaining the origin and evolution of exoplanetary hot Jupiters remains a significant challenge. One possible mechanism for the production of hot Jupiters is planet-planet interactions, which produce them from planets born far from their host stars but near their dynamical stability limits. In the much more likely case of planets born far from their dynamical stability limits, can hot Jupiters be formed in star clusters? Our N-body simulations answer this question in the affirmative, and show that hot Jupiter formation is not a rare event, occurring in ˜1% of star cluster planetary systems. We detail three case studies of the dynamics-induced births of hot Jupiters on highly eccentric orbits that can only occur inside star clusters. The hot Jupiters’ orbits bear remarkable similarities to those of some of the most extreme exoplanets known: HAT-P-32b, HAT-P-2b, HD 80606b, and GJ 876d. If stellar perturbations formed these hot Jupiters, then our simulations predict that these very hot inner planets are often accompanied by much more distant gas giants in highly eccentric orbits.

  15. Heliospheric Electrons from Jupiter

    NASA Astrophysics Data System (ADS)

    Gomez-Herrero, R.; Rodriguez-Frias, M. D.; del Peral, L.; Sequeiros, J.; Mueller-Mellin, R.; Kunow, H.

    2001-08-01

    The electron spectrum in the energy range 250 keV to 10 MeV measured by EPHIN sensor onboard SOHO observatory during 1996 quiet time periods is presented. The results show that the dominant electron population is of Jovian origin. The spectral indexes obtained range from 1.5 to 1.8 in this work an estimation of the emission intensity of electrons from the Jovian magnetosphere is also obtained. Unexpected recurrence of Jovian electrons at the middle of 1996, during poor EarthJupiter magnetic connection has been observed.

  16. Pioneer 11 Encounter. [with Jupiter

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Pioneer 11's encounter with Jupiter is discussed in detail. The scientific experiments carried out on the probe are described along with the instruments used. Tables are included which provide data on the times of experiments, encounters, and the distances from Jupiter. Educational study projects are also given.

  17. Jupiter: Lord of the Planets.

    ERIC Educational Resources Information Center

    Kaufmann, William

    1984-01-01

    Presents a chapter from an introductory college-level astronomy textbook in which full-color photographs and numerous diagrams highlight an extensive description of the planet Jupiter. Topics include Jupiter's geology, rotation, magnetic field, atmosphere (including clouds and winds), and the Great Red Spot. (DH)

  18. CAPTURE OF TROJANS BY JUMPING JUPITER

    SciTech Connect

    Nesvorny, David; Vokrouhlicky, David; Morbidelli, Alessandro

    2013-05-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to {approx}5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) Multiplication-Sign 10{sup -7} for each particle in the original transplanetary disk, implying that the disk contained (3-4) Multiplication-Sign 10{sup 7} planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M{sub disk} {approx} 14-28 M{sub Earth}, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  19. Capture of irregular satellites at Jupiter

    SciTech Connect

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio

    2014-03-20

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10{sup –8}. This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  20. The Giant Planet Jupiter

    NASA Astrophysics Data System (ADS)

    Rogers, John H.

    2009-07-01

    Part I. Observing Jupiter: 1. Observations from Earth; 2. Observations from spacecraft; Part II. The Visible Structure of the Atmosphere: 3. Horizontal structure: belts, currents, spots and storms; 4. Vertical structure: colours and clouds; Part III. The Observational Record of the Atmosphere: 5. The Polar Region; 6. North North Temperate Regions (57°N to 35°N); 7. North Temperate Region (35°N to 23°N); 8. North Tropical Region (23°N to 9°N); 9. Equatorial Region (9°N to 9°S); 10. South Tropical Region (9°S to 27°S); 11. South Temperate Region (27°S to 37°S); 12. South South Temperate Region (37°S to 53°S); Part IV: The Physics and Chemistry of the Atmosphere: 13. Possible large-scale and long-term patterns; 14. The dynamics of individual spots; 15. Theoretical models of the atmosphere; 16. The composition of the planet; Part V. The Electrodynamic Environment of Jupiter: 17. Lights in the Jovian night; 18. The magnetosphere and radiation belts; Part VI. The Satellites: 19. The inner satellites and the ring; 20. The Galilean satellites; 21. Io; 22. Europa; 23. Ganymede; 24. Callisto; 25. The outer satellites; Appendices: 1. Measurement of longitude; 2. Measurement of latitude; 3. Lists of apparitions and published reports; 4. Bibliography (The planet); 5. Bibliography (The magnetosphere and satellites); Index.

  1. Jupiter G Impact Evolution

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This mosaic of WFPC-2 images shows the evolution of the Shoemaker-Levy 9 G impact site on Jupiter. The images from lower left to upper right show: the impact plume at 07/18/94 07:38 UT (about 5 minutes after the impact); the fresh impact site at 07/18/94 at 09:19 UT (1.5 hours after impact); the impact site after evolution by the winds of Jupiter (left), along with the L impact (right), taken on 07/21/94 at 6:22 UT (3 days after the G impact and 1.3 days after the L impact); and further evolution of the G and L sites due to winds and an additional impact (S) in the G vicinity, taken on 07/23/94 at 08:08 UT (5 days after the G impact).

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  2. SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

    SciTech Connect

    Wu Yanqin; Lithwick, Yoram

    2011-07-10

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term 'secular migration') explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the 'warm Jupiters' at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  3. Secular Chaos and the Production of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Wu, Yanqin; Lithwick, Yoram

    2011-07-01

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term "secular migration") explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the "warm Jupiters" at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  4. Jupiter's Moons: Family Portrait

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This montage shows the best views of Jupiter's four large and diverse 'Galilean' satellites as seen by the Long Range Reconnaissance Imager (LORRI) on the New Horizons spacecraft during its flyby of Jupiter in late February 2007. The four moons are, from left to right: Io, Europa, Ganymede and Callisto. The images have been scaled to represent the true relative sizes of the four moons and are arranged in their order from Jupiter.

    Io, 3,640 kilometers (2,260 miles) in diameter, was imaged at 03:50 Universal Time on February 28 from a range of 2.7 million kilometers (1.7 million miles). The original image scale was 13 kilometers per pixel, and the image is centered at Io coordinates 6 degrees south, 22 degrees west. Io is notable for its active volcanism, which New Horizons has studied extensively.

    Europa, 3,120 kilometers (1,938 miles) in diameter, was imaged at 01:28 Universal Time on February 28 from a range of 3 million kilometers (1.8 million miles). The original image scale was 15 kilometers per pixel, and the image is centered at Europa coordinates 6 degrees south, 347 degrees west. Europa's smooth, icy surface likely conceals an ocean of liquid water. New Horizons obtained data on Europa's surface composition and imaged subtle surface features, and analysis of these data may provide new information about the ocean and the icy shell that covers it.

    New Horizons spied Ganymede, 5,262 kilometers (3,268 miles) in diameter, at 10:01 Universal Time on February 27 from 3.5 million kilometers (2.2 million miles) away. The original scale was 17 kilometers per pixel, and the image is centered at Ganymede coordinates 6 degrees south, 38 degrees west. Ganymede, the largest moon in the solar system, has a dirty ice surface cut by fractures and peppered by impact craters. New Horizons' infrared observations may provide insight into the composition of the moon's surface and interior.

    Callisto, 4,820 kilometers (2,995 miles) in diameter, was imaged

  5. Constraining Planetary Migration Mechanisms with Highly Eccentric Hot Jupiter Progenitors

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, J. A.; Murray-Clay, R.; Morton, T.; Crepp, J. R.; Fabrycky, D. C.; Howard, A.

    2013-01-01

    Abstract: Hot Jupiters --- Jupiter-mass planets orbiting within 0.1 AU of their host stars --- are unlikely to have formed in situ and thus serve as evidence for the prevalence of planetary migration. However, it is debated whether the typical hot Jupiter migrated smoothly inward through the protoplanetary disk or was perturbed onto an eccentric orbit, which tidal dissipation subsequently shrank and circularized during close passages to the star. In the latter class of model, the perturber may be a stellar or planetary companion, which causes the Jupiter to undergo a temporary epoch with high eccentricity (e> 0.9). Socrates and et al. (2012) predicted that these super-eccentric hot Jupiter progenitors should be readily discoverable through the transit method by the Kepler Mission. However, eccentricities of individual transiting planets primarily come from Doppler measurements, which are unfortunately precluded by the faintness of most Kepler targets. To solve this problem, we developed a Bayesian method (the “photoeccentric effect”) for measuring an individual planet's eccentricity solely from its Kepler light curve, allowing for a tight measurement of large eccentricities. We applied this new approach to the Kepler giant planet candidates and identified KOI-1474.01 as an eccentric planet (e = 0.81+0.10/-0.07) with an average orbital period of 69.7340 days, varying by approximately 1 hour due to perturbations by a massive outer companion, which is possibly the culprit responsible for KOI-1474.01’s highly eccentric orbit. KOI-1474.01 is likely a failed hot Jupiter, too far from its host star to be tidally transformed into a hot Jupiter. We found a significant lack of super-eccentric proto-hot Jupiters compared to the number expected, allowing us to place a strong upper limit on the fraction of hot Jupiters created by stellar binaries. Our results are consistent with disks or planetary companions being the primary channel for hot Jupiter creation. Supported by

  6. Jupiter and the Voyager mission

    USGS Publications Warehouse

    Soderblom, L.; Spall, Henry

    1980-01-01

    In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year. 

  7. Ganymede and Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The solar system's largest moon, Ganymede, is captured here alongside the planet Jupiter in a color picture taken by NASA's Cassini spacecraft on Dec. 3, 2000.

    Ganymede is larger than the planets Mercury and Pluto and Saturn's largest moon, Titan. Both Ganymede and Titan have greater surface area than the entire Eurasian continent on our planet. Cassini was 26.5 million kilometers (16.5 million miles) from Ganymede when this image was taken. The smallest visible features are about 160 kilometers (about 100 miles) across.

    The bright area near the south (bottom) of Ganymede is Osiris, a large, relatively new crater surrounded by bright icy material ejected by the impact, which created it. Elsewhere, Ganymede displays dark terrains that NASA's Voyager and Galileo spacecraft have shown to be old and heavily cratered. The brighter terrains are younger and laced by grooves. Various kinds of grooved terrains have been seen on many icy moons in the solar system. These are believed to be the surface expressions of warm, pristine, water-rich materials that moved to the surface and froze.

    Ganymede has proven to be a fascinating world, the only moon known to have a magnetosphere, or magnetic environment, produced by a convecting metal core. The interaction of Ganymede's and Jupiter's magnetospheres may produce dazzling variations in the auroral glows in Ganymede's tenuous atmosphere of oxygen.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  8. Jupiter Clouds in Depth

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] 619 nm [figure removed for brevity, see original site] 727 nm [figure removed for brevity, see original site] 890 nm

    Images from NASA's Cassini spacecraft using three different filters reveal cloud structures and movements at different depths in the atmosphere around Jupiter's south pole.

    Cassini's cameras come equipped with filters that sample three wavelengths where methane gas absorbs light. These are in the red at 619 nanometer (nm) wavelength and in the near-infrared at 727 nm and 890 nm. Absorption in the 619 nm filter is weak. It is stronger in the 727 nm band and very strong in the 890 nm band where 90 percent of the light is absorbed by methane gas. Light in the weakest band can penetrate the deepest into Jupiter's atmosphere. It is sensitive to the amount of cloud and haze down to the pressure of the water cloud, which lies at a depth where pressure is about 6 times the atmospheric pressure at sea level on the Earth). Light in the strongest methane band is absorbed at high altitude and is sensitive only to the ammonia cloud level and higher (pressures less than about one-half of Earth's atmospheric pressure) and the middle methane band is sensitive to the ammonia and ammonium hydrosulfide cloud layers as deep as two times Earth's atmospheric pressure.

    The images shown here demonstrate the power of these filters in studies of cloud stratigraphy. The images cover latitudes from about 15 degrees north at the top down to the southern polar region at the bottom. The left and middle images are ratios, the image in the methane filter divided by the image at a nearby wavelength outside the methane band. Using ratios emphasizes where contrast is due to methane absorption and not to other factors, such as the absorptive properties of the cloud particles, which influence contrast at all wavelengths.

    The most prominent feature seen in all three filters is the polar stratospheric haze that makes Jupiter

  9. Oscillating ion streamline model of Jupiter's neutral sodium nebula

    NASA Astrophysics Data System (ADS)

    Flynn, Brian

    1993-10-01

    Recent observations of neutral sodium D line emissions within 10 jovian radii (RJ) of Jupiter have led to the proposal of a new mechanism for the production of fast neutral sodium. The mechanism involves corotating, sodium-bearing molecular ions from Io's exosphere which undergo dissociation and/or dissociative recombination, resulting in fast neutral sodium atoms on escape trajectories from Jupiter. Fast neutral sodium atoms ejected near Io are also required to explain observations of the 1000 RJ-wide neutral sodium nebula surrounding Jupiter. A new Monte Carlo model explicitly computes particle trajectories resulting from molecular ion velocities at the time of dissociation or dissociative recombination. Initial simulations compare favorably with the general morphology of the nebula. Model estimates of nebula parameters are given.

  10. The Effect of Gravity Waves on Jupiter's Middle Atmosphere

    NASA Astrophysics Data System (ADS)

    Yelle, R. V.; Young, L. A.; Young, R. E.

    1998-09-01

    The temperature profile of Jupiter's middle atmosphere exhibits numerous fluctuations that are likely the manifestation of gravity waves. The amplitude of the temperature perturbations are large enough for non-linear effects on the wave propagation, the interaction among waves, and the interaction between waves and the background atmosphere to be important. As a consequence wave propagation and dissipation affects the energy balance, momentum balance, and diffusion of trace species in the middle atmosphere. We adapt theories for wave-wave interaction developed for the terrestrial atmosphere to Jupiter's atmosphere and extend them to include dissipation by molecular viscosity and thermal conduction. Although definitive conclusions are limited by our knowledge of the wave spectrum on Jupiter, we find that wave-wave interactions in the presence of these molecular effects can explain the observed levels of turbulent mixing and dynamical heating in the middle atmosphere.

  11. XMM-Newton X-Ray Observation of Jupiter

    NASA Technical Reports Server (NTRS)

    Waite, J. Hunter

    2005-01-01

    Soft X-ray emission has been observed from the disk of both Jupiter and Saturn as well as from the auroral regions of these planets. The low-latitude disk emission as observed by ROSAT, the Chandra X-Ray Observatory, and XMM-Newton appears to be uniformly distributed across the disk and to be correlated with solar activity. These characteristics suggest that the disk x-rays are produced by: (1) the elastic scattering of solar X-rays by atmospheric neutrals and (2) the absorption of solar X-rays in the carbon K-shell followed by fluorescent emission. The carbon atoms are found in methane molecules located below the homopause. In this paper we present the results of calculations of the scattering albedo for soft x-rays. We also show the calculated x-ray intensity for a range of atmospheric abundances for Jupiter and Saturn and for a number of solar irradiance spectra. The model calculations are compared with recent x-ray observations of Jupiter and Saturn. We conclude that the emission of soft x-rays from the disks of Jupiter and Saturn can be largely explained by the scattering and fluorescence of soft x-rays. We suggest that measured x-ray intensities from the disk regions of Jupiter

  12. Transitions in the cloud composition of hot Jupiters

    NASA Astrophysics Data System (ADS)

    Parmentier, Vivien; Fortney, Jonathan J.; Showman, Adam; Morley, Caroline; Marley, Mark S.

    2016-10-01

    Over a large range of equilibrium temperatures, clouds shape the transmission spectrum of hot Jupiter atmospheres, yet their composition remains unknown. Recent observations show that the Kepler lightcurves of some hot Jupiters are asymmetric: for the hottest planets, the lightcurve peaks before secondary eclipse, whereas for planets cooler than 1900K, it peaks after secondary eclipse. We use the thermal structure from 3D global circulation models to determine the expected cloud distribution and Kepler lightcurves of hot Jupiters. We demonstrate that the change from an optical lightcurve dominated by thermal emission to one dominated by scattering (reflection) naturally explains the observed trend from negative to positive offset. For the cool planets the presence of an asymmetry in the Kepler lightcurve is a telltale sign of the cloud composition, because each cloud species can produce an offset only over a narrow range of effective temperatures. By comparing our models and the observations, we show that the cloud composition of hot Jupiters likely varies with equilibrium temperature. We suggest that a transition occurs between silicate and manganese sulfide clouds at a temperature near 1600K, analogous to the L/T transition on brown dwarfs. The cold trapping of cloud species below the photosphere naturally produces such a transition and predicts similar transitions for other condensates, including TiO. We predict that most hot Jupiters should have cloudy nightsides, that partial cloudiness should be common at the limb and that the dayside hot spot should often be cloud-free.

  13. Transitions in the Cloud Composition of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Parmentier, Vivien; Fortney, Jonathan J.; Showman, Adam P.; Morley, Caroline; Marley, Mark S.

    2016-09-01

    Over a large range of equilibrium temperatures, clouds shape the transmission spectrum of hot Jupiter atmospheres, yet their composition remains unknown. Recent observations show that the Kepler light curves of some hot Jupiters are asymmetric: for the hottest planets, the light curve peaks before secondary eclipse, whereas for planets cooler than ˜1900 K, it peaks after secondary eclipse. We use the thermal structure from 3D global circulation models to determine the expected cloud distribution and Kepler light curves of hot Jupiters. We demonstrate that the change from an optical light curve dominated by thermal emission to one dominated by scattering (reflection) naturally explains the observed trend from negative to positive offset. For the cool planets the presence of an asymmetry in the Kepler light curve is a telltale sign of the cloud composition, because each cloud species can produce an offset only over a narrow range of effective temperatures. By comparing our models and the observations, we show that the cloud composition of hot Jupiters likely varies with equilibrium temperature. We suggest that a transition occurs between silicate and manganese sulfide clouds at a temperature near 1600 K, analogous to the L/T transition on brown dwarfs. The cold trapping of cloud species below the photosphere naturally produces such a transition and predicts similar transitions for other condensates, including TiO. We predict that most hot Jupiters should have cloudy nightsides, that partial cloudiness should be common at the limb, and that the dayside hot spot should often be cloud-free.

  14. The Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Grammier, Richard S.

    2006-01-01

    Origin: Determine O/H ratio (water abundance) and constrain core mass to decide among alternative theories of origin. Interior: Understand Jupiter's interior structure and dynamical properties by mapping its gravitational and magnetic fields Atmosphere: Map variations in atmospheric composition, temperature, cloud opacity and dynamics to depths greater than 100 bars at all latitudes. Magnetosphere: Characterize and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras.

  15. Jupiter Eruptions Captured in Infrared

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This infrared image shows two bright plume eruptions obtained by the NASA Infrared Telescope Facility on April 5, 2007.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vigorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  16. Ulysses dust measurements near Jupiter.

    PubMed

    Grün, E; Zook, H A; Baguhl, M; Fechtig, H; Hanner, M S; Kissel, J; Lindblad, B A; Linkert, D; Linkert, G; Mann, I B

    1992-09-11

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  17. Galileo and Cassini at Jupiter

    NASA Astrophysics Data System (ADS)

    Bindschadler, D. L.; Johnson, T. V.; Hansen, C. H.; Matson, D. L.; Lebreton, J.-P.; Bolton, S. J.; Spilker, L. J.

    2000-12-01

    Galileo's 29th orbit of Jupiter coincides with the period of time that the Cassini spacecraft will be making Jupiter system observations during its flyby on the way to Saturn. Galileo science objectives for this period include coordinated studies of the system, specific targeted events, and Galileo's first detailed study of Ganymede in eclipse. Systematic study of the dusk region of the Jovian magnetosphere has already begun, as Galileo exited the magnetosphere after the Ganymede 28 encounter and entered the solar wind for the first time since 1996. It will re-enter the magnetosphere as Cassini approaches in the Fall of 2000 and be near periapsis with Jupiter at the time of Cassini closest approach. Combining information from both Galileo and Cassini will allow a detailed study of the effects of the solar wind on the magnetosphere for the first time. In addition, the changing geometry of the two spacecraft creates opportunities for coordinated observations of specific phenomena. One example is the measurement of Jupiter dust stream particles with the dust investigations on both spacecraft. Another is observation of an Io eclipse from two different viewpoints and with complementary wavelengths, time and spatial resolution. Finally, the Ganymede 29 encounter will be a unique one, since Ganymede is in Jupiter's shadow at the time of closest approach. Observations will include attempts to determine the geometry of auroral emissions and their relation to Ganymede's magnetosphere and its interaction with Jupiter's environment. This work was supported under NASA's contract with Caltech/Jet Propulsion Laboratory.

  18. Japanese mission plan for Jupiter system: The Jupiter magnetospheric orbiter and the Trojan asteroid explorer

    NASA Astrophysics Data System (ADS)

    Sasaki, S.; Fujimoto, M.; Yano, H.; Takashima, T.; Kasaba, Y.; Takahashi, Y.; Kimura, J.; Funase, R.; Mori, O.; Tsuda, Y.; Campagnola, S.; Kawakatsu, Y.

    2011-10-01

    In the future Jupiter system study, Coordinated observation of Jovian magnetosphere is one of the important targets of the mission in addition to icy satellites, atmosphere, and interior of Jupiter. JAXA will take a role on the magnetosphere spinner JMO (Jupiter Magnetospheric Orbiter), in addition to JGO (Jupiter Ganymede Orbiter) by ESA and JEO (Jupiter Europa Orbiter) by NASA. We will combine JMO with a proposed solar sail mission of JAXA for Jupiter and one of Trojan asteroids. Since Trojan asteroids could be representing raw solid materials of Jupiter or at least outer solar system bodies, involvement of Trojan observation should enhance the quality of Jupiter system exploration.

  19. Zonal Flow and Vortices in Anelastic Deep Convection Models of Jupiter and Saturn With Shallow Stable Stratification

    NASA Astrophysics Data System (ADS)

    Heimpel, M. H.; Wicht, J.; Gastine, T.

    2015-12-01

    Planetary jet streams and vortices have been studied for over 350 years, yet their origin and dynamics are still vigorously debated. On both Jupiter and Saturn zonal flow consists of equatorial superrotation and alternating East-West jets at higher latitude. On Jupiter, numerous vortices, the vast majority anticyclones, occur with various sizes and lifetimes, interacting strongly with the zonal flow. Saturn's vortices and jets are also clearly coupled, and its North and South polar vortices are cyclonic. Models of giant planet atmospheres have generally been of two classes. Shallow flow models produce jets and vortices from 2D turbulence in a very thin spherical layer, but require special conditions to reproduce observed equatorial superrotation. In contrast, deep convection models generically reproduce equatorial superrotation, but typically lack coherent vortices, which do not survive the formation of jets. Here, we combine elements of both approaches using a 3D spherical shell compressible fluid numerical model, driven by convection at depth, but grading to a stably stratified shallow layer. In typical model simulations convective plumes rising from the deep interior impinge on the stably stratified layer, diverge near the outer spherical surface, and efficiently create the dominant anticyclones, which are shielded by downwelling cyclonic rings and filaments. These results may explain the dominance of anticyclones and the flow structure of small and medium sized anticyclonic ovals on Jupiter. The largest of our model vortices form in westward anticyclonic shear nearest the equatorial jet, similar to Saturn's "storm alley" and Jupiter's Great Red Spot. We also explore conditions under which cyclones, including polar cyclones like those on Saturn, may form.

  20. The dusty ballerina skirt of Jupiter

    NASA Astrophysics Data System (ADS)

    Horanyi, M.; Morfill, G.; Gruen, E.

    1993-12-01

    We suggest a model to explain the unexpected recurrent dust events that were observed during the Jupiter encounter by the dust detector on board the Ulysses spacecraft. This model is based dust-magnetosphere interactions. Dust particles inside the Jovian magnetosphere collect electrostatic charges and their interaction with the magnetic and electric fields can lead to energization and subsequent ejection. We discuss the dusty regions (ring/halo, `gossamer' ring) and also Io as potential sources for the Ulysses events. This model favors Io as a source. The mass and velocity range of the escaping particles are compatible with the observations, and we also suggest internal periodicities to explain the recurrent nature of the Ulysses dust events.

  1. Hubble Images Reveal Jupiter's Auroras

    NASA Technical Reports Server (NTRS)

    1996-01-01

    These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.

    The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.

    The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.

    The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.

    The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.

    This image and

  2. An auroral flare at Jupiter.

    PubMed

    Waite, J H; Gladstone, G R; Lewis, W S; Goldstein, R; McComas, D J; Riley, P; Walker, R J; Robertson, P; Desai, S; Clarke, J T; Young, D T

    2001-04-12

    Jupiter's aurora is the most powerful in the Solar System. It is powered largely by energy extracted from planetary rotation, although there seems also to be a contribution from the solar wind. This contrasts with Earth's aurora, which is generated through the interaction of the solar wind with the magnetosphere. The major features of Jupiter's aurora (based on far-ultraviolet, near-infrared and visible-wavelength observations) include a main oval that generally corotates with the planet and a region of patchy, diffuse emission inside the oval on Jupiter's dusk side. Here we report the discovery of a rapidly evolving, very bright and localized emission poleward of the northern main oval, in a region connected magnetically to Jupiter's outer magnetosphere. The intensity of the emission increased by a factor of 30 within 70 s, and then decreased on a similar timescale, all captured during a single four-minute exposure. This type of flaring emission has not previously been reported for Jupiter (similar, but smaller, transient events have been observed at Earth), and it may be related directly to changes in the solar wind.

  3. On Approach: Jupiter and Io

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of On Approach: Jupiter and Io

    This sequence of images was taken on Jan. 8, 2007, with the New Horizons Long Range Reconnaissance Imager (LORRI), while the spacecraft was about 81 million kilometers (about 50 million miles) from Jupiter. Jupiter's volcanic moon Io is to the right; the planet's Great Red Spot is also visible. The image was one of 11 taken during the Jan. 8 approach sequence, which signaled the opening of the New Horizons Jupiter encounter.

    Even in these early approach images, Jupiter shows different face than what previous visiting spacecraft -- such as Voyager 1, Galileo and Cassini -- have seen. Regions around the equator and in the southern tropical latitudes seem remarkably calm, even in the typically turbulent 'wake' behind the Great Red Spot.

    The New Horizons science team will scrutinize these major meteorological features -- including the unexpectedly calm regions -- to understand the diverse variety of dynamical processes on the solar system's largest planet. These include the newly formed Little Red Spot, the Great Red Spot and a variety of zonal features.

  4. Scientists Revise Thinking on Comets, Planet Jupiter

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses scientific information obtained from Pioneer 10's Jupiter flyby and the comet Kohoutek's first trip around the sun, including the high hydrogen emission of Jupiter's principal moon, Io. (CC)

  5. ECCENTRIC JUPITERS VIA DISK–PLANET INTERACTIONS

    SciTech Connect

    Duffell, Paul C.; Chiang, Eugene E-mail: echiang@astro.berkeley.edu

    2015-10-20

    Numerical hydrodynamics calculations are performed to determine the conditions under which giant planet eccentricities can be excited by parent gas disks. Unlike in other studies, Jupiter-mass planets are found to have their eccentricities amplified—provided their orbits start off as eccentric. We disentangle the web of co-rotation, co-orbital, and external resonances to show that this finite-amplitude instability is consistent with that predicted analytically. Ellipticities can grow until they reach of order of the disk's aspect ratio, beyond which the external Lindblad resonances that excite eccentricity are weakened by the planet's increasingly supersonic epicyclic motion. Forcing the planet to still larger eccentricities causes catastrophic eccentricity damping as the planet collides into gap walls. For standard parameters, the range of eccentricities for instability is modest; the threshold eccentricity for growth (∼0.04) is not much smaller than the final eccentricity to which orbits grow (∼0.07). If this threshold eccentricity can be lowered (perhaps by non-barotropic effects), and if the eccentricity driving documented here survives in 3D, it may robustly explain the low-to-moderate eccentricities ≲0.1 exhibited by many giant planets (including Jupiter and Saturn), especially those without planetary or stellar companions.

  6. Jupiter, Tether, and Lenz's Law

    NASA Technical Reports Server (NTRS)

    Lee, Russell

    1999-01-01

    Jupiter has a large, complex, and intense magnetic field that is thought to arise from electrical currents in the rapidly spinning metallic hydrogen interior. The strong magnetic field can induce currents when the conductive tether is directed toward or away from Jupiter. The currents can be stored and used for both propulsion and power generation. Therefore, our spacecraft might be able to visit several Jovian moons or maintain in the orbit around Jupiter. In our future space traveling, we also can use this technical skill to travel to other planets without any fuel. First-year physics textbooks describe Lenz's Law in which current is induced in a conductor moving through a stationary magnetic field. A demonstration of induced current in a stationary conductor and moving magnetic field is described, which may have space-tether application.

  7. Gravitational energy sources in Jupiter

    NASA Technical Reports Server (NTRS)

    Flasar, F. M.

    1973-01-01

    Gravitational sources of the intrinsic luminosity of Jupiter are examined in the context of current hydrogen-helium models. When no gravitational separation of matter occurs, the amount of heat which can be released over the remaining lifetime of the planet is necessarily limited by the size of its existing reservoir of thermal energy. This conclusion rests only on the assumption that its interior is relatively cold and degenerate. If gravitational unmixing occurs, the size of the thermal reservoir does not necessarily limit the heat output. If core formation occurs, for example, then the size of the core formed will be a limiting factor. The energy released with the formation of a helium core is computed for Jupiter. A core growth rate, averaged over several billion years, of 20 trillionths of Jupiter's mass per year is required if gravitational separation is to play a significant role in the thermal evolution.

  8. Arsine in Saturn and Jupiter

    NASA Technical Reports Server (NTRS)

    Noll, Keith S.; Geballe, T. R.; Knacke, R. F.

    1989-01-01

    New spectra of Saturn and Jupiter are reported that show a prominent, heretofore unidentified absorption near 2126/cm. The observation is interpreted as unambiguous evidence for the presence of arsine, AsH3. The abundance of AsH3 appears to be almost a factor of two higher in Saturn than in Jupiter. The observed enrichments are consistent with the core instability model for the formation of giant planets. Models of arsenic chemistry that predict strong depletions of AsH3 at temperatures below 370 K are not consistent with the observations, suggesting that vertical convection or perhaps some other mechanism inhibits depletion. Arsenic is the first new element identified in a planetary atmosphere since germanium was found in Jupiter a decade ago.

  9. A New Year for Jupiter and Io

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Galilean satellite Io floats above the cloudtops of Jupiter in this image captured on the dawn of the new millennium, January 1, 2001 10:00 UTC (spacecraft time), two days after Cassini's closest approach. The image is deceiving: there are 350,000 kilometers -- roughly 2.5 Jupiters -- between Io and Jupiter's clouds. Io is the size of our Moon, and Jupiter is very big.

  10. Discovery of a new Jupiter satellite

    NASA Technical Reports Server (NTRS)

    Jewitt, D. C.; Danielson, G. E.; Synnott, S. P.

    1979-01-01

    During detailed analysis of Voyager 2 pictures of the Jupiter ring, a starlike object was identified in the plane of the ring. The same object was subsequently found on a higher-resolution frame and proved to be a satellite of Jupiter. This satellite has a circular orbit whose radius is 1.8 Jupiter radii, a period of 7 hours and 8 minutes, and a diameter of less than 40 kilometers. It is located at the outer edge of the Jupiter ring.

  11. Spin scan imaging at Jupiter

    NASA Technical Reports Server (NTRS)

    Sinclair, K. F.

    1973-01-01

    The general feasibility of spin scan imaging from spinning platforms in outer planet orbiters was investigated. The study was limited to consideration of a typical orbiter mission to Jupiter with an orbit designed to provide repetitive close approaches to the Galilean satellites. Discussed are: (1) data requirements for imaging experiments at Jupiter and its satellites; (2) spin scan camera and baseline camera selection; and (3) operational considerations bearing on imager performance. A physical camera model including relationships identifying the supporting requirements was developed and used to determine the characteristics of the baseline camera.

  12. Jupiter - First stop on Voyager's grand tour

    NASA Technical Reports Server (NTRS)

    Morrison, David

    1989-01-01

    The findings concerning Jupiter that were made by the Voyager missions are briefly reviewed. The ring and three new moons around Jupiter, the live volcanoes on Io, and atmospheric phenomena on Jupiter which were observed by Voyager 1 are described. The discoveries regarding Callisto and Europa made by Voyager 2 are briefly summarized.

  13. A New Model for Turbulent Heating of Jupiter's Magnetosphere

    NASA Astrophysics Data System (ADS)

    Kaminker, V. M.; Ng, C. S.; Delamere, P. A.; Neupane, B. R.

    2015-12-01

    The ion temperature of the magnetosphere of Jupiter derived from Galileo PLS data was observed to increase by about an order of magnitude from 10 to 40 Jupiter radii. This suggests presence of heating sources that counteract adiabatic cooling effect of expanding plasma. There have been different models trying to explain such observation using different heating mechanisms, including a heating model based on magnetohydrodynamic (MHD) turbulence [Saur, Astrophys. J. Lett., 602, L137, 2004]. We revisit that model, which is based on flux tube diffusion, and find that it is not adequate in explaining the heating. To account for possible heating by turbulence, we apply another turbulence heating model based on convection, which is commonly used in modeling solar wind heating. Based on analysis of Galileo magnetometer data, we find that observed MHD turbulence could potentially provide the required heating based on this model. This work is supported by a NASA grant (NNX14AM27G).

  14. Magnetic Reconnection and Associated Transient Phenomena Within the Magnetospheres of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Louarn, Philippe; Andre, Nicolas; Jackman, Caitriona M.; Kasahara, Satoshi; Kronberg, Elena A.; Vogt, Marissa F.

    2015-04-01

    We review in situ observations made in Jupiter and Saturn's magnetosphere that illustrate the possible roles of magnetic reconnection in rapidly-rotating magnetospheres. In the Earth's solar wind-driven magnetosphere, the magnetospheric convection is classically described as a cycle of dayside opening and tail closing reconnection (the Dungey cycle). For the rapidly-rotating Jovian and Kronian magnetospheres, heavily populated by internal plasma sources, the classical concept (the Vasyliunas cycle) is that the magnetic reconnection plays a key role in the final stage of the radial plasma transport across the disk. By cutting and closing flux tubes that have been elongated by the rotational stress, the reconnection process would lead to the formation of plasmoids that propagate down the tail, contributing to the final evacuation of the internally produced plasma and allowing the return of the magnetic flux toward the planet. This process has been studied by inspecting possible `local' signatures of the reconnection, as magnetic field reversals, plasma flow anisotropies, energetic particle bursts, and more global consequences on the magnetospheric activity. The investigations made at Jupiter support the concept of an `average' X-line, extended in the dawn/dusk direction and located at 90-120 Jovian radius (RJ) on the night side. The existence of a similar average X-line has not yet been established at Saturn, perhaps by lack of statistics. Both at Jupiter and Saturn, the reconfiguration signatures are consistent with magnetospheric dipolarizations and formation of plasmoids and flux ropes. In several cases, the reconfigurations also appear to be closely associated with large scale activations of the magnetosphere, seen from the radio and auroral emissions. Nevertheless, the statistical study also suggests that the reconnection events and the associated plasmoids are not frequent enough to explain a plasma evacuation that matches the mass input rate from the

  15. The Voyager Spacecraft. [Jupiter-Saturn mission investigations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The configuration of the Voyager spacecraft is described as well as the subsystems for power, temperature control, attitude control, and propulsion. Major features of Jupiter and Saturn including their atmospheres, surfaces, and natural satellites are discussed. The 13 onboard experiments and their scientific objectives are explained. Other aspects covered include tracking, data acquisition, and the mission control and computing center. Members of the Voyager team and subcontractors are listed.

  16. Hot Jupiters Aren't As Lonely As We Thought

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    The Friends of Hot Jupiters (FOHJ) project is a systematic search for planetary- and stellar-mass companions in systems that have known hot Jupiters short-period, gas-giant planets. This survey has discovered that many more hot Jupiters may have companions than originally believed.Missing FriendsFOHJ was begun with the goal of better understanding the systems that host hot Jupiters, in order to settle several longstanding issues.The first problem was one of observational statistics. We know that roughly half of the Sun-like stars nearby are in binary systems, yet weve only discovered a handful of hot Jupiters around binaries. Are binary systems less likely to host hot Jupiters? Or have we just missed the binary companions in the hot-Jupiter-hosting systems weve seen so far?An additional issue relates to formation mechanisms. Hot Jupiters probably migrated inward from where they formed out beyond the ice lines in protoplanetary disks but how?This median-stacked image, obtained with adaptive optics, shows one of the newly-discovered stellar companions to a star hosting a hot Jupiter. The projected separation is ~180 AU. [Ngo et al. 2015]Observations reveal two populations of hot Jupiters: those with circular orbits aligned with their hosts spins, and those with eccentric, misaligned orbits. The former population support a migration model dominated by local planet-disk interactions, whereas the latter population suggest the hot Jupiters migrated through dynamical interactions with distant companions. A careful determination of the companion rate in hot-Jupiter-hosting systems could help establish the ability of these two models to explain the observed populations.Search for CompanionsThe FOHJ project began in 2012 and studied 51 systems hosting known, transiting hot Jupiters with roughly half on circular, aligned orbits and half on eccentric, misaligned orbits. The survey consisted of three different, complementary components:Study 1Lead author: Heather Knutson

  17. Heavy ions in Jupiter's environment

    NASA Technical Reports Server (NTRS)

    Brown, R. A.

    1980-01-01

    The extended atmosphere of the Jupiter system consists of atoms and ions of heavy elements. This material originates on the satellite Io. Energy is lost from the thermal plasma in collisionally excited optical and ultraviolet emission. The juxtaposition of Earth and spacecraft measurements provide insight concerning the underlying processes of particle transport and energy supply.

  18. Origins of Hot Jupiters, Revisited

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter; Laughlin, Greg

    2016-05-01

    Hot Jupiters, giant extrasolar planets with orbital periods less than ~10 days, have long been thought to form at large radial distances (a > 2AU) in protoplanetary disks, only to subsequently experience large-scale inward migration to the small orbital radii at which they are observed. Here, we propose that a substantial fraction of the hot Jupiter population forms in situ, with the Galactically prevalent short-period super-Earths acting as the source population. Our calculations suggest that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated for solid cores of 10-20 Earth masses, in line with the conventional picture of core-nucleated accretion. The planetary conglomeration process, coupled with subsequent gravitational contraction and spin down of the host star, drives sweeping secular resonances through the system, increasing the mutual inclinations of exterior, low-mass companions to hot Jupiters. Accordingly, this formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional non-transiting planets, reminiscent of those observed in large numbers by NASA’s Kepler Mission and Doppler velocity surveys. High-precision radial velocity monitoring provides the best prospect for their detection.

  19. Origins of Hot Jupiters, Revisited

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter; Laughlin, Greg

    2015-12-01

    Hot Jupiters, giant extrasolar planets with orbital periods less than ~10 days, have long been thought to form at large radial distances (a > 2AU) in protostellar disks, only to subsequently experience large-scale inward migration to the small orbital radii at which they are observed. Here, we propose that a substantial fraction of the hot Jupiter population forms in situ, with the Galactically prevalent short-period super-Earths acting as the source population. Our calculations suggest that under conditions appropriate to the inner regions of protostellar disks, rapid gas accretion can be initiated for solid cores of 10-20 Earth masses, in line with the conventional picture of core-nucleated accretion. This formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional planets, reminiscent of those observed in large numbers by NASA’s Kepler Mission and Doppler velocity surveys. However, dynamical interactions during the early stages of planetary systems' evolutionary lifetimes tend to increase the mutual inclinations of exterior, low-mass companions to hot Jupiters, making transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  20. Alice Views Jupiter and Io

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This graphic illustrates the pointing and shows the data from one of many observations made by the New Horizons Alice ultraviolet spectrometer (UVS) instrument during the Pluto-bound spacecraft's recent encounter with Jupiter. The red lines in the graphic show the scale, orientation, and position of the combined 'box and slot' field of view of the Alice UVS during this observation.

    The positions of Jupiter's volcanic moon, Io, the torus of ionized gas from Io, and Jupiter are shown relative to the Alice field of view. Like a prism, the spectrometer separates light from these targets into its constituent wavelengths.

    Io's volcanoes produce an extremely tenuous atmosphere made up primarily of sulfur dioxide gas, which, in the harsh plasma environment at Io, breaks down into its component sulfur and oxygen atoms. Alice observed the auroral glow from these atoms in Io's atmosphere and their ionized counterparts in the Io torus.

    Io's dayside is deliberately overexposed to bring out faint details in the plumes and on the moon's night side. The continuing eruption of the volcano Tvashtar, at the 1 o'clock position, produces an enormous plume roughly 330 kilometers (200 miles) high, which is illuminated both by sunlight and 'Jupiter light.'

  1. Voyager to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Voyager mission to explore planets of the outer solar system is summarized. The mission schedule and profiles for encounters with Jupiter and Saturn, and possibly with Uranus and Pluto are included along with a description of the spacecraft and its trajectories. Scientific investigations to be made and the instruments carried are also discussed.

  2. SUPER-ECCENTRIC MIGRATING JUPITERS

    SciTech Connect

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott

    2012-05-10

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  3. Jupiter: Cosmic Jekyll and Hyde.

    PubMed

    Grazier, Kevin R

    2016-01-01

    It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to

  4. Jupiter's High-Altitude Clouds

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this incredibly detailed picture of Jupiter's high-altitude clouds starting at 06:00 Universal Time on February 28, 2007, when the spacecraft was only 2.3 million kilometers (1.4 million miles) from the solar system's largest planet. Features as small as 50 kilometers (30 miles) are visible. The image was taken through a narrow filter centered on a methane absorption band near 890 nanometers, a considerably redder wavelength than what the eye can see. Images taken through this filter preferentially pick out clouds that are relatively high in the sky of this gas giant planet because sunlight at the wavelengths transmitted by the filter is completely absorbed by the methane gas that permeates Jupiter's atmosphere before it can reach the lower clouds.

    The image reveals a range of diverse features. The south pole is capped with a haze of small particles probably created by the precipitation of charged particles into the polar regions during auroral activity. Just north of the cap is a well-formed anticyclonic vortex with rising white thunderheads at its core. Slightly north of the vortex are the tendrils of some rather disorganized storms and more pinpoint-like thunderheads. The dark 'measles' that appear a bit farther north are actually cloud-free regions where light is completely absorbed by the methane gas and essentially disappears from view. The wind action considerably picks up in the equatorial regions where giant plumes are stretched into a long wave pattern. Proceeding north of the equator, cirrus-like clouds are shredded by winds reaching speeds of up to 400 miles per hour, and more pinpoint-like thunderheads are visible. Although some of the famous belt and zone structure of Jupiter's atmosphere is washed out when viewed at this wavelength, the relatively thin North Temperate Belt shows up quite nicely, as does a series of waves just north of the belt. The north polar region of

  5. Jupiter: Cosmic Jekyll and Hyde.

    PubMed

    Grazier, Kevin R

    2016-01-01

    It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to

  6. Featured Image: Mapping Jupiter with Hubble

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-07-01

    Zonal wind profile for Jupiter, describing the speed and direction of its winds at each latitude. [Simon et al. 2015]This global map of Jupiters surface (click for the full view!) was generated by the Hubble Outer Planet Atmospheres Legacy (OPAL) program, which aims to createnew yearly global maps for each of the outer planets. Presented in a study led by Amy Simon (NASA Goddard Space Flight Center), the map above is the first generated for Jupiter in the first year of the OPAL campaign. It provides a detailed look at Jupiters atmospheric structure including the Great Red Spot and allowed the authors to measure the speed and direction of the wind across Jupiters latitudes, constructing an updated zonal wind profile for Jupiter.In contrast to this study, the Juno mission (which will be captured into Jupiters orbit today after a 5-year journey to Jupiter!) will be focusing more on the features below Jupiters surface, studying its deep atmosphere and winds. Some of Junos primary goals are to learn about Jupiters composition, gravitational field, magnetic field, and polar magnetosphere. You can follow along with the NASATV livestream as Juno arrives at Jupiter tonight; orbit insertion coverage starts at 10:30 EDT.CitationAmy A. Simon et al 2015 ApJ 812 55. doi:10.1088/0004-637X/812/1/55

  7. Io in Front of Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter's four largest satellites, including Io, the golden ornament in front of Jupiter in this image from NASA's Cassini spacecraft, have fascinated Earthlings ever since Galileo Galilei discovered them in 1610 in one of his first astronomical uses of the telescope.

    Images from Cassini that will be released over the next several days capture each of the four Galilean satellites in their orbits around the giant planet.

    This true-color composite frame, made from narrow angle images taken on Dec. 12, 2000, captures Io and its shadow in transit against the disk of Jupiter. The distance of the spacecraft from Jupiter was 19.5 million kilometers (12.1 million miles). The image scale is 117 kilometers (73 miles) per pixel.

    The entire body of Io, about the size of Earth's Moon, is periodically flexed as it speeds around Jupiter and feels, as a result of its non-circular orbit, the periodically changing gravitational pull of the planet. The heat arising in Io's interior from this continual flexure makes it the most volcanically active body in the solar system, with more than 100 active volcanoes. The white and reddish colors on its surface are due to the presence of different sulfurous materials. The black areas are silicate rocks.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  8. What do the compositions of the regular satellites of Jupiter and Saturn tell us?

    NASA Astrophysics Data System (ADS)

    Mosqueira, I.; Podolak, M.

    2012-12-01

    Models for the formation of the regular satellites of Jupiter and Saturn are hampered by our lack of understanding of the turbulent state of the subnebula and the gas-inflow rate [1]. Fortunately, it is possible to construct regular satellite formation models that are not dependent on specific choices for these parameters [2,3]. These two approaches treat planetesimal dynamics explicitly (which is a model requirement [1]), and also account for the angular momentum budget of the regular satellites. The inner satellites of Jupiter, Io and Europa, are depleted of volatiles either due to the temperature gradient in the subnebula [4,5], collisional processes involving differentiated objects [6], and/or the Laplace resonance. The observed densities of the Saturnian regular satellites are not compatible with solar compositions [7]. The inner satellites of Saturn (inside of Titan) include a stochastic compositional component (e.g., Tethys vs. Enceladus) due to collisional processes deep in the kronian gravitational-potential well; however, such an argument can not be applied to faraway and isolated Iapetus. ([8] consider a collisional scattering origin for Iapetus, but we favor the model we present here.) The bulk compositional and size similarities between Ganymede, Callisto and Titan argue strongly in favor of non-stochastic processes for these satellites. Therefore, the non-stochastic masses and densities of the large, outer regular satellites of Jupiter and Saturn (Ganymede, Callisto, Titan and Iapetus) provide the most directly useful constraints for satellite formation models. Observations indicate that Kuiper Belt Objects (KBOs) are of different composition than the regular satellites of Jupiter and Saturn. The simplest explanation of the observations is that the subnebulae of these giant planets are enriched in water-ice compared to the outer solar nebula [7]. The contrast between icy Iapetus and rocky Phoebe reinforces the interpretation of Phoebe as a moon

  9. Jupiter Polar Winds Movie Blowup

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Persistent polar storms and zonal winds on Jupiter can be seen in this magnified quadrant from a movie projecting images from NASA's Cassini spacecraft as if the viewer were looking down at Jupiter's north pole and the planet were flattened.

    The sequence covers 70 days, from October 1 to December 9, 2000. Cassini's narrow-angle camera captured the images of Jupiter's atmosphere in the near-infrared region of the spectrum.

    Like the accompanying full-circle movie of polar winds, this zoomed-inversion shows that the polar region has coherent flows, despite its chaotic, mottled appearance. There are thousands of spots, each an active storm similar in size to the largest storms on Earth. The spots occasionally change latitude or merge with each other, but usually they last for the entire 70 days. Until now, the lifetime of those storms was unknown.

    The mystery of Jupiter's weather is why the storms last so long. Storms on Earth last for a week before they break up and are replaced by other storms. This movie heightens the mystery because it shows long-lived storms at the highest latitudes, where the weather patterns are more disorganized than at low latitudes.

    Cassini collected images of Jupiter for months before and after it passed the planet on December 30, 2000. Six images or more of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire sequence was repeated generally every other Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours.

    The images used for the movie shown here were taken every 20 hours through a filter centered at a wavelength of 756 nanometers, where there are almost no absorptions in the planet's atmosphere. Images from each rotation were assembled first into a cylindrical map. The 84 resulting cylindrical maps, spanning 70 Earth days or 168 Jupiter rotations, were transformed to polar stereographic

  10. High Latitude Mottling on Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The familiar banded appearance of Jupiter at low and middle latitudes gradually gives way to a more mottled appearance at high latitudes in this striking true color image taken Dec. 13, 2000, by NASA's Cassini spacecraft.

    The intricate structures seen in the polar region are clouds of different chemical composition, height and thickness. Clouds are organized by winds, and the mottled appearance in the polar regions suggests more vortex-type motion and winds of less vigor at higher latitudes.

    The cause of this difference is not understood. One possible contributor is that the horizontal component of the Coriolis force, which arises from the planet's rotation and is responsible for curving the trajectories of ocean currents and winds on Earth, has its greatest effect at high latitudes and vanishes at the equator. This tends to create small, intense vortices at high latitudes on Jupiter. Another possibility may lie in that fact that Jupiter overall emits nearly as much of its own heat as it absorbs from the Sun, and this internal heat flux is very likely greater at the poles. This condition could lead to enhanced convection at the poles and more vortex-type structures. Further analysis of Cassini images, including analysis of sequences taken over a span of time, should help us understand the cause of equator-to-pole differences in cloud organization and evolution.

    By the time this picture was taken, Cassini had reached close enough to Jupiter to allow the spacecraft to return images with more detail than what's possible with the planetary camera on NASA's Earth-orbiting Hubble Space Telescope. The resolution here is 114 kilometers (71 miles) per pixel. This contrast-enhanced, edge-sharpened frame was composited from images take at different wavelengths with Cassini's narrow-angle camera, from a distance of 19 million kilometers (11.8 million miles). The spacecraft was in almost a direct line between the Sun and Jupiter, so the solar illumination on

  11. 70 Days of Jupiter Winds

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This global movie of 70 days of Jupiter's cloud movements photographed by NASA's Cassini spacecraft shows that zones of eastward and westward winds cover the planet virtually from pole to pole.

    Cassini's narrow-angle camera captured the images of Jupiter's atmosphere from October 1 to December 9, 2000, in the near-infrared region of the spectrum. The view here is a cylindrical projection centered in the planet's equator.

    The movie allows tracking of individual storms' movements in the familiar zonal bands of the lower latitudes, in the swirling turbulence around the Great Red Spot and in the high latitudes where still images show chaotic mottling instead of stripes.

    Cassini collected images of Jupiter for months before and after it passed the planet on December 30, 2000. Six or more images of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire sequence was repeated generally every other Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours.

    The images used for the movie shown here were taken every 20 hours through a filter centered at a wavelength of 756 nanometers, where there are almost no absorptions in the planet's atmosphere. Six images covering each rotation were mosaiced together to form a cylindrical map extending from 75 degrees north to 75 degrees south in latitude and covering 360 degrees in longitude. The movie consists of 84 such maps, spanning 70Earth days in time or 168 Jupiter rotations.

    For more information, see the Cassini Project home page, http://www.jpl.nasa.gov/cassini/ and the Cassini Imaging Team home page, http://ciclops.lpl.arizona.edu/ciclops/ .

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of

  12. Jupiter in Color, by Cassini

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This color image of Jupiter was taken by the camera onboard NASA's Cassini spacecraft when it was 81.3 million kilometers (50.5 million miles) from the planet. It is composed of images taken in the blue, green, and red regions of the spectrum and is therefore close to the true color of Jupiter that one would see through an Earth-based telescope.

    The image is remarkably similar to images taken by NASA's Voyager 1 and 2 spacecraft more than 21 years ago, illustrating the stability of Jupiter's weather patterns. The parallel dark and bright bands and many other large-scale features are quasi-permanent structures that survive despite the intense small-scale activity ongoing in the atmosphere. The longevity of the large-scale features is an intrinsic property of the atmospheric flows on a gaseous planet such as Jupiter, with no solid surface. Smaller features, such as those in the dark bands north and south of the equator, are observed to form and disappear in a few days.

    Everything visible on the planet is a cloud. Unlike Earth, where only water condenses to form clouds, Jupiter has several cloud-forming substances in its atmosphere. The updrafts and downdrafts bring different mixtures of these substances up from below, leading to clouds of different colors. The bluish features just north of the equator are regions of reduced cloud cover, similar to the place where the Galileo atmospheric probe entered in 1995. They are called 'hot spots' because the reduced cloud cover allows heat to escape from warmer, deeper levels in the atmosphere.

    Jupiter's moon Europa is seen at the right, casting a shadow on the planet. Scientists believe Europa holds promise of a liquid ocean beneath its surface.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Cassini mission for NASA's Office of Space Science

  13. K2 Warm Jupiters with the LCOGT TECH collaboration

    NASA Astrophysics Data System (ADS)

    Shporer, Avi; Bayliss, Daniel; Cochran, William D.; Colón, Knicole D.; Dragomir, Diana; Palle, Enric; Potter, Stephen; Siverd, Robert; LCOGT TECH Collaboration

    2016-06-01

    Many transiting gas giant planets on short orbital periods (so called hot Jupiters) have larger radii than theoretically expected. Although several explanations have been proposed, none have completely solved this puzzle. As the number of known transiting planets grew a correlation was identified between gas giant radius and the stellar incident flux. Still, it is not clear whether this correlation is causation. Several questions remain and answering them will characterize in more detail this observed correlation and in turn the process responsible for the inflated radii, such as: Is the lack of inflated warm Jupiters a robust feature? What is the incident flux below which there are no inflated gas giants? How low in incident flux does this correlation stretch? These questions arise since there are only a small number of transiting gas giants with low incident flux, below about 108 erg/s/cm2, corresponding to orbital periods of about 10 days and longer for a Sun-like host star. Discovering and confirming more transiting warm Jupiters is the goal of this project, undertaken by the LCOGT Transiting Exoplanet CHaracterization (TECH) team. We are using K2 as our main source of transiting warm Jupiter candidates, with a few candidates discovered in each K2 campaign. LCOGT telescopes are being used for obtaining additional ground-based transit light curves, which are critical for confirming and refining the K2 transit ephemeris as outliers during ingress or egress of the few transit events observed by K2 can bias the measured ephemeris. Further ground-based follow-up data, including spectroscopy, radial velocities, and high angular resolution imaging, are obtained by facilities directly accessible by LCOGT TECH team members. In addition, once LCOGT’s Network of Robotic Echelle Spectrographs (NRES) are deployed in the near future they will allow obtaining spectroscopy and radial velocities with LCOGT facilities. On top of studying the inflated hot Jupiter conundrum

  14. MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS

    SciTech Connect

    Beauge, C.; Nesvorny, D.

    2012-06-01

    Doppler and transit observations of exoplanets show a pile-up of Jupiter-size planets in orbits with a 3 day period. A fraction of these hot Jupiters have retrograde orbits with respect to the parent star's rotation, as evidenced by the measurements of the Rossiter-McLaughlin effect. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization and migration of planets that evolved into highly eccentric orbits. We considered planetary systems having three and four planets initially placed in successive mean-motion resonances, although the angles were taken randomly to ensure orbital instability in short timescales. The simulations included the tidal and relativistic effects, and precession due to stellar oblateness. Our results show the formation of two distinct populations of hot Jupiters. The inner population (Population I) is characterized by semimajor axis a < 0.03 AU and mainly formed in the systems where no planetary ejections occurred. Our follow-up integrations showed that this population was transient, with most planets falling inside the Roche radius of the star in <1 Gyr. The outer population of hot Jupiters (Population II) formed in systems where at least one planet was ejected into interstellar space. This population survives the effects of tides over >1 Gyr and fits nicely the observed 3 day pile-up. A comparison between our three-planet and four-planet runs shows that the formation of hot Jupiters is more likely in systems with more initial planets. Due to the large-scale chaoticity that dominates the evolution, high eccentricities and/or high inclinations are generated mainly by close encounters between the planets and not by secular perturbations (Kozai or otherwise). The relative proportion of retrograde planets seems of be dependent on the stellar age. Both the distribution of almost aligned systems and the simulated 3 day pile-up also fit observations better in our four

  15. Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads:

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads: Galileo Probe descending into Jupiters Atmosphere shows heat shield separation with parachute deployed. (Ref. JPL P-19180)

  16. Map of Jupiter's moon Io

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-04-01

    Map of Jupiter's moon Io The first global geologic map of the Jovian satellite Io has been published by the U.S. Geological Survey (USGS), the agency announced on 19 March. “More than 130 years after the USGS first began producing quality geologic maps here on Earth, it is exciting to have the reach of our science extend across 400 million miles to this volcanically active moon of Jupiter,” said USGS director Marcia McNutt. “Somehow it makes the vast expanse of space seem less forbidding to know that similar geologic processes which have shaped our planet are active elsewhere.” The map illustrates the geologic character of the unique and active volcanoes on Io, a planetary body that has about 25 times more volcanic activity than Earth does, according to USGS.

  17. Cold Hole Over Jupiter's Pole

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.

    These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.

    The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.

    The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.

    The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.

    These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at

  18. Jupiter's Clouds: Structure and Composition.

    PubMed

    Lewis, J S; Prinn, R G

    1970-07-31

    Recent infrared radiometric observations of Jupiter have disclosed local temperatures in the North Equatorial Belt far in excess of those at the level of the solid ammonia clouds, and visual observations reveal an orange-brown coloration within this belt. We suggest that, in a multilayer cloud model, solar ultraviolet photolysis of hydrogen sulfide in regions where ammonia clouds are sparse or absent should lead to the production of substantial quantities of inorganic chromophores.

  19. First Evidence of Jupiter Ring

    NASA Technical Reports Server (NTRS)

    1979-01-01

    First evidence of a ring around the planet Jupiter is seen in this photograph taken by Voyager 1 on March 4, 1979. The multiple exposure of the extremely thin faint ring appears as a broad light band crossing the center of the picture. The edge of the ring is 1,212,000 km from the spacecraft and 57,000 km from the visible cloud deck of Jupiter. The background stars look like broken hair pins because of spacecraft motion during the 11 minute 12 second exposure. The wavy motion of the star trails is due to the ultra-slow natural oscillation of the spacecraft (with a period of 78 seconds). The black dots are geometric calibration points in the camera. The ring thickness is estimated to be 30 km or less. The photograph was part of a sequence planned to search for such rings in Jupiter's equatorial plane. The ring has been invisible from Earth because of its thinness and its transparency when viewed at any angle except straight on. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

  20. Ammonia Ice Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The top cloud layer on Jupiter is thought to consist of ammonia ice, but most of that ammonia 'hides' from spectrometers. It does not absorb light in the same way ammonia does. To many scientists, this implies that ammonia churned up from lower layers of the atmosphere 'ages' in some way after it condenses, possibly by being covered with a photochemically generated hydrocarbon mixture. The New Horizons Linear Etalon Imaging Spectral Array (LEISA), the half of the Ralph instrument that is able to 'see' in infrared wavelengths that are absorbed by ammonia ice, spotted these clouds and watched them evolve over five Jupiter days (about 40 Earth hours). In these images, spectroscopically identified fresh ammonia clouds are shown in bright blue. The largest cloud appeared as a localized source on day 1, intensified and broadened on day 2, became more diffuse on days 3 and 4, and disappeared on day 5. The diffusion seemed to follow the movement of a dark spot along the boundary of the oval region. Because the source of this ammonia lies deeper than the cloud, images like these can tell scientists much about the dynamics and heat conduction in Jupiter's lower atmosphere.

  1. Solar wind collimation of the Jupiter high velocity dust streams

    NASA Astrophysics Data System (ADS)

    Flandes, A.; Krueger, H.

    2006-12-01

    The dust bursts discovered by the Ulysses dust sensor when approaching Jupiter in 1992 were later confirmed as collimated streams of high velocity (~200 km/s) charged (~5V) dust grains escaping from Jupiter and dominated by the interplanetary Magnetic field (IMF). With Cassini, a similar phenomenon was observed in Saturn. It was demonstrated that the Jovian dust streams are closely related to the solar wind compressed regions, either Corotating interaction regions (CIRs) or Coronal mass ejections (CMEs) ¨Cto a minor extent-. Actually the dust streams seem ultimately to be generated by such events. This can be explained considering that dust grains are accelerated as they gain substantial energy while compressed at the forward and reverse shocks that bound or precede these solar wind regions.

  2. VLA Will Receive Galileo Probe Signals To Measure Jupiter's Winds

    NASA Astrophysics Data System (ADS)

    1995-11-01

    Socorro, NM -- When the Galileo Probe becomes the first spacecraft to enter the atmosphere of Jupiter on Dec. 7, a New Mexico radio telescope will be watching. In a technical feat thought impossible when Galileo was launched in 1989, the National Science Foundation's Very Large Array (VLA) will record the faint radio signal from the probe to help scientists measure the giant planet's winds. The VLA observations will dramatically improve estimates of Jupiter's wind speeds and complement other measurements studying the climate of Jupiter. The Galileo probe will transmit information to the main spacecraft as it descends toward a searing death under tremendous heat in Jupiter's lower atmosphere. The main spacecraft will later relay the probe's data to Earth. No Earth-based reception of the probe's radio signals was planned originally. The probe's antenna will be pointed at the main spacecraft, not the Earth. However, in 1991, Robert Preston and William Folkner of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, CA, were discussing Earth-based reception of data from a similar probe under design for a planned mission to Saturn. "I thought, why not do this for Galileo," Folkner said. "They were planning to build this capability into the spacecraft for Saturn," Folkner explained, "and they thought it couldn't be done with the Galileo spacecraft already enroute to Jupiter. I didn't know it couldn't be done, so I worked it out and found that we could do it." According to Preston and Folkner's calculations, the direct reception of the probe's signals by the VLA and a similar radio telescope in Australia will make the measurement of Jupiter's winds ten times more precise as long as the probe radio signal can be detected. In addition, the direct reception also greatly improves scientists' knowledge of the probe's position as it enters the Jovian atmosphere. This will allow more effective use of the measurements of the probe radio signal by the main spacecraft to determine

  3. Re-inflated Warm Jupiters around Red Giants: A New Test for Models of Hot Jupiter Inflation

    NASA Astrophysics Data System (ADS)

    Lopez, Eric D.; Jonathan, Fortney

    2015-12-01

    Ever since the discovery of the first transiting hot Jupiter, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of the hot Jupiter radius anomaly scales strongly with a planet’s level of irradiation and numerous models have since been developed to help explain these inflated radii. In general however, these models can be grouped into two broad categories: 1) models that directly inflate planetary radii by depositing a fraction of the incident irradiation in the convective interior and 2) models that simply slow a planet’s radiative cooling allowing it to retain more heat from formation and thereby delay contraction. Here we propose a new test to distinguish between these two classes of models, by examining the post-main sequence radius evolution of gas giants with moderate orbital periods of ~10-30 days. If hot Jupiter inflation actively deposits heat in a planets interior then current and upcoming transit surveys should uncover a new population of “re-inflated” gas giants around post main sequence stars.

  4. Jupiter C/Explorer 1 in Gantry

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Explorer 1 atop a Jupiter-C in gantry. Jupiter-C carrying the first American satellite, Explorer 1, was successfully launched on January 31, 1958. The Jupiter-C launch vehicle consisted of a modified version of the Redstone rocket's first stage and two upper stages of clustered Baby Sergeant rockets developed by the Jet Propulsion Laboratory and later designated as Juno boosters for space launches

  5. Re-inflated Warm Jupiters around Red Giants

    NASA Astrophysics Data System (ADS)

    Lopez, Eric D.; Fortney, Jonathan J.

    2016-02-01

    Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.

  6. Lacking "Lack": A Reply to Joldersma

    ERIC Educational Resources Information Center

    Marshall, James D.

    2007-01-01

    First I would like to thank Clarence Joldersma for his review of our "Poststructuralism, Philosophy, Pedagogy" (Marshall, 2004-PPP). In particular, I would thank him for his opening sentence: "[t]his book is a response to a lack." It is the notion of a lack, noted again later in his review, which I wish to take up mainly in this response. Rather…

  7. A Model of Jupiter's Decametric Radio Emissions as a Searchlight Beam

    NASA Astrophysics Data System (ADS)

    Imai, K.; Garcia, L.; Reyes, F.; Imai, M.; Thieman, J. R.

    It has long been recognized that there is a marked long-term periodic variation in Jupiter's integrated radio occurrence probability. The period of the variation is on the order of a decade. Carr et al. [1970] showed that such variations are closely correlated with Jovicentric declination of the Earth (DE). The range of the smoothed variation of DE is from approximately +3.3 to -3.3 degrees. This DE effect was extensively studied and confirmed by Garcia [1996]. It shows that the occurrence probability of the non-Io-A source is clearly controlled by DE at 18, 20, and 22 MHz during the 1957-1994 apparitions. We propose a new model to explain the DE effect. This new model shows that the beam structure of Jupiter radio emissions, which has been thought of like a hollow-cone, has a narrow beam like a searchlight, which can be explained by assuming that the three dimensional shape of the radio source expands along the line of the magnetic field. If we consider the sizes of the radio coherent region are 1000 m along Jupiter's magnetic field line and 200 m along the latitudinal direction, the equivalent beam pattern is 1 degree wide along Jupiter's magnetic field line and 5 degrees in latitude. As the searchlight beam is fixed with Jupiter's magnetic field, the pure geometrical effect of DE can be explained by this searchlight beam model.

  8. Juno at Jupiter: Mission and Science

    NASA Astrophysics Data System (ADS)

    Bolton, Scott

    2016-07-01

    The Juno mission is the second mission in NASA's New Frontiers program. Launched in August 2011, Juno arrives at Jupiter in July 2016. Juno science goals include the study of Jupiter's origin, interior structure, deep atmosphere, aurora and magnetosphere. Jupiter's formation is fundamental to the evolution of our solar system and to the distribution of volatiles early in the solar system's history. Juno's measurements of the abundance of Oxygen and Nitrogen in Jupiter's atmosphere, and the detailed maps of Jupiter's gravity and magnetic field structure will constrain theories of early planetary development. Juno's orbit around Jupiter is a polar elliptical orbit with perijove approximately 5000 km above the visible cloud tops. The payload consists of a set of microwave antennas for deep sounding, magnetometers, gravity radio science, low and high energy charged particle detectors, electric and magnetic field radio and plasma wave experiment, ultraviolet imaging spectrograph, infrared imager and a visible camera. The Juno design enables the first detailed investigation of Jupiter's interior structure, and deep atmosphere as well as the first in depth exploration of Jupiter's polar magnetosphere. The Juno mission design, science goals, and measurements related to the atmosphere of Jupiter will be presented.

  9. Probing Storm Activity on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Scientists assume Jupiter's clouds are composed primarily of ammonia, but only about 1% of the cloud area displays the characteristic spectral fingerprint of ammonia. This composite of infrared images taken by the New Horizons Linear Etalon Infrared Spectral Imager (LEISA) captures several eruptions of this relatively rare breed of ammonia cloud and follows the evolution of the clouds over two Jovian days. (One day on Jupiter is approximately 10 hours, which is how long it takes Jupiter to make one complete rotation about its axis.)

    The New Horizons spacecraft was still closing in on the giant planet when it made these observations: Jupiter was 3.4 million kilometers (2.1 million miles) from the New Horizons spacecraft for the LEISA image taken at 19:35 Universal Time on February 26, 2007, and the distance decreased to 2.5 million kilometers (1.6 million miles) for the last image shown. LEISA's spatial resolution scale varied from approximately 210 kilometers (130 miles) for the first image to 160 kilometers (100 miles) for the last one.

    New Horizons scientists originally targeted the region slightly northwest (up and to the left) of the Great Red Spot to search for these special ammonia clouds because that's where they were most easily seen during infrared spectral observations made by the Galileo spacecraft. But unlike the churning, turbulent cloud structures seen near the Great Red Spot during the Galileo era, this region has been quieting down during the past several months and was unusually tranquil when New Horizons passed by. Nevertheless, LEISA managed to find other regions of fresh, upwelling ammonia clouds, and the temporal evolution of one such region is displayed in this figure. In the first image, a fresh ammonia cloud (the blue region) sprouts from between white clouds and a dark elongated region. This blue cloud subsequently stretches along the white-dark border in the next two images.

    These fresh ammonia clouds trace the strong

  10. Two Moons Meet over Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This beautiful image of the crescents of volcanic Io and more sedate Europa was snapped by New Horizons' color Multispectral Visual Imaging Camera (MVIC) at 10:34 UT on March 2, 2007, about two days after New Horizons made its closest approach to Jupiter.

    The picture was one of a handful of the Jupiter system that New Horizons took primarily for their artistic, rather than scientific value. This particular scene was suggested by space enthusiast Richard Hendricks of Austin, Texas, in response to an Internet request by New Horizons scientists for evocative, artistic imaging opportunities at Jupiter.

    This image was taken from a range of 4.6 million kilometers (2.8 million miles) from Io and 3.8 million kilometers (2.4 million miles) from Europa. Although the moons appear close in this view, a gulf of 790,000 kilometers (490,000 miles) separates them. The night side of Io is illuminated here by light reflected from Jupiter, which is out of the frame to the right. Europa's night side is completely dark, in contrast to Io, because that side of Europa faces away from Jupiter.

    Here, Io steals the show with its beautiful display of volcanic activity. Three volcanic plumes are visible. Most conspicuous is the enormous 300-kilometer (190-mile) -high plume from the Tvashtar volcano at the 11 o'clock position on Io's disk. Two much smaller plumes are barely visible: one from the volcano Prometheus, at the 9 o'clock position on the edge of Io's disk, and one from the volcano Amirani, seen between Prometheus and Tvashtar along Io's terminator (the line dividing day and night). The plumes appear blue because of the scattering of light by tiny dust particles ejected by the volcanoes, similar to the blue appearance of smoke. In addition, the contrasting red glow of hot lava can be seen at the source of the Tvashtar plume.

    The images are centered at 1 degree north, 60 degrees west on Io, and 0 degrees north, 149 degrees west on Europa. The color in this

  11. Interplanetary mission design handbook. Volume 1, part 3: Earth to Jupiter ballistic mission opportunities, 1985-2005

    NASA Technical Reports Server (NTRS)

    Sergeyevsky, A. B.; Snyder, G. C.

    1982-01-01

    Graphical data necessary for the preliminary design of ballistic missions to Jupiter are provided. Contours of launch energy requirements, as well as many other launch and Jupiter arrival parameters, are presented in launch date/arrival date space for all launch opportunities from 1985 through 2005. In addition, an extensive text is included which explains mission design methods, from launch window development to Jupiter probe and orbiter arrival design, utilizing the graphical data in this volume as well as numerous equations relating various parameters.

  12. Galileo In-Situ Dust Measurements in Jupiter's Gossamer Rings

    NASA Astrophysics Data System (ADS)

    Krueger, H.; Hamilton, D. P.; Gruen, E.

    Thebe's and Amalthea's orbit. This structure as well as the Thebe ring extension may be explained by variable photoelectric grain charging on the day- and night-sides of Jupiter and the resulting variable susceptibility of the grains to electromagnetic forces. The Galileo measurements in Jupiter's gossamer ring pave the way towards the in-situ investigation of Saturn's E ring with Cassini beginning in July 2004.

  13. Sunward flow in Jupiter's magnetosheath

    NASA Astrophysics Data System (ADS)

    Siscoe, G. L.; Crooker, N. U.; Belcher, J. W.

    1980-01-01

    The position of Voyager crossings of Jupiter's bow shock show a dependence on solar wind pressure to the -1/3 power. This dependence is used to calculate typical bow shock speeds of 50 km/s from Voyager solar wind plasma data. Since the bow shock and magnetopause move approximately in unison in response to solar wind pressure changes, the resulting movement of the magnetosheath at a sizeable fraction of the solar wind speed leads to reversed, sunward flow in large portions of the dayside region when the boundaries are expanding. Voyager 1 plasma data show evidence of such reversed flow.

  14. Comet on target for Jupiter

    NASA Astrophysics Data System (ADS)

    Chapman, C. R.

    1993-06-01

    Comet Shoemaker-Levy 9 is anticipated to collide with the far side of Jupiter in late July, 1994. Although there will be no direct earth observations of the event, associated phenomena will be telescopically observable. Observational results are expected to shed light on how planet rings are formed, how satellites are cratered, the character of million-megaton atmospheric explosions, and the nature of comets. The impact is expected to rival or even exceed the explosive energy of the earth impact hypothesized to have been responsible for the K/T boundary extinctions.

  15. Jupiter's Temperatures--Broad Latitude

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is one of the highest resolution images ever recorded of Jupiter's temperature field. It was obtained by NASA's Galileo mission, with its Photopolarimeter-Radiometer (PPR) experiment, during the seventh of its 10 orbits around Jupiter to date. This map, shown in the left panel, indicates the forces powering Jovian winds, and differentiates between areas of strongest upwelling and downwelling winds in the upper part of the atmosphere. A Hubble Space Telescope Planetary Camera color composite of this same region, taken within 10 hours of the PPR map, is shown in the right panel for the same region, as a reference to the visual clouds. An outline of the region mapped by the PPR is also shown.

    This atmospheric observation covered a broad latitude region, and it shows that the visually dark regions generally have warmer temperatures than the visually light ones, indicating that they are regions of downwelling, dry air which clear out cloud condensate particles. The 'little red spot' at the northernmost part of this image is colder than its surroundings, consistent with it being a region of upwelling and cooling gas. The smaller spots to its southeast (lower right) and other lighter spots in the HST image are all colder than their surroundings, consistent with regions of upwelling and cooling gas. The northern half of the brightest band in the map is brighter than the southern half, and it reveals some detailed structure, down to the 1900- kilometer (1200-mile) resolution of the PPR, which is not always readily correlated with variations of the visual cloud field.

    One surprise of this temperature map involved temperatures near the dark blue-gray feature in the map, an area like the one into which the Probe descended. While large regions of downwelling wind heat the local area elsewhere in Jupiter, this region of vigorous downwelling appears close to being thermally neutral. The drying, downwelling winds may be deeper in the atmosphere than sensed by the PPR

  16. Encounter with Jupiter. [Pioneer 10 space probe

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Pioneer 10 space probe's encounter with the Jupiter is discussed in detail. Tables are presented which include data on the distances during the encounter, times of crossing satellite orbits, important events in the flight near Jupiter, and time of experiments. Educational study projects are also included.

  17. Modelling Jupiter's magnetodisc: implications for the Juno mission

    NASA Astrophysics Data System (ADS)

    Nichols, J. D.; Cowley, S. W. H.; Achilleos, N. A.

    2015-12-01

    Jupiter's magnetosphere is radially stretched in the middle magnetosphere owing to force balance between outward centrifugal, plasma pressure gradient and anisotropy forces, and an inward JxB force associated with an azimuthal current. In this paper we discuss recent modelling of Jupiter's magnetodisc, and discuss the implications for the upcoming Juno mission. In particular, we discuss recent work including anisotropic hot plasma pressure in the computation of the magnetodisc structure. We show that the anisotropy current is comparable to the hot plasma pressure current in the middle magnetosphere between 20-40RJ, and that for reasonable magnetosphere-ionosphere coupling current system parameters, Jupiter's magnetosphere resides close to the limit of the firehose instability. We further show that, using anisotropic pressure, variations in the hot plasma temperature over the range observed by spacecraft data are sufficient to explain the latitudinal changes in the main oval and Ganymede footprint latitudes observed using the Hubble Space Telescope. Juno will traverse the middle magnetosphere in the early-to-mid interval of the main mission, and will provide direct in-situ measurements of the plasma pressures and flows, along with the magnetic field. Using the magnetodisc model, we provide predictions for Juno observations and discuss how these measurements will further constrain the models.

  18. Hot Jupiters from secular planet-planet interactions.

    PubMed

    Naoz, Smadar; Farr, Will M; Lithwick, Yoram; Rasio, Frederic A; Teyssandier, Jean

    2011-05-12

    About 25 per cent of 'hot Jupiters' (extrasolar Jovian-mass planets with close-in orbits) are actually orbiting counter to the spin direction of the star. Perturbations from a distant binary star companion can produce high inclinations, but cannot explain orbits that are retrograde with respect to the total angular momentum of the system. Such orbits in a stellar context can be produced through secular (that is, long term) perturbations in hierarchical triple-star systems. Here we report a similar analysis of planetary bodies, including both octupole-order effects and tidal friction, and find that we can produce hot Jupiters in orbits that are retrograde with respect to the total angular momentum. With distant stellar mass perturbers, such an outcome is not possible. With planetary perturbers, the inner orbit's angular momentum component parallel to the total angular momentum need not be constant. In fact, as we show here, it can even change sign, leading to a retrograde orbit. A brief excursion to very high eccentricity during the chaotic evolution of the inner orbit allows planet-star tidal interactions to rapidly circularize that orbit, decoupling the planets and forming a retrograde hot Jupiter. PMID:21562558

  19. Tour of Jupiter Galilean moons: Winning solution of GTOC6

    NASA Astrophysics Data System (ADS)

    Colasurdo, Guido; Zavoli, Alessandro; Longo, Alessandro; Casalino, Lorenzo; Simeoni, Francesco

    2014-09-01

    The paper presents the trajectory designed by the Italian joint team Politecnico di Torino & Sapienza Università di Roma (Team5), winner of the 6th edition of the Global Trajectory Optimization Competition (GTOC6). In the short time available in these competitions, Team5 resorted to basic knowledge, simple tools and a powerful indirect optimization procedure. The mission concerns a 4-year tour of the Jupiter Galilean moons. The paper explains the strategy that was preliminarily devised and eventually implemented by looking for a viable trajectory. The first phase is a capture that moves the spacecraft from the arrival hyperbola to a low-energy orbit around Jupiter. Six series of flybys follow; in each one the spacecraft orbits Jupiter in resonance with a single moon; criteria to construct efficient chains of resonant flybys are presented. Transfer legs move the spacecraft from resonance with a moon to another one; precise phasing of the relevant moons is required; mission opportunities in a 11-year launch window are found by assuming ballistic trajectories and coplanar circular orbits for the Jovian satellites. The actual trajectory is found by using an indirect technique.

  20. Jupiter's decisive role in the inner Solar System's early evolution.

    PubMed

    Batygin, Konstantin; Laughlin, Greg

    2015-04-01

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ≳ 10-100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution. PMID:25831540

  1. Jupiter's decisive role in the inner Solar System's early evolution.

    PubMed

    Batygin, Konstantin; Laughlin, Greg

    2015-04-01

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ≳ 10-100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.

  2. Hot Jupiters from secular planet-planet interactions.

    PubMed

    Naoz, Smadar; Farr, Will M; Lithwick, Yoram; Rasio, Frederic A; Teyssandier, Jean

    2011-05-12

    About 25 per cent of 'hot Jupiters' (extrasolar Jovian-mass planets with close-in orbits) are actually orbiting counter to the spin direction of the star. Perturbations from a distant binary star companion can produce high inclinations, but cannot explain orbits that are retrograde with respect to the total angular momentum of the system. Such orbits in a stellar context can be produced through secular (that is, long term) perturbations in hierarchical triple-star systems. Here we report a similar analysis of planetary bodies, including both octupole-order effects and tidal friction, and find that we can produce hot Jupiters in orbits that are retrograde with respect to the total angular momentum. With distant stellar mass perturbers, such an outcome is not possible. With planetary perturbers, the inner orbit's angular momentum component parallel to the total angular momentum need not be constant. In fact, as we show here, it can even change sign, leading to a retrograde orbit. A brief excursion to very high eccentricity during the chaotic evolution of the inner orbit allows planet-star tidal interactions to rapidly circularize that orbit, decoupling the planets and forming a retrograde hot Jupiter.

  3. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. III. A PAUCITY OF PROTO-HOT JUPITERS ON SUPER-ECCENTRIC ORBITS

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2015-01-10

    Gas giant planets orbiting within 0.1 AU of their host stars are unlikely to have formed in situ and are evidence for planetary migration. It is debated whether the typical hot Jupiter smoothly migrated inward from its formation location through the proto-planetary disk, or was perturbed by another body onto a highly eccentric orbit, which tidal dissipation subsequently shrank and circularized during close stellar passages. Socrates and collaborators predicted that the latter model should produce a population of super-eccentric proto-hot Jupiters readily observable by Kepler. We find a paucity of such planets in the Kepler sample, which is inconsistent with the theoretical prediction with 96.9% confidence. Observational effects are unlikely to explain this discrepancy. We find that the fraction of hot Jupiters with an orbital period P > 3 days produced by the star-planet Kozai mechanism does not exceed (at two-sigma) 44%. Our results may indicate that disk migration is the dominant channel for producing hot Jupiters with P > 3 days. Alternatively, the typical hot Jupiter may have been perturbed to a high eccentricity by interactions with a planetary rather than stellar companion, and began tidal circularization much interior to 1 AU after multiple scatterings. A final alternative is that early in the tidal circularization process at high eccentricities tidal circularization occurs much more rapidly than later in the process at low eccentricities, although this is contrary to current tidal theories.

  4. The Photoeccentric Effect and Proto-hot Jupiters. III. A Paucity of Proto-hot Jupiters on Super-eccentric Orbits

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2015-01-01

    Gas giant planets orbiting within 0.1 AU of their host stars are unlikely to have formed in situ and are evidence for planetary migration. It is debated whether the typical hot Jupiter smoothly migrated inward from its formation location through the proto-planetary disk, or was perturbed by another body onto a highly eccentric orbit, which tidal dissipation subsequently shrank and circularized during close stellar passages. Socrates and collaborators predicted that the latter model should produce a population of super-eccentric proto-hot Jupiters readily observable by Kepler. We find a paucity of such planets in the Kepler sample, which is inconsistent with the theoretical prediction with 96.9% confidence. Observational effects are unlikely to explain this discrepancy. We find that the fraction of hot Jupiters with an orbital period P > 3 days produced by the star-planet Kozai mechanism does not exceed (at two-sigma) 44%. Our results may indicate that disk migration is the dominant channel for producing hot Jupiters with P > 3 days. Alternatively, the typical hot Jupiter may have been perturbed to a high eccentricity by interactions with a planetary rather than stellar companion, and began tidal circularization much interior to 1 AU after multiple scatterings. A final alternative is that early in the tidal circularization process at high eccentricities tidal circularization occurs much more rapidly than later in the process at low eccentricities, although this is contrary to current tidal theories.

  5. Voyager 1 Jupiter Southern Hemisphere Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie shows a portion of Jupiter in the southern hemisphere over 17Jupiter days. Above the white belt, notice the series of atmospheric vortices headed west. Even these early approach frames show wild dynamics in the roiling environment south of the white belt. Notice the small tumbling white cloud near the center.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 17 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Blue filter around Feb. 1, 1979. The spacecraft was about 37 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  6. Hot-Jupiter Breakfasts Realign Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-08-01

    Two researchers at the University of Chicago have recently developed a new theory to explain an apparent dichotomy in the orbits of planets around cool vs. hot stars. Their model proposes that the spins of cool stars are affected when they ingest hot Jupiters (HJs) early in their stellar lifetimes. A Puzzling Dichotomy: In exoplanet studies, there is a puzzling difference observed between planet orbits around cool and hot (those with Teff ≥ 6250 K) stars: the orbital planes of planets around cool stars are primarily aligned with the host star's spin, whereas the orbital planes of planets around hot stars seem to be randomly distributed. Previous attempts to explain this dichotomy have focused on tidal interactions between the host star and the planets observed in the system. Now Titos Matsakos and Arieh Königl have taken these models a step further — by including in their calculations not only the effects of observed planets, but also those of HJs that may have been swallowed by the star long before we observed the systems. Modeling Meals: Plots of the distribution of the obliquity λ for hot Jupiters around cool hosts (upper plot) and hot hosts (lower plot). The dashed line shows the initial distribution, the bins show the model prediction for the final distribution after the systems evolve, and the black dots show the current observational data. [Matsakos & Königl, 2015]" class="size-thumbnail wp-image-223" height="386" src="http://aasnova.org/wp-content/uploads/2015/08/fig22-260x386.png" width="260" /> Plots of the distribution of the obliquity λ for hot Jupiters around cool hosts (upper plot) and hot hosts (lower plot). The dashed line shows the initial distribution, the bins show the model prediction for the final distribution after the systems evolve, and the black dots show the current observational data. [Matsakos & Königl, 2015] The authors' model assumes that as HJs are formed and migrate inward through the protoplanetary disk, they stall out near

  7. Atmospheric Circulation of Hot Jupiters: Dayside–Nightside Temperature Differences

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Showman, Adam P.

    2016-04-01

    The full-phase infrared light curves of low-eccentricity hot Jupiters show a trend of increasing dayside-to-nightside brightness temperature difference with increasing equilibrium temperature. Here, we present a three-dimensional model that explains this relationship, in order to provide insight into the processes that control heat redistribution in tidally locked planetary atmospheres. This three-dimensional model combines predictive analytic theory for the atmospheric circulation and dayside–nightside temperature differences over a range of equilibrium temperatures, atmospheric compositions, and potential frictional drag strengths with numerical solutions of the circulation that verify this analytic theory. The theory shows that the longitudinal propagation of waves mediates dayside–nightside temperature differences in hot Jupiter atmospheres, analogous to the wave adjustment mechanism that regulates the thermal structure in Earth’s tropics. These waves can be damped in hot Jupiter atmospheres by either radiative cooling or potential frictional drag. This frictional drag would likely be caused by Lorentz forces in a partially ionized atmosphere threaded by a background magnetic field, and would increase in strength with increasing temperature. Additionally, the amplitude of radiative heating and cooling increases with increasing temperature, and hence both radiative heating/cooling and frictional drag damp waves more efficiently with increasing equilibrium temperature. Radiative heating and cooling play the largest role in controlling dayside–nightside temperature differences in both our analytic theory and numerical simulations, with frictional drag only being important if it is stronger than the Coriolis force. As a result, dayside–nightside temperature differences in hot Jupiter atmospheres increase with increasing stellar irradiation and decrease with increasing pressure.

  8. Engineering a Solution to Jupiter Exploration

    NASA Technical Reports Server (NTRS)

    Clark, Karla; Magner, Thomas; Lisano, Michael; Pappalardo, Robert

    2010-01-01

    The Europa Jupiter System Mission (EJSM) would be an international mission with the overall theme of investigating the emergence of habitable worlds around gas giants. Its goals are to (1) explore Europa to investigate its habitability, (2) characterize Ganymede as a planetary object including its potential habitability and (3) explore the Jupiter system as an archetype for gas giants. NASA and ESA have concluded a detailed joint study of a mission to Europa, Ganymede, and the Jupiter system with conceptual orbiters developed by NASA and ESA. The baseline EJSM architecture consists of two primary elements operating simultaneously in the Jovian system: the NASA-led Jupiter Europa Orbiter (JEO), and the ESA-led Jupiter Ganymede Orbiter (JGO). JEO and JGO would execute an intricately choreographed exploration of the Jupiter System before settling into orbit around Europa and Ganymede, respectively. EJSM would directly address themes concerning the origin and evolution of satellite systems and water-rich environments in icy satellites. The potential habitability of the ocean-bearing moons Europa and Ganymede would be investigated, by characterizing the geophysical, compositional, geological, and external processes that affect these icy worlds. EJSM would also investigate Io and Callisto, Jupiter's atmosphere, and the Jovian magnetosphere. By understanding the Jupiter system and unraveling its history, the formation and evolution of gas giant planets and their satellites would be better known. Most importantly, EJSM would shed new light on the potential for the emergence of life in the celestial neighborhood and beyond. The EJSM baseline architecture would provide opportunities for coordinated synergistic observations by JEO and JGO of the Jupiter and Ganymede magnetospheres, the volcanoes and torus of Io, the atmosphere of Jupiter, and comparative planetology of icy satellites. Each spacecraft would conduct both synergistic dual-spacecraft investigations and stand

  9. Jupiter's deep magnetotail boundary layer

    NASA Astrophysics Data System (ADS)

    Nicolaou, G.; McComas, D. J.; Bagenal, F.; Elliott, H. A.; Ebert, R. W.

    2015-06-01

    In 2007 the New Horizons (NH) spacecraft flew by Jupiter for a gravity assist en route to Pluto. After closest approach on day of year (DOY) 58, 2007, NH followed a tailward trajectory that provided a unique opportunity to explore the deep jovian magnetotail and the surrounding magnetosheath. After DOY 132, 16 magnetopause crossings were observed between 1654 and 2429 Jupiter radii (Rj) along the dusk flank tailward of the planet. In some cases the crossings were identified as rapid transitions from the magnetotail to the magnetosheath and vice versa. In other cases a boundary layer was observed just inside the magnetopause. Solar Wind Around Pluto (SWAP) is an instrument on board NH that obtained spectra of low energy ions during the flyby period. We use a forward model including the SWAP instrument response to derive plasma parameters (density, temperature and velocity) which best reproduce the observations. We also vary the plasma parameters in our model in order to fit the observations more accurately on occasions where the measurements exhibit significant variability. We compare the properties of the plasma in the boundary layer with those of the magnetosheath plasma derived in our earlier work. We attempt to estimate the magnetic field in the boundary layer assuming pressure balance between it and the magnetosheath. Finally, we investigate several possible scenarios to assess if magnetopause movement and structure could cause the variations seen in the data.

  10. Longitudinal Variations in Jupiter's Winds

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  11. A study of the time variability of Jupiter's atmospheric structure

    NASA Astrophysics Data System (ADS)

    Kuehn, D. M.; Beebe, R. F.

    1993-02-01

    Aspects of the time-variable nature of the Jovian atmosphere are addressed using high-resolution photometrically calibrated multicolored imaging data obtained over two Jovian apparitions. During the period of observations, Jupiter's South Equatorial Belts (SEB) underwent a drastic brightening and its Equatorial Zone gradually darkened throughout the period. Based on the data, vertically inhomogeneous atmospheric structure models are constructed and used to make direct quantitative comparisons between different latitudinal regions and different epochs. The drastic brightening of the SEB is explained by an increase in both the optical thickness and the single-scattering albedo of the upper tropospheric cloud.

  12. Dynamics of dust in Jupiter's gossamer rings

    NASA Astrophysics Data System (ADS)

    Hamilton, D.; Burns, J.; Krueger, H.; Showalter, M.

    2003-04-01

    Over the past several years, the Galileo spacecraft has drastically improved our knowledge of Jupiter's faint rings. We now know the system to be composed of a main ring 7000km wide whose inner edge blossoms into a vertically-extended halo, and a pair of gossamer rings, each one extending inward from a small moon. These moonlets, Thebe and Amalthea, have large orbital tilts and resulting vertical excursions of 1150km and 4300km, respectively. The vertical thicknesses of the two Gossamer rings accurately match these values, providing compelling evidence that the two small satellites act as the dominant sources of ring material. Ring Material is born during high speed impacts onto the moonlet surfaces, after which the material evolves inward under the action of a dissipative force, either Poynting-Robertson Drag or Resonant Charge Variations. The basic framework for the origin and evolution of the Gossamer Rings is well understood, but there are a few loose ends that are not so easily explained: i) an outward extension of the Thebe Ring, ii) the nature of the dissipative force. In this talk I will report my latest dynamical modeling of the Gossamer rings associated with Thebe and Amalthea, and will discuss how in-situ impact data collected by the Galileo dust detector during the first ever ring "fly-through" may help to resolve some of these and other outstanding issues.

  13. X-Ray Emissions from Jupiter

    NASA Technical Reports Server (NTRS)

    Gladstone, G. R.; Waite, J. H., Jr.; Grodent, D.; Crary, F. J.; Elsner, R. F.; Weisskopf, M. C.; Lewis, W. S.; Jahn, J.-M.; Bhardwaj, A.; Clarke, J. T.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    X-ray emissions from Jupiter have been observed for over 20 years. Jovian x-ray emissions are associated with high-latitude aurora and with solar fluorescence and/or an energetic particle source at low-latitudes as identified by past Einstein and ROSAT observations. Enhanced auroral x-rays were also observed to be associated with the impact of Comet Shoemaker-Levy 9. The high-latitude x-ray emissions are best explained by energetic sulfur and oxygen ion precipitation from the Jovian magnetosphere, a suggestion that has been confirmed by recent Chandra ACIS observations. Exciting new information about Jovian x-ray emissions has been made possible with Chandra's High Resolution Camera. We report here for the first time the detection of a forty minute oscillation associated with the Jovian x-ray aurora. With the help of ultraviolet auroral observations from Hubble Space Telescope, we pinpoint the auroral mapping of the x-rays and provide new information on the x-ray source mechanism.

  14. Analysis of chorus emissions at Jupiter

    NASA Astrophysics Data System (ADS)

    Coroniti, F. V.; Scarf, F. L.; Kennel, C. F.; Kurth, W. S.

    1984-06-01

    The emissions in the chorus frequency band which were detected on the Voyager 1 inbound pass between about ten and six Jupiter radii are surveyed. An overview of the plasma and wave observations during the inbound pass is presented and the spatial regions in which chorus band signals were observed are discussed. A series of wide-band frequency-time frames which characterize the onset of two observed intervals of chorus band activity is displayed. A detailed examination is made of the spectra for rising chorus which sweeps upward in frequency from 0.2 to 0.5 times the electron cyclotron frequency f(c). Two temporally successive wide-band frames in which several types of chorus band emissions were observed are discussed. The spatial morphology of chorus is discussed in terms of the electron energies which resonate with whistler mode waves. A recent theory of chorus generation is reviewed along with theories and a model explaining the narrow-band emissions above f(c)/2.

  15. Visible spectral slope survey of Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Erasmus, Nicolas; Rivkin, Andrew S.; Sickafoose, Amanda A.

    2016-10-01

    Jupiter's Trojans are predicted by the Nice Model [1,2] to be Trans-Neptunian Objects (TNOs) that moved from 30+ AU to 5.2 AU during the early evolution period of the Solar System. This model, predicting giant planet migration and widespread transport of material throughout the Solar System, is however still lacking important constraints. Correlations between the composition, size, and orbital geometry of Jupiter's Trojans can provide additional information to test predicted migration and evolution models.Two main colour groups have been observed, roughly equivalent to the C (plus low-albedo X) and D classes with distinguishable spectral slopes, and one interpretation is that the two groups have different compositions [3]. Independent compositions together with hints of differing orbital inclination distributions could imply separate formation locations; therefore, determining the relative fractions of C and D asteroids at different sizes would provide a key test for Solar System dynamical models. However, there is a caveat: the distinct colour groups could also arise by other means. Regolith processes or "space weathering" such as micrometeorite impacts and UV irradiation of ice are also plausible explanations for a range of spectrographic slopes from C-like to D-like [4].Here we report on our latest survey observations at Sutherland, South Africa of approximately 50 Trojan targets using the Sutherland High Speed Optical Camera (SHOC) [5] on the 74" telescope. These observations are part of a larger multi-telescope survey to determine the spectral slopes (C-like or D-like) for multiple Trojans, focusing on those of small size. These slopes can be used to determine the relative fraction of C+X and D asteroids at different sizes to determine whether what is seen is more consistent with regolith processes or different compositions.References:[1] A. Morbidelli, et al. Nature, 435, 462-465, (2005)[2] R. Gomes, et al. Nature 435, 466-469 (2005)[3] J.P. Emery, et al. The

  16. Atmospheric Heat Redistribution on Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Perez-Becker, Daniel; Showman, Adam P.

    2013-10-01

    Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—and thus have a larger day-night temperature contrast—than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a shallow-water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, τwave, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when \\tau _{wave}\\sim \\sqrt{\\tau _{rad}/\\Omega }, where τrad is the radiative relaxation time and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed as τrad ~ τvert, where τvert is the timescale for a fluid parcel to move vertically over the difference in day-night thickness. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τrad and the horizontal day-night advection timescale,

  17. Atmospheric Heat Redistribution on Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Perez-Becker, D.; Showman, A. P.

    2013-12-01

    Infrared lightcurves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides---and thus have a larger day-night temperature contrast---than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. We present a two-layer shallow water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory that shows that the timescale for gravity waves to propagate horizontally over planetary scales, τwave, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τwave ~ (τrad/Ω)1/2, where τrad is the radiative relaxation time, and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed in terms of τvert, the timescale for a fluid parcel to move vertically over the difference in day-night thickness. The transition then occurs when τrad ~ τvert. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τrad and the timescale for large-scale horizontal

  18. Atmospheric Heat Redistribution on Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Perez-Becker, Daniel; Showman, A. P.

    2013-10-01

    Infrared lightcurves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides---and thus have a larger day-night temperature contrast---than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. We present a two-layer shallow water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory that shows that the timescale for gravity waves to propagate horizontally over planetary scales, τwave, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τwave ~ (τrad/Ω)1/2, where τrad is the radiative relaxation time, and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed in terms of τvert, the timescale for a fluid parcel to move vertically over the difference in day-night thickness. The transition then occurs when τrad ~ τvert. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τrad and the timescale for large-scale horizontal

  19. ATMOSPHERIC HEAT REDISTRIBUTION ON HOT JUPITERS

    SciTech Connect

    Perez-Becker, Daniel; Showman, Adam P.

    2013-10-20

    Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—and thus have a larger day-night temperature contrast—than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a shallow-water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, τ{sub wave}, plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τ{sub wave}∼√(τ{sub rad}/Ω), where τ{sub rad} is the radiative relaxation time and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed as τ{sub rad} ∼ τ{sub vert}, where τ{sub vert} is the timescale for a fluid parcel to move vertically over the difference in day-night thickness. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τ{sub rad} and the horizontal day

  20. Juno and Jupiter's Magnetic Field (Invited)

    NASA Astrophysics Data System (ADS)

    Bloxham, J.; Connerney, J. E.; Jorgensen, J. L.

    2013-12-01

    The Juno spacecraft, launched in August 2011, will reach Jupiter in early July 2016, where it will enter a polar orbit, with an 11 day period and a perijove altitude of approximately 5000 km. The baseline mission will last for one year during which Juno will complete 32 orbits, evenly spaced in longitude. The baseline mission presents an unparalleled opportunity for investigating Jupiter's magnetic field. In many ways Jupiter is a better planet for studying dynamo-generated magnetic fields than the Earth: there are no crustal fields, of course, which otherwise mask the dynamo-generated field at high degree; and an orbiting spacecraft can get proportionately much closer to the dynamo region. Assuming Jupiter's dynamo extends to 0.8 Rj, Juno at closet approach is only 0.3 Rc above the dynamo, while Earth orbiting magnetic field missions sample the field at least 1 Rc above the dynamo (where Rc is the respective outer core or dynamo region radius). Juno's MAG Investigation delivers magnetic measurements with exceptional vector accuracy (100 ppm) via two FGM sensors, each co-located with a dedicated pair of non-magnetic star cameras for attitude determination at the sensor. We expect to image Jupiter's dynamo with unsurpassed resolution. Accordingly, we anticipate that the Juno magnetic field investigation may place important constraints on Jupiter's interior structure, and hence on the formation and evolution of Jupiter.

  1. HUBBLE CLICKS IMAGES OF IO SWEEPING ACROSS JUPITER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.' These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2. The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes. 'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz. A Trip Around Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut. These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye. The bright patches on Io

  2. Hubble Clicks Images of Io Sweeping Across Jupiter

    NASA Technical Reports Server (NTRS)

    1999-01-01

    While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.'

    These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2.

    The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes.

    'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz.

    A Trip Around Jupiter

    The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days.

    The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut.

    These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye

  3. Document delivery by the Jupiter Library Consortium

    NASA Technical Reports Server (NTRS)

    Wessels, Robert H. A.

    1994-01-01

    The Jupiter library consortium consists of 4 of the leading libraries in the Netherlands. During 1993 Jupiter received 600,000 requests for copies of journal articles, or 70 percent of all external article requests in the Netherlands. Over 90 percent of the requested documents were delivered from a collection of 40,000 current international journal subscriptions. Jupiter and its affiliate libraries are non-profit organizations belonging to, and serving, the scientific and technical research community. The usage of the current journal collection of the libraries was analyzed to improve the cost/benefit ratio.

  4. Assessment of Jupiter's trapped radiation by pioneer

    NASA Technical Reports Server (NTRS)

    Mihalov, J. D.

    1972-01-01

    The experiments planned for Pioneers F and G during their Jupiter flybys are discussed. The complement includes four energetic charged particle experiments: University of Iowa package consisting of Geiger-Mueller tubes; University of California, San Diego, trapped radiation package consisting of solid state detectors, thin scintillators, and an alcohol water Cerenkov radiator; University of Chicago package containing charged particle detectors; and a Goddard Space Flight Center package containing solid state, cosmic ray detectors. Other experiments are the Jet Propulsion Laboratory magnetometer and the Ames Research Center plasma analyzer. Pitch angle distributions at Jupiter, and the capabilities for unambiguous identification of energetic protons at Jupiter are also discussed.

  5. Possible infrared aurorae on Jupiter

    NASA Technical Reports Server (NTRS)

    Caldwell, J.; Gillett, F. C.; Tokunaga, A. T.

    1980-01-01

    Infrared brightenings near the poles of Jupiter at 8 microns were observed in early 1980 by the NASA 3-m Infrared Telescope Facility at Mauna Kea and the Mayall 4-m telescope at the Kitt Peak National Observatory. It is suggested that these brightenings are related to the auroral zones which are determined by the magnetic mapping of the magnetotail onto the atmosphere, rather than by the Io flux tube. They were present in both hemispheres in January, present only in the north in February, and probably absent in the south in March. When visible, they were only seen in the hemisphere where the auroral zone was oriented toward the earth and absent otherwise.

  6. Strong Langmuir turbulence at Jupiter?

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.; Robinson, P. A.

    1992-01-01

    Langmuir wave packets with short scale lengths less than an approximately equal to 100 lambda e have been observed in Jupiter's foreshock. Theoretical constraints on the electric fields and scale sizes of collapsing wave packets are summarized, extended and placed in a form suitable for easy comparison with Voyager and Ulysses data. The published data are reviewed and possible instrumental underestimation of fields discussed. New upper limits for the fields of the published wave packets are estimated. Wave packets formed at the nucleation scale from the observed large-scale fields cannot collapse because they are disrupted before collapse occurs. The published wave packets are quantitatively inconsistent with strong turbulence collapse. Strict constraints exist for more intense wave packets to be able to collapse: E greater than or approximately equals to 1-8 mV/m for scales less than or approximately equal to 100 lambda e. Means for testing these conclusions using Voyager and Ulysses data are suggested.

  7. A New Look at Jupiter: Results at the Now Frontier. [Pioneer 10, interplanetary space, and Jupiter atmosphere

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Pioneer 10's encounter with Jupiter is discussed along with the interplanetary space beyond the orbit of Mars. Other topics discussed include the size of Jupiter, the Galilean satellites, the magnetic field of Jupiter, radiation belts, Jupiter's weather and interior, and future exploration possibilities. Educational projects are also included.

  8. Laboratory Investigations of Jupiter's Chromophores

    NASA Astrophysics Data System (ADS)

    Carlson, Robert W.; Baines, K. H.

    2009-09-01

    Ultraviolet- irradiated ammonium hydrosulfide (NH4SH) ice and its byproducts have long been postulated to be the source of the reddish coloring of the Great Red Spot (e,g., Lewis and Prinn (1970), West et al., 1986, Baines et al., 2004). NH4SH aerosols created near the 2.5-bar level on Jupiter may be transported upward to the 300-mbar level in the anti-cylonic environment of the Great Red Spot, where they are then subjected to solar ultraviolet irradiation. The irradiated ices and byproducts could be concentrated by the vortex action of the GRS, enhancing the reddish color above that which would be seen by an irradiated NH4SH cloud in the typical zone/belt structure of Jupiter. We have initiated an experimental study of potential sulfurous chromophores using a photolysis flow cell with temperatures and pressures controlled to simulate Jovian conditions. Photolysis is produced using Hg, Zn, or D2 lamps, each with different spectral characteristics. Analysis of the photoproducts is performed using ultraviolet, visible, and infrared spectroscopy and the gaseous and sublimed products are also characterized using mass spectroscopy. Our first experiments have been with NH4SH condensed from mixtures of NH3 and H2S at 240 K. The irradiated condensate exhibits broad ultraviolet and visible features that may be attributed to absorptions by polysulfide ions (SnS2-) in ammonium polysulfide [(NH4+)2 SnS2-] and possibly to absorptions by hydropolysulfide ions (HSnS-). The measurements and comparisons to Jovian spectra will be presented.

  9. A transition in the cloud composition of hot Jupiters atmospheres

    NASA Astrophysics Data System (ADS)

    Parmentier, Vivien; Jonathan, Fortney; Showman, Adam P.; Marley, Mark; Morley, Caroline

    2015-12-01

    Over a large range of equilibrium temperatures clouds seem to dominate the transmission spectrum of Hot Jupiters atmospheres and no trend allowing the classification of these objects have yet emerged. Recently observations of the light reflected by Hot Jupiters atmospheres shed a new light on the cloud distribution on the dayside of these planets : for a handful of planets clouds are more abundant on the western than on the eastern side of the dayside hemisphere and, more importantly, this asymmetry depends on the equilibrium temperature of the planet.Here we use a grid of 3D global circulation models to show that a single cloud species is unable to explain the recent Kepler observations. The cloud asymmetry on the dayside is a strong function of the condensation temperature of the cloud species which allow us to determine the composition of the clouds present in these planets. We show that a transition between silicate clouds and sulfide clouds appear at equilibrium temperatures of 1600K. A mechanism such as the presence of a deep cold trap is necessary to explain this transi- tion. Furthermore, we show that the western limb temperature is always cold, independently of the equilibrium temperature of the planet, allowing cloud particles to form even in the most irradiated planets as seen in the observations.Our results provide the first evidence for a transition in the cloud species of hot Jupiters similar to the L/T Brown Dwarf transition. We showed that inhomogeneous dayside and limbs cloud coverage are expected what should affect the retrieved molecular abundances from emission and transmission spectra of these planets.

  10. On the speed of gravity and the jupiter/quasar measurement

    SciTech Connect

    Samuel, Stuart

    2004-08-15

    I present the theory and analysis behind the experiment by Fomalont and Kopeikin involving Jupiter and quasar J0842 + 1845 that purported to measure the speed of gravity. The computation of the v{sub J}/c correction to the gravitational time delay difference relevant to the experiment is derived, where v{sub J} is the speed of Jupiter as measured from Earth. Since the v{sub J}/c corrections are too small to have been measured in the Jupiter/quasar experiment, it is impossible that the speed of gravity was extracted from the data, and I explain what went wrong with the data analysis. Finally, mistakes are shown in papers by Fomalont and Kopeikin intended to rebut my work and the work of others.

  11. Voyager spacecraft images of Jupiter and Saturn.

    PubMed

    Birnbaum, M M

    1982-01-15

    The images of Jupiter and Saturn and their satellites taken by the Voyager spacecraft TV cameras are shown and described. The scientific findings of the Voyager mission instruments and experiments are summarized.

  12. Kepler constraints on planets near hot Jupiters

    SciTech Connect

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2:1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  13. Kepler constraints on planets near hot Jupiters

    PubMed Central

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

    2012-01-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2∶1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  14. Another View of June Fireball at Jupiter

    NASA Video Gallery

    Amateur astronomer Christopher Go, of Cebu, Philippines, captured this video of a fireball burning up in the Jupiter atmosphere on June 3, 2010. Go recorded the video at 55 frames per second in blu...

  15. Kepler constraints on planets near hot Jupiters.

    PubMed

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  16. Chandra Image Reveals Auroral X-rays at Poles of Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This Chandra image of Jupiter shows concentrations of aurora x-rays near the north and south poles due to a single `hot spot' that pulsates with a period of 45 minutes, similar to high-latitude radio pulsation previously detected by NASA's Galileo and Cassini spacecraft. Previous x-ray detections of Jupiter have been made with other x-ray telescopes, but did not reveal that the sources of the x-rays, energetic oxygen and sulfur ions, would be located so near the poles. Previous theories held that ions were mostly coming from Jupiter's moon, lo. Chandra's ability to pinpoint the source of the x-rays discards this theory since ions coming from near lo's orbit carnot reach the observed high latitudes. One possibility is that particles flowing out from the Sun are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from Jupiter's north pole to the south pole in an oscillating motion that could explain the pulsation.

  17. Satellite Footprints Seen in Jupiter Aurora

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This is a spectacular NASA Hubble Space Telescope close-up view of an electric-blue aurora that is eerily glowing one half billion miles away on the giant planet Jupiter. Auroras are curtains of light resulting from high-energy electrons racing along the planet's magnetic field into the upper atmosphere. The electrons excite atmospheric gases, causing them to glow. The image shows the main oval of the aurora, which is centered on the magnetic north pole, plus more diffuse emissions inside the polar cap.

    Though the aurora resembles the same phenomenon that crowns Earth's polar regions, the Hubble image shows unique emissions from the magnetic 'footprints' of three of Jupiter's largest moons. (These points are reached by following Jupiter's magnetic field from each satellite down to the planet).

    Auroral footprints can be seen in this image from Io (along the lefthand limb), Ganymede (near the center), and Europa (just below and to the right of Ganymede's auroral footprint). These emissions, produced by electric currents generated by the satellites, flow along Jupiter's magnetic field, bouncing in and out of the upper atmosphere. They are unlike anything seen on Earth.

    This ultraviolet image of Jupiter was taken with the Hubble Space Telescope Imaging Spectrograph (STIS) on November 26, 1998. In this ultraviolet view, the aurora stands out clearly, but Jupiter's cloud structure is masked by haze.

    December 14, 2000 inaugurates an intensive two weeks of joint observation of Jupiter's aurora by Hubble and the Cassini spacecraft. Cassini will make its closest approach to Jupiter enroute to a July 2004 rendezvous with Saturn. A second campaign in January 2001 will consist of Hubble images of Jupiter's day-side aurora and Cassini images of Jupiter's night-side aurora, obtained just after Cassini has flown past Jupiter. The team will develop computer models that predict how the aurora operates, and this will yield new insights into the effects of the solar wind

  18. Tidal dissipation and obliquity evolution in hot Jupiter systems

    SciTech Connect

    Valsecchi, Francesca; Rasio, Frederic A.

    2014-05-10

    Two formation scenarios have been proposed to explain the tight orbits of hot Jupiters. They could be formed in orbits with a small inclination (with respect to the stellar spin) via disk migration, or in more highly inclined orbits via high-eccentricity migration, where gravitational interactions with a companion and tidal dissipation are at play. Here we target hot Jupiter systems where the misalignment λ has been inferred observationally and we investigate whether their properties are consistent with high-eccentricity migration. Specifically, we study whether stellar tides can be responsible for the observed distribution of λ and orbital separations. Improving on previous studies, we use detailed models for each star, thus accounting for how convection (and tidal dissipation) depends on stellar properties. In line with observations suggesting that hotter stars have higher λ, we find that λ increases as the amount of stellar surface convection decreases. This trend supports the hypothesis that tides are the mechanism shaping the observed distribution of λ. Furthermore, we study the past orbital evolution of five representative systems, chosen to cover a variety of temperatures and misalignments. We consider various initial orbital configurations and integrate the equations describing the coupled evolution of the orbital separation, stellar spin, and misalignment. We account for stellar tides and wind mass loss, stellar evolution, and magnetic braking. We show that the current properties of these five representative systems can be explained naturally, given our current understanding of tidal dissipation and with physically motivated assumptions for the effects driving the orbital evolution.

  19. Significant Science at Jupiter Using Solar Power

    NASA Technical Reports Server (NTRS)

    Reitsema, H. J.; Smith, E. J.; Spilker, T.; Reinert, R.

    2001-01-01

    Missions to the Outer Planets are challenging for a number of reasons, primary of which is the low output of solar arrays at large heliocentric distances. The INSIDE Jupiter mission is a Discovery concept for a science investigation at Jupiter that is capable of producing major studies of the Jovian internal structure and ionospheric-magnetospheric coupling. Additional information is contained in the original extended abstract.

  20. Hubble Provides Complete View of Jupiter's Auroras

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA's Hubble Space Telescope has captured a complete view of Jupiter's northern and southern auroras.

    Images taken in ultraviolet light by the Space Telescope Imaging Spectrograph (STIS) show both auroras, the oval-shaped objects in the inset photos. While the Hubble telescope has obtained images of Jupiter's northern and southern lights since 1990, the new STIS instrument is 10 times more sensitive than earlier cameras. This allows for short exposures, reducing the blurring of the image caused by Jupiter's rotation and providing two to five times higher resolution than earlier cameras. The resolution in these images is sufficient to show the 'curtain' of auroral light extending several hundred miles above Jupiter's limb (edge). Images of Earth's auroral curtains, taken from the space shuttle, have a similar appearance. Jupiter's auroral images are superimposed on a Wide Field and Planetary Camera 2 image of the entire planet. The auroras are brilliant curtains of light in Jupiter's upper atmosphere. Jovian auroral storms, like Earth's, develop when electrically charged particles trapped in the magnetic field surrounding the planet spiral inward at high energies toward the north and south magnetic poles. When these particles hit the upper atmosphere, they excite atoms and molecules there, causing them to glow (the same process acting in street lights).

    The electrons that strike Earth's atmosphere come from the sun, and the auroral lights remain concentrated above the night sky in response to the 'solar wind.'

  1. Jupiter in True and False Color

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These color composite frames of the mid-section of Jupiter were of narrow angle images acquired on December 31, 2000, a day after Cassini's closest approach to the planet. The smallest features in these frames are roughly 60 kilometers. The left is natural color, composited to yield the color that Jupiter would have if seen by the naked eye. The right frame is composed of 3 images: two were taken through narrow band filters centered on regions of the spectrum where the gaseous methane in Jupiter's atmosphere absorbs light, and the third was taken in a red continuum region of the spectrum, where Jupiter has no absorptions. The combination yields an image whose colors denote the height of the clouds. Red regions are deep water clouds, bright blue regions are high haze (like the blue covering the Great Red Spot). Small, intensely bright white spots are energetic lightning storms which have penetrated high into the atmosphere where there is no opportunity for absorption of light: these high cloud systems reflect all light equally. The darkest blue regions -- for example, the long linear regions which border the northern part of the equatorial zone, are the very deep 'hot spots', seen in earlier images, from which Jovian thermal emission is free to escape to space. This is the first time that global images of Jupiter in all the methane and attendant continuum filters have been acquired by a spacecraft. From images like these, the stratigraphy of Jupiter's dynamic atmosphere will be determined.

  2. (abstract) MEASURE-Jupiter: Low Cost Missions to Explore Jupiter in the Post-Galileo Era

    NASA Technical Reports Server (NTRS)

    Wallace, R. A.; Stern, S. A.; Ayon, J. A.; Lane, A. L.; Nunez, C. L.; Sauer, C. G.; Stetson, D. G.; West, R. A.

    1994-01-01

    MEASURE-Jupiter is a new mission concept for the exploration of giant planets, with initial application to Jupiter. By flying sets of lightweight spacecraft with highly focused measurement objectives, it is designed to break the apparent impass in giant planet exploration beyond Cassini. The MEASURE-Jupiter concept is characterized by: 1) intensive exploration of a giant planet system, 2) multiple small missions flown in focused waves using spacecraft costing $100M to $200M, and 3) mission sets launched every 2 to 3 years. Why Jupiter? Jupiter is the most complex planetary system in the Solar System with many scientifically intriguing bodies and phenomena to explore. The Galileo mission will scratch the surface of the exploration of Jupiter, posing many questions for the MEASURE-Jupiter missions to address. Jupiter is also the easiest planet in the Outer Solar System to reach, making possible flight times of 2 years and total mission durations of 3 years or less. Concept design studies have uncovered a number of scientifically rewarding, simple, low-cost mission options. These options have the additional attraction of being able to launch on 2-year trajectories to Jupiter with low-cost Delta II expendable launch vehicles. A partial list of mission concepts studied to date include: Io Very Close Flyby, Jupiter Close Polar Pass, Mini-Orbiters, and Galilean Satellite Penetrators. Key to the realization of the MEASURE-Jupiter missions is the judicious use of the new low power consuming advanced technology and applicable systems from the Pluto Fast Flyby mission spacecraft design. Foremost of the new technologies planned for inclusion are the elements of hybrid solar array/battery power systems which make it possible to perform the identified missions without the need for Radioactive Thermoelectric Generators (RTGs). This relieves the mission design of the attendant programmatic complexities, cost, and constraints attendant with the use of RTGs.

  3. Transits and Occultations of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Haynes, Korey

    Since the first discovery of an extrasolar planet less than two decades ago, astronomers have learned how to measure not only the masses, radii, and orbital elements of a wide range exoplanets (far exceeding the parameters of our own solar system), but also their atmospheric temperatures and chemical compositions. Even with plentiful observations, many questions remain unanswered. Measuring atmospheric abundances based on observed absorption features can answer questions about carbon-to-oxygen (C/O) ratios, but many of the literature results rely on broadband photometry, where multiple absorption features become blended, thus complicating interpretation. Combining measurements across a long spectral baseline using multiple different instruments can be a powerful lever for studying the spectral energy distributions (SEDs) of exoplanets, but there is often a lack of consensus between observing teams and instruments. Some differences may be due to genuine temporal variations in the exoplanet atmospheres, while others are more likely due to differences in instrument characterization and data analysis. Resolved spectra of exoplanets, particularly in the infrared, where strong features due to water, carbon monoxide, carbon dioxide, and methane are expected, could break model degeneracies and answer many questions about C/O ratios and pressure-temperature atmospheric structures. While not the first, Wide Field Camera 3 (WFC3) on the Hubble Space Telescope is the only current space-based opportunity to study spectrally resolved exoplanet atmospheres in the infrared. We focus on hot Jupiter type exoplanets, and use WFC3 (as well as ancillary data from Spitzer and ground based facilities) to try to break degeneracies between models, resolve past observing conflicts, and unambiguously determine these planets' atmospheric composition and structure. We discover unambiguous detections of water in exoplanet atmospheres, and the first spectroscopic evidence for a temperature

  4. JUpiter ICy Moons Explorer (JUICE): The ESA L1 Mission to the Jupiter System

    NASA Astrophysics Data System (ADS)

    Dougherty, M. K.; Grasset, O.; Erd, C.; Titov, D.; Bunce, E.; Coustenis, A.; Blanc, M.; Coates, A.; Drossart, P.; Fletcher, L.; Hussmann, H.; Jaumann, R.; Krupp, N.; Prieto-Ballesteros, O.; Tortora, P.; Tosi, F.; Van Hoolst, T.

    2012-10-01

    The Jupiter Icy Moons Explorer (JUICE) mission has recently been selected by ESA as the first large mission within the Cosmic Visions 2015-2025 plan. We will introduce the mission that is being developed to thoroughly explore the Jupiter system with focus on the largest satellite, Ganymede.

  5. Jupiter and Its Galilean Satellites

    NASA Technical Reports Server (NTRS)

    McGrath, Melissa A.

    2012-01-01

    Jupiter is one of the two most studied planets other than Earth in our Solar System. It is the largest, fastest rotating, has the strongest magnetic field, and an incredibly diverse set of satellites, most prominent of which are the four Galilean satellites discovered in 1610. Io, Europa, Ganymede and Callisto encompass some of the most bizarre environments known in the solar system, from Io, the most volcanically active and perhaps the most inhospitable body known, to Europa, currently thought to be the most likely extraterrestrial abode for habitability, to Ganymede, which is larger than Mercury, and Callisto, which has the oldest surface known in the solar system with the widest array of crater morphologies known. One of the premier areas of scientific return in solar system research in the past 15 years, due in large part to the Galileo mission and observations by the Hubble Space Telescope, has been a remarkable increase in our knowledge about these satellites. Discoveries have been made of tenuous molecular oxygen atmospheres on Europa and Ganymede, a magnetic field and accompanying auroral emissions at the poles of Ganymede, and of ozone and sulfur dioxide embedded in the surfaces of Europa, Ganymede and Callisto. Io's unusual sulfur dioxide atmosphere, including its volcanic plumes and strong electrodynamic interaction with magnetospheric plasma, has finally been quantitatively characterized. This talk will present highlights from the recent discoveries and advances in our understanding of these fascinating objects.

  6. Temporal Variations in Jupiter's Atmosphere

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Chanover, N. J.; Yanamandra-Fisher, P.; Hammel, H. B.; dePater, I.; Noll, K.; Wong, M.; Clarke, J.; Sanchez-Levega, A.; Orton, G. S.; Gonzaga, S.

    2009-01-01

    In recent years, Jupiter has undergone many atmospheric changes from storms turning red to global. cloud upheavals, and most recently, a cornet or asteroid impact. Yet, on top of these seemingly random changes events there are also periodic phenomena, analogous to observed Earth and Saturn atmospheric oscillations. We will present 15 years of Hubble data, from 1994 to 2009, to show how the equatorial tropospheric cloud deck and winds have varied over that time, focusing on the F953N, F41 ON and F255W filters. These filters give leverage on wind speeds plus cloud opacity, cloud height and tropospheric haze thickness, and stratospheric haze, respectively. The wind data consistently show a periodic oscillation near 7-8 S latitude. We will discuss the potential for variations with longitude and cloud height, within the calibration limits of those filters. Finally, we will discuss the role that large atmospheric events, such as the impacts in 1994 and 2009, and the global upheaval of 2007, have on temporal studies, This work was supported by a grant from the NASA Planetary Atmospheres Program. HST observational support was provided by NASA through grants from Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract NAS5-26555.

  7. The possible contamination of Jupiter

    NASA Technical Reports Server (NTRS)

    Garcia, Joe

    1988-01-01

    The Galileo probe, though at present its future is uncertain, would, if not sterilized, represent a good chance of contaminating Jupiter. Most scientists opposed to sterilizing the probe argue that to order the probe sterilized would be the death of the project, since sterilization would entail a reconstruction of the probe, and there are not enough funds to accomplish this. These scientists, however, are ignoring a relatively simple and inexpensive alternative to the traditional heat sterilization method. The main threat of contamination comes from Galileo's exterior surfaces: the shell of the probe and its parachute. The probe innermost components would not represent a threat since the probe is sealed. In light of the fact that only the exterior of Galileo would have to be sterilized, heat would not have to be used as a method of sterilization. Instead, various gas mixtures could be sprayed entirely over the probe and its parachute, gases which would kill any and all bacteria. This idea is more thoroughly examined.

  8. Hot Jupiters and cool stars

    SciTech Connect

    Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

    2014-10-10

    Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M {sub ☉}), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

  9. Structure and statistical properties of plasmoids in Jupiter's magnetotail

    NASA Astrophysics Data System (ADS)

    Vogt, Marissa F.; Jackman, Caitriona M.; Slavin, James A.; Bunce, Emma J.; Cowley, Stanley W. H.; Kivelson, Margaret G.; Khurana, Krishan K.

    2014-02-01

    Plasmoids and other reconnection-related signatures have been observed in Jupiter's magnetotail through analysis of magnetic field and energetic particle data. Previous studies have established the spatial distribution and recurrence period of tail reconnection events, and identified the location of a statistical X-line separating inward and outward flow. Here we present new analysis focusing specifically on 43 plasmoid signatures observed in magnetometer data in order to establish the average properties and internal structure of Jovian plasmoids. We present statistics on the observed plasmoid length scale, duration, radial position, and local time distribution. On average, the observed plasmoids have a ~3 RJ radial extent and ~7 min duration and result in the closure of ~4-8 GWb of open flux from reconnection of open field lines in the postplasmoid plasma sheet. We also determine the amount of mass released and the magnetic flux closed in order to understand the role of tail reconnection in the transport of mass and flux in Jupiter's magnetosphere. The observed plasmoid properties are consistent with a mass loss rate of ~0.7-120 kg/s and a flux closure rate of ~7-70 GWb/d. We conclude that tail reconnection and plasmoid release is an important method of flux transport at Jupiter but likely cannot account for the mass input from Io, suggesting that additional mass loss mechanisms may be significant. Finally, we examine the plasmoid interior structure through minimum variance analysis and find that most plasmoids lack a core field and are better described by magnetic loops rather than flux ropes.

  10. RAPID FORMATION OF SATURN AFTER JUPITER COMPLETION

    SciTech Connect

    Kobayashi, Hiroshi; Ormel, Chris W.; Ida, Shigeru E-mail: ormel@astro.berkeley.edu

    2012-09-01

    We have investigated Saturn's core formation at a radial pressure maximum in a protoplanetary disk, which is created by gap opening by Jupiter. A core formed via planetesimal accretion induces the fragmentation of surrounding planetesimals, which generally inhibits further growth of the core by removal of the resulting fragments due to radial drift caused by gas drag. However, the emergence of the pressure maximum halts the drift of the fragments, while their orbital eccentricities and inclinations are efficiently damped by gas drag. As a result, the core of Saturn rapidly grows via accretion of the fragments near the pressure maximum. We have found that in the minimum-mass solar nebula, kilometer-sized planetesimals can produce a core exceeding 10 Earth masses within two million years. Since Jupiter may not have undergone significant type II inward migration, it is likely that Jupiter's formation was completed when the local disk mass has already decayed to a value comparable to or less than Jovian mass. The expected rapid growth of Saturn's core on a timescale comparable to or shorter than the observationally inferred disk lifetime enables Saturn to acquire the current amount of envelope gas before the disk gas is completely depleted. The high heat energy release rate onto the core surface due to the rapid accretion of the fragments delays onset of runaway gas accretion until the core mass becomes somewhat larger than that of Jupiter, which is consistent with the estimate based on interior modeling. Therefore, the rapid formation of Saturn induced by gap opening of Jupiter can account for the formation of multiple gas giants (Jupiter and Saturn) without significant inward migration and larger core mass of Saturn than that of Jupiter.

  11. Alternative Evolution and Internal Structure for Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Vazan, Allona; Helled, Ravit; Podolak, Morris; Kovetz, Attay

    2016-10-01

    The internal structure of gas giant planets may be more complex than the commonly assumed core-envelope structure with an adiabatic temperature profile. Different primordial internal structures as well as various physical processes can lead to non-homogenous compositional distributions. A non-homogenous internal structure has a significant impact on the thermal evolution and final structure of the planets. Here we present alternative structure and evolution models for Jupiter and Saturn allowing for both adiabatic and non-adiabatic evolution. In convective regions we calculate the mixing of heavy elements by convection, as these planets evolve. We present the thermal and structural evolution of the planets accounting for various initial composition gradients, and in the case of Saturn, include the formation of a helium-rich region as a result of helium rain. We investigate the stability of the structure against convection, and find that the helium shell in Saturn remains stable and does not mix with the rest of the envelope. In other cases, convection mixes the planetary interior despite the existence of compositional gradients, leading to enrichment of the envelope with metals. We show that non-adiabatic structures (and cooling histories) for both Jupiter and Saturn are feasible, and the interior temperatures in that case are much higher that for standard adiabatic models. Moreover, we show that non-adiabatic evolution can suggest more than one mechanism to explain the current structures, including Saturn's high luminosity. We conclude that the internal structure is directly linked to the formation and evolution history of the planet. These alternative internal structures of Jupiter and Saturn should be considered when interpreting the upcoming Juno and Cassini data.

  12. In-Situ Dust Measurements in Jupiter's Gossamer Rings

    NASA Astrophysics Data System (ADS)

    Krueger, H.; Gruen, E.; Hamilton, D. P.

    2003-04-01

    Jupiter's ring system -- the archetype of ethereal ring systems -- consists of at least three components: the main ring, the vertically extended halo and the gossamer ring(s). The small moonlets Thebe and Amalthea orbit Jupiter within the gossamer ring region and structure in the intensity obtained from imaging observations indicates that these moons are the dominant sources of the gossamer ring material. The current picture implies that particles ejected from a source moon evolve inward under the Poynting-Robertson drag. Beyond Thebe's orbit, a very faint outward extension of the gossamer ring has also been observed which is not yet explained. Typical grain radii derived from optical imaging are a few micrometers. In November 2002 the Galileo spacecraft traversed the gossamer ring for the first time and had a close flyby at Amalthea. With the in-situ dust detector on board, dust measurements were collected throughout the gossamer ring and close to Amalthea. Several hundred impacts of dust grains were recorded and the data sets (impact charges, rise times, impact directions, etc.) of about 70 impacts were transmitted to Earth. In-situ dust measurements provide information about the physical properties of the dust environment not accessible with imaging techniques. They directly provide dust spatial densities along the spacecraft trajectory as well as grain sizes and impact speeds. This allows to test and refine current models of ring particle dynamics (see D. P. Hamilton et al., this conference). In particular, the direct measurement of grain sizes and dust spatial density in different regions of the gossamer ring allow to better constrain the forces dominating the grains' dynamics. The Galileo measurements in Jupiter's gossamer ring pave the way towards the in-situ dust measurements with Cassini in Saturn's E ring beginning in 2004.

  13. Galileo in-situ dust measurements in Jupiter's Gossamer Rings

    NASA Astrophysics Data System (ADS)

    Krueger, H.; Grün, E.; Hamilton, D. P.

    2003-05-01

    Jupiter's ring system -- the archetype of ethereal ring systems -- consists of at least three components: the main ring, the vertically extended halo and the gossamer ring(s). The small moonlets Thebe and Amalthea orbit Jupiter within the gossamer ring region and structure in the intensity obtained from imaging observations indicates that these moons are the dominant sources of the gossamer ring material. The current picture implies that particles ejected from a source moon evolve inward under the Poynting-Robertson drag. Beyond Thebe's orbit, a very faint outward extension of the gossamer ring has also been observed which is not yet explained. Typical grain radii derived from optical imaging are a few micrometers. In November 2002 the Galileo spacecraft traversed the gossamer ring for the first time and had a close flyby at Amalthea. With the in-situ dust detector on board, dust measurements were collected throughout the gossamer ring and close to Amalthea. Several hundred impacts of dust grains were recorded and the data sets (impact charges, rise times, impact directions, etc.) of about 90 impacts were transmitted to Earth. In-situ dust measurements provide information about the physical properties of the dust environment not accessible with imaging techniques. They directly provide dust spatial densities along the spacecraft trajectory as well as grain sizes and impact speeds. This allows to test and refine current models of ring particle dynamics (see D. P. Hamilton et al., this conference). In particular, the direct measurement of grain sizes and dust spatial density in different regions of the gossamer ring allow to better constrain the forces dominating the grains' dynamics. The Galileo measurements in Jupiter's gossamer ring pave the way towards the in-situ dust measurements with Cassini in Saturn's E ring beginning in 2004.

  14. A 'Moving' Jupiter Global Map (Animation)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Long Range Reconnaissance Imager (LORRI) on New Horizons has acquired six global maps of Jupiter as the spacecraft approaches the giant planet for a close encounter at the end of February. The high-resolution camera acquired each of six observation 'sets' as a series of individual pictures taken one hour apart, covering a full 10-hour rotation of Jupiter. The LORRI team at the Johns Hopkins University Applied Physics Laboratory (APL) reduced the sets to form six individual maps in a simple rectangular projection. These six maps were then combined to make the movie.

    The table below shows the dates and the ranges from Jupiter at which these six sets of observations were acquired. Even for the latest set of images taken January 21-22, from 60.5 million kilometers (37.6 million miles), New Horizons was still farther from Jupiter than the average distance of Mercury from the Sun. At that distance from Jupiter, a single LORRI picture resolution element amounts to 300 kilometers (186 miles) on Jupiter.

    Many features seen in Jupiter's atmosphere are giant storm clouds. The Little Red Spot, which LORRI will image close-up on February 27, is the target-like feature located near 30 degrees South and 230 degrees West; this storm is larger than the Earth. The even larger Great Red Spot is seen near 20 degrees South and 320 degrees West. The counterclockwise rotation of the clouds within the Great Red Spot can be seen. The westward drift of the Great Red Spot is easily seen in the movie, as is the slower drift, in the opposite direction, of the Little Red Spot. The storms of Jupiter are not fixed in location relative to each other or relative to any solid surface below, because Jupiter is a fluid planet without a solid surface.

    Also, dramatic changes are seen in the series of bright plume-like clouds encircling the planet between 0 and 10 degrees North. Scientists believe these result from an enormous atmospheric wave with rising air, rich in ammonia that

  15. JUPITER AS A GIANT COSMIC RAY DETECTOR

    SciTech Connect

    Rimmer, P. B.; Stark, C. R.; Helling, Ch.

    2014-06-01

    We explore the feasibility of using the atmosphere of Jupiter to detect ultra-high-energy cosmic rays (UHECRs). The large surface area of Jupiter allows us to probe cosmic rays of higher energies than previously accessible. Cosmic ray extensive air showers in Jupiter's atmosphere could in principle be detected by the Large Area Telescope (LAT) on the Fermi observatory. In order to be observed, these air showers would need to be oriented toward the Earth, and would need to occur sufficiently high in the atmosphere that the gamma rays can penetrate. We demonstrate that, under these assumptions, Jupiter provides an effective cosmic ray ''detector'' area of 3.3 × 10{sup 7} km{sup 2}. We predict that Fermi-LAT should be able to detect events of energy >10{sup 21} eV with fluence 10{sup –7} erg cm{sup –2} at a rate of about one per month. The observed number of air showers may provide an indirect measure of the flux of cosmic rays ≳ 10{sup 20} eV. Extensive air showers also produce a synchrotron signature that may be measurable by Atacama Large Millimeter/submillimeter Array (ALMA). Simultaneous observations of Jupiter with ALMA and Fermi-LAT could be used to provide broad constraints on the energies of the initiating cosmic rays.

  16. Generation of lightning in Jupiter's water cloud.

    PubMed

    Gibbard, S; Levy, E H; Lunine, J I

    1995-12-01

    Lightning is a familiar feature of storms on the Earth, and has also been seen on Jupiter and inferred indirectly to occur on Venus and Neptune. On Jupiter, lightning may be important as a source of energy to drive chemical reactions in the atmosphere, perhaps determining the abundances of molecules such as CO, HCN and C2H2. Lightning may be generated in Jupiter's water clouds by a mechanism similar to that which operates in terrestrial thunderstorms. Here we investigate the development of lightning by modelling the thunderstorm separation of electrical charge on precipitating ice particles at varying depths in Jupiter's atmosphere. We find that lightning can indeed be generated in the jovian water clouds, and that--in agreement with estimates from the analysis of Voyager images--it is most likely to occur at the 3- or 4-bar pressure level. Our model also predicts that a condensed-water abundance in the range of at least 1-2 g m-3 is required for lightning to occur in jovian thunderstorms--a prediction that may be tested when the Galileo probe arrives at Jupiter on 7 December 1995.

  17. Generation of lightning in Jupiter's water cloud.

    PubMed

    Gibbard, S; Levy, E H; Lunine, J I

    1995-12-01

    Lightning is a familiar feature of storms on the Earth, and has also been seen on Jupiter and inferred indirectly to occur on Venus and Neptune. On Jupiter, lightning may be important as a source of energy to drive chemical reactions in the atmosphere, perhaps determining the abundances of molecules such as CO, HCN and C2H2. Lightning may be generated in Jupiter's water clouds by a mechanism similar to that which operates in terrestrial thunderstorms. Here we investigate the development of lightning by modelling the thunderstorm separation of electrical charge on precipitating ice particles at varying depths in Jupiter's atmosphere. We find that lightning can indeed be generated in the jovian water clouds, and that--in agreement with estimates from the analysis of Voyager images--it is most likely to occur at the 3- or 4-bar pressure level. Our model also predicts that a condensed-water abundance in the range of at least 1-2 g m-3 is required for lightning to occur in jovian thunderstorms--a prediction that may be tested when the Galileo probe arrives at Jupiter on 7 December 1995. PMID:8524392

  18. Comprehensive Optical Coverage of Jupiter for Spectral Comparison with NH4SH

    NASA Astrophysics Data System (ADS)

    Thelen, Alexander E.; Chanover, Nancy; Loeffler, Mark; Hudson, Reggie; Simon, Amy

    2015-11-01

    The distinct regions in Jupiter's atmosphere - comprised of belts, zones, storms, and the Great Red Spot - are thought to be colored by unidentified chemical compounds called chromophores. These molecules, created through Jupiter's complex atmospheric chemistry, may be responsible for the spectral slope and lack of features in the blue (shortwards of 500 nm) portion of Jupiter's optical spectrum. Though many candidate compounds have been proposed - such as ammonium hydrosulfide (NH4SH) - the identity of the coloring agent (or agents) remains elusive due to the sparse history of laboratory experiments conducted at appropriate temperatures and pressures for Jovian conditions. To build on previous ground-based observations of Jupiter in the optical, we have obtained spectra with the Dual Imaging Spectrograph - mounted on the Astrophysical Research Consortium 3.5-meter telescope at Apache Point Observatory - over a wide portion of the visible spectrum (~380-880 nm) by utilizing multiple central wavelength settings. These observations, taken during February, 2013 and April, 2015, cover multiple latitudinal regions on Jupiter, including the Great Red Spot. In this study, we present the spectral comparison of various regions in the Jovian atmosphere with data taken at the Cosmic Ice Laboratory at NASA’s Goddard Space Flight Center. By exposing thin films of NH4SH to varying amounts of ionizing radiation at Jovian temperature conditions, we can analyze the color and spectral changes of the ice. This enables us to evaluate NH4SH as a candidate chromophore through comparisons of spectral slope and features found in ground-based optical spectra of Jupiter. This work was supported by NASA’s Outer Planets Research Program through grant number NNX12AJ14G.

  19. HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Sing, D. K.; Wakeford, H. R.; Showman, A. P.; Nikolov, N.; Fortney, J. J.; Burrows, A. S.; Ballester, G. E.; Deming, D.; Aigrain, S.; Désert, J.-M.; Gibson, N. P.; Henry, G. W.; Knutson, H.; Lecavelier des Etangs, A.; Pont, F.; Vidal-Madjar, A.; Williamson, M. W.; Wilson, P. A.

    2015-01-01

    We present Hubble Space Telescope optical and near-IR transmission spectra of the transiting hot-Jupiter WASP-31b. The spectrum covers 0.3-1.7 μm at a resolution R ˜ 70, which we combine with Spitzer photometry to cover the full-optical to IR. The spectrum is dominated by a cloud deck with a flat transmission spectrum which is apparent at wavelengths > 0.52 μm. The cloud deck is present at high altitudes and low pressures, as it covers the majority of the expected optical Na line and near-IR H2O features. While Na I absorption is not clearly identified, the resulting spectrum does show a very strong potassium feature detected at the 4.2σ confidence level. Broadened alkali wings are not detected, indicating pressures below ˜10 mbar. The lack of Na and strong K is the first indication of a sub-solar Na/K abundance ratio in a planetary atmosphere (ln[Na/K] = -3.3 ± 2.8), which could potentially be explained by Na condensation on the planet's night side, or primordial abundance variations. A strong Rayleigh scattering signature is detected at short wavelengths, with a 4σ significant slope. Two distinct aerosol size populations can explain the spectra, with a smaller sub-micron size grain population reaching high altitudes producing a blue Rayleigh scattering signature on top of a larger, lower lying population responsible for the flat cloud deck at longer wavelengths. We estimate that the atmospheric circulation is sufficiently strong to mix micron size particles upwards to the required 1-10 mbar pressures, necessary to explain the cloud deck. These results further confirm the importance of clouds in hot Jupiters, which can potentially dominate the overall spectra and may alter the abundances of key gaseous species.

  20. The Icy Moons of Jupiter

    NASA Astrophysics Data System (ADS)

    Greenberg, Richard

    The Galilean satellites formed in a nebula of dust and gas that surrounded Jupiter toward the end of the formation of the giant planet itself. Their diverse initial compositions were determined by conditions in the circum-jovian nebula, just as the planets' initial properties were governed by their formation within the circum-solar nebula. The Galilean satellites subsequently evolved under the complex interplay of orbital and geophysical processes, which included the effects of orbital resonances, tides, internal differentiation, and heat. The history and character of the satellites can be inferred from consideration of the formation of planets and the satellites, from studies of their plausible orbital evolution, from measurements of geophysical properties, especially gravitational and magnetic fields, from observations of the compositions and geological structure of their surfaces, and from geophysical modeling of the processes that can relate these lines of evidence. The three satellites with large water-ice components, Europa, Ganymede, and Callisto are very different from one another as a result of the ways that these processes have played out in each case. Europa has a deep liquid-water ocean with a thin layer of surface ice, Ganymede and Callisto likely have relatively thin liquid water layers deep below their surfaces, and Callisto remains only partially differentiated, with rock and ice mixed through much of its interior. A tiny inner satellite, Amalthea, also appears to be largely composed of ice. Each of these moons is fascinating in its own right, and the ensemble provides a powerful set of constraints on the processes that led to their formation and evolution.

  1. Did Jupiter's core form in the innermost parts of the Sun's protoplanetary disc?

    NASA Astrophysics Data System (ADS)

    Raymond, Sean N.; Izidoro, Andre; Bitsch, Bertram; Jacobson, Seth A.

    2016-05-01

    Jupiter's core is generally assumed to have formed beyond the snow line. Here we consider an alternative scenario that Jupiter's core may have accumulated in the innermost part of the protoplanetary disc. A growing body of research suggests that small particles (`pebbles') continually drift inward through the disc. If a fraction of drifting pebbles is trapped at the inner edge of the disc, several Earth-mass cores can quickly grow. Subsequently, the core may migrate outward beyond the snow line via planet-disc interactions. Of course, to reach the outer Solar system Jupiter's core must traverse the terrestrial planet-forming region. We use N-body simulations including synthetic forces from an underlying gaseous disc to study how the outward migration of Jupiter's core sculpts the terrestrial zone. If the outward migration is fast (τmig ˜ 104 yr), the core simply migrates past resident planetesimals and planetary embryos. However, if its migration is slower (τmig ˜ 105 yr) the core clears out solids in the inner disc by shepherding objects in mean motion resonances. In many cases, the disc interior to 0.5-1 AU is cleared of embryos and most planetesimals. By generating a mass deficit close to the Sun, the outward migration of Jupiter's core may thus explain the absence of terrestrial planets closer than Mercury. Jupiter's migrating core often stimulates the growth of another large (˜Earth-mass) core - that may provide a seed for Saturn's core - trapped in an exterior resonance. The migrating core also may transport a fraction of terrestrial planetesimals, such as the putative parent bodies of iron meteorites, to the asteroid belt.

  2. Simulation of What Juno Will 'See' From Jupiter Orbit

    NASA Video Gallery

    This animation shows how Jupiter will appear to the camera onboard NASA's Juno mission, called JunoCam, as the spacecraft goes through an orbit. Juno will circle Jupiter every 11 days from an ellip...

  3. Heating of Jupiter's upper atmosphere above the Great Red Spot

    NASA Astrophysics Data System (ADS)

    O'Donoghue, James; Moore, Luke; Stallard, Tom; Melin, Henrik

    2016-10-01

    Measured upper-atmospheric, mid-to-low latitude temperatures of the giant planets are hundreds of degrees warmer than simulations based on solar heating alone can explain. Modelling studies, focused on additional sources of heating, have been so far unable to resolve this significant model-data discrepancy. Equatorward transport of energy from the hot auroral regions was expected to heat low latitude regions; instead, models have demonstrated that auroral energy is trapped at high latitudes, a consequence of the strong Coriolis forces on these rapidly rotating planets. Wave heating, driven from below, represents another potential source of upper-atmospheric heating. Using data taken in 2012 by the ground-based NASA IRTF, we found through observations of the H3+ ion that the upper atmosphere above Jupiter's Great Red Spot (GRS) - the largest storm in the solar system - is hundreds of degrees hotter than anywhere else on the planet. Specifically, the result shows that the northern region of the spot was over 1600 K, and that background temperatures away from the spot are ~850 K. The hotspot, by process of elimination, must be heated from below, and this detection is therefore strong evidence for coupling between Jupiter's lower and upper atmospheres, likely the result of upward propagating acoustic and/or gravity waves. Our results indicate that the lower atmosphere may yet play an important role in resolving the giant planet 'energy crisis'.

  4. On the abundance of non-cometary HCN on Jupiter.

    PubMed

    Moses, Julianne I; Visscher, Channon; Keane, Thomas C; Sperier, Aubrey

    2010-01-01

    Using one-dimensional thermochemical/photochemical kinetics and transport models, we examine the chemistry of nitrogen-bearing species in the Jovian troposphere in an attempt to explain the low observational upper limit for HCN. We track the dominant mechanisms for interconversion of N2-NH3 and HCN-NH3 in the deep, high-temperature troposphere and predict the rate-limiting step for the quenching of HCN at cooler tropospheric altitudes. Consistent with some other investigations that were based solely on time-scale arguments, our models suggest that transport-induced quenching of thermochemically derived HCN leads to very small predicted mole fractions of hydrogen cyanide in Jupiter's upper troposphere. By the same token, photochemical production of HCN is ineffective in Jupiter's troposphere: CH4-NH3 coupling is inhibited by the physical separation of the CH4 photolysis region in the upper stratosphere from the NH3 photolysis and condensation region in the troposphere, and C2H2-NH3 coupling is inhibited by the low tropospheric abundance of C2H2. The upper limits from infrared and submillimetre observations can be used to place constraints on the production of HCN and other species from lightning and thundershock sources. PMID:21302544

  5. Coupled Radiative-Dynamical GCM Simulations of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Showman, Adam P.; Fortney, J. J.; Lian, Y.; Marley, M. S.; Knutson, H. A.; Charbonneau, D.

    2008-09-01

    The stellar flux incident on hot Jupiters -- gas giants within 0.1 AU of their stars -- is expected to drive an atmospheric circulation that shapes the day-night temperature difference, infrared lightcurves, spectrum, albedo, and atmospheric composition. Although several atmospheric-dynamics models of these objects have been published, all adopt simplified heating/cooling schemes that preclude robust predictions for the 3D temperature patterns, spectra, and lightcurves. Here, we present cloud-free simulations of hot Jupiters from the first 3D general circulation model (GCM) that couples the atmospheric dynamics to a realistic representation of radiative transfer. We emphasize HD189733b and HD209458b, which are the best observationally constrained hot Jupiters and which represent an interesting pair because one (HD209458b) appears to have a dayside stratosphere while the other (HD189733b) does not. Our simulations develop large day-night temperature contrasts and winds reaching speeds of several km/sec. A prograde equatorial jet forms with retrograde flows at higher latitudes, which leads to an eastward displacement of the hottest regions from the substellar point and coldest regions from the antistellar point. For HD189733b, our predicted lightcurves compare favorably with lightcurves observed at 8 and 24 microns with the Spitzer Space Telescope, including the modest day-night flux variation and offset of the flux peak from the time of secondary eclipse. The simulated temperatures decrease with altitude, leading to a spectrum dominated by absorption features. For HD209458b, inclusion of TiO and VO opacity leads to a dayside thermal inversion layer (stratosphere) where temperatures rise above 2000 K, consistent with suggestions offered to explain the observed secondary-eclipse spectrum. Interestingly, however, our 3D models do not match the observed spectrum, which suggests that our simulated stratosphere does not yet have the correct properties (e.g., altitude and

  6. Dayside-Nightside Temperature Differences in Hot Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Showman, Adam P.

    2015-12-01

    The infrared phase curves of low-eccentricity transiting hot Jupiters show a trend of increasing flux amplitude, or increasing day-night temperature difference, with increasing equilibrium temperature. Here we utilize atmospheric circulation modeling and analytic theory to understand this trend, and the more general question: what processes control heat redistribution in tidally-locked giant planet atmospheres? We performed a wide range of 3D numerical simulations of the atmospheric circulation with simplified forcing, and constructed an analytic theory that explains the day-night temperature differences in these simulations over a wide parameter space. Our analytic theory shows that day-night temperature differences in tidally-locked planet atmospheres are mediated by wave propagation. If planetary-scale waves are free to propagate longitudinally, they will efficiently flatten isentropes and lessen day-night temperature differences. If these waves are damped, the day-night temperature differences will necessarily be larger. We expect that wave propagation in hot Jupiter atmospheres can be damped in two ways: by either radiative cooling or frictional drag. Both of these processes increase in efficacy with increasing equilibrium temperature, as radiative cooling is directly related to the cube of temperature and magnetically-induced (Lorentz) drag becomes stronger with increasing partial ionization and hence temperature. We find that radiative cooling plays the largest role in damping wave propagation and hence plays the biggest role in controlling day-night temperature differences. As a result, day-night temperature differences in hot Jupiter atmospheres decrease with increasing pressure and increase with increasing stellar flux. One can apply this result to phase curve observations of individual hot Jupiters in multiple bandpasses, as varying flux amplitudes between wavelengths implies that different photospheric pressure levels are being probed. Namely, a larger

  7. Atmospheric Motion in Jupiter's Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    2000-01-01

    True-color (left) and false-color (right) mosaics of Jupiter's northern hemisphere between 10 and 50 degrees latitude. Jupiter's atmospheric motions are controlled by alternating eastward and westward bands of air between Jupiter's equator and polar regions. The direction and speed of these bands influences the color and texture of the clouds seen in this mosaic. The high and thin clouds are represented by light blue, deep clouds are reddish, and high and thick clouds are white. A high haze overlying a clear, deep atmosphere is represented by dark purple. This image was taken by NASA's Galileo spacecraft on April 3, 1997 at a distance of 1.4 million kilometers (.86 million miles).

  8. Principal components analysis of Jupiter VIMS spectra

    USGS Publications Warehouse

    Bellucci, G.; Formisano, V.; D'Aversa, E.; Brown, R.H.; Baines, K.H.; Bibring, J.-P.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2004-01-01

    During Cassini - Jupiter flyby occurred in December 2000, Visual-Infrared mapping spectrometer (VIMS) instrument took several image cubes of Jupiter at different phase angles and distances. We have analysed the spectral images acquired by the VIMS visual channel by means of a principal component analysis technique (PCA). The original data set consists of 96 spectral images in the 0.35-1.05 ??m wavelength range. The product of the analysis are new PC bands, which contain all the spectral variance of the original data. These new components have been used to produce a map of Jupiter made of seven coherent spectral classes. The map confirms previously published work done on the Great Red Spot by using NIMS data. Some other new findings, presently under investigation, are presented. ?? 2004 Published by Elsevier Ltd on behalf of COSPAR.

  9. Solar wind interaction with Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Delamere, P. A.; Bagenal, F.

    2009-12-01

    We suggest that the solar wind interaction with Jupiter's magnetosphere is dominated by viscous processes at the magnetopause boundary rather than a coherent reconnection-driven Dungey cycle. In particular, we show that shear flow-driven instabilities (e.g. Kelvin-Helmholtz) on Jupiter's magnetopheric flank can account for observations of: 1) flux tubes substantially depleted of energetic particles in regions outside of the plasmasheet, 2) anti-sunward flow in the dawnside ionosphere, 3) an aurorally active polar cap, and 4) a long magnetotail extending ~4 AU downstream. A preliminary analysis of the Kelvin-Helmholtz instability (KHI) as a function of local time will be presented along with initial two-dimensional hybrid code simulations of KHI at Jupiter's magnetopause boundary.

  10. Radiative-dynamical equilibrium states for Jupiter

    NASA Technical Reports Server (NTRS)

    Trafton, L. M.; Stone, P. H.

    1974-01-01

    In order to obtain accurate estimates of the radiative heating that drives motions in Jupiter's atmosphere, previous radiative equilibrium calculations are improved by including the NH3 opacities and updated results for the pressure-induced opacities. These additions increase the radiative lapse rate near the top of the statically unstable region and lead to a fairly constant radiative lapse rate below the tropopause. The radiative-convective equilibrium temperature structure consistent with these changes is calculated, but it differs only slightly from earlier calculations. The radiative equilibrium calculations are used to calculate whether equilibrium states can occur on Jupiter which are similar to the baroclinic instability regimes on the earth and Mars. The results show that Jupiter's dynamical regime cannot be of this kind, except possibly at very high latitudes, and that its regime must be a basically less stable one than this kind.

  11. Thermal tides on a hot Jupiter

    NASA Astrophysics Data System (ADS)

    Gu, P.-G.; Hsieh, H.-F.

    2011-07-01

    Following the linear analysis laid out by Gu & Ogilvie 2009 (hereafter GO09), we investigate the dynamical response of a non-synchronized hot Jupiter to stellar irradiation. Besides the internal and Rossby waves considered by GO09, we study the Kelvin waves excited by the diurnal Fourier harmonic of the prograde stellar irradiation. We also present a 2-dimensional plot of internal waves excited by the semi-diurnal component of the stellar irradiation and postulate that thermal bulges may arise in a hot Jupiter. Whether our postulation is valid and is consistent with the recent results from Arras & Socrates (2009b) requires further investigation.

  12. Radiation belts of jupiter: a second look.

    PubMed

    Fillius, R W; McIlwain, C E; Mogro-Campero, A

    1975-05-01

    The outbound leg of the Pioneer 11 Jupiter flyby explored a region farther from the equator than that traversed by Pioneer 10, and the new data require modification or augmentation of the magnetodisk model based on the Pioneer 10 flyby. The inner moons of Jupiter are sinks of energetic particles and sometimes sources. A large spike of particles was found near lo. Multiple peaks occurred in the particle fluxes near closest approach to the planet; this structure may be accounted for by a complex magnetic field configuration. The decrease in proton flux observed near minimum altitude on the Pioneer 10 flyby appears attributable to particle absorption by Amalthea.

  13. HUBBLE PROVIDES COMPLETE VIEW OF JUPITER'S AURORAS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has captured a complete view of Jupiter's northern and southern auroras. Images taken in ultraviolet light by the Space Telescope Imaging Spectrograph (STIS) show both auroras, the oval- shaped objects in the inset photos. While the Hubble telescope has obtained images of Jupiter's northern and southern lights since 1990, the new STIS instrument is 10 times more sensitive than earlier cameras. This allows for short exposures, reducing the blurring of the image caused by Jupiter's rotation and providing two to five times higher resolution than earlier cameras. The resolution in these images is sufficient to show the 'curtain' of auroral light extending several hundred miles above Jupiter's limb (edge). Images of Earth's auroral curtains, taken from the space shuttle, have a similar appearance. Jupiter's auroral images are superimposed on a Wide Field and Planetary Camera 2 image of the entire planet. The auroras are brilliant curtains of light in Jupiter's upper atmosphere. Jovian auroral storms, like Earth's, develop when electrically charged particles trapped in the magnetic field surrounding the planet spiral inward at high energies toward the north and south magnetic poles. When these particles hit the upper atmosphere, they excite atoms and molecules there, causing them to glow (the same process acting in street lights). The electrons that strike Earth's atmosphere come from the sun, and the auroral lights remain concentrated above the night sky in response to the 'solar wind,' as Earth rotates underneath. Earth's auroras exhibit storms that extend to lower latitudes in response to solar activity, which can be easily seen from the northern U. S. But Jupiter's auroras are caused by particles spewed out by volcanoes on Io, one of Jupiter's moons. These charged particles are then magnetically trapped and begin to rotate with Jupiter, producing ovals of auroral light centered on Jupiter's magnetic poles in both the day and night skies

  14. HCN and chromophore formation on Jupiter

    NASA Astrophysics Data System (ADS)

    Ferris, J. P.; Ishikawa, Y.

    1987-04-01

    The formation of HCN and chromophores are two of the major unsolved problems of the atmospheric chemistry of Jupiter. The question to be dealt with is the same in each case: how can these unsaturated organic compounds be formed in the highly reducing atmosphere (89% H2) present on Jupiter? The photolysis of ammonia/acetylene mixtures provides an answer to this question. The authors report the formation of both HCN and chromophores along with experimental data which support the premise that this photochemical process provides a route for the formation of both substances.

  15. Extreme Environments Technologies for Probes to Venus and Jupiter

    NASA Technical Reports Server (NTRS)

    Balint, Tibor S.; Kolawa, Elizabeth A.; Peterson, Craig E.; Cutts, James A.; Belz, Andrea P.

    2007-01-01

    This viewgraph presentation reviews the technologies that are used to mitigate extreme environments for probes at Venus and Jupiter. The contents include: 1) Extreme environments at Venus and Jupiter; 2) In-situ missions to Venus and Jupiter (past/present/future); and 3) Approaches to mitigate conditions of extreme environments for probes with systems architectures and technologies.

  16. Jupiter: Giant of the solar system. [its solar orbits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

  17. Rapid Response: Unexpected Jupiter Impact

    NASA Astrophysics Data System (ADS)

    Simon-Miller, Amy

    2009-07-01

    On 3 June 2010, amateur astronomers A. Wesley and C. Go independently captured observations of an impact on Jupiter: the bright flash of an impact itself, not the dark aftermath as seen in 2009. This event was completely unexpected given the recent impact in 2009, and contradicts recently revised predictions of jovian impact rates. Three circumstances make this 2009 event unique: first, the event was captured on video; second, it was on the jovian day-side and hence fully visible from Earth; and third, it was at low latitude {i.e., favorably placed on the planet}. These factors will permit a lightcurve to be extracted, which is critical for determining the energy of the explosion and hence the size of the impacting body {not available for the 2009 event and available for only a few 1994 events by Galileo}. As of this writing, no dark impact site has been detected with telescopes of any aperture, including the Gemini North telescope. Hubble may be the only facility with high enough spatial resolution to detect the 2010 impact site. If Hubble images show a site, then the body's trajectory might be obtainable. If no site is detected, then Hubble will confirm that this is the first observation of a meteor on another atmosphere-bearing planet. If an event of this size occurred on Earth, it would be likely be termed a Type 1 Low-Altitude Airburst, like Tunguska or larger. Thus, this new event could become the best-observed analogue of a terrestrial airburst of the size that dominates the impact threat to humans. The observations we propose should provide independent constraints on penetration depth and atmospheric effects. This data will strongly inform our understanding of terrestrial airbursts and allow better quantification of the associated threat. We request a single orbit to image the impact latitude on the planet's central meridian. Of critical importance are Hubble's unique UV sensitivity {critical for assessing aspects of the 2009 impact, and not obtainable from

  18. Spatial distribution of water in the stratosphere of Jupiter from observations with the Herschel space observatory

    NASA Astrophysics Data System (ADS)

    Cavalié, T.; Feuchtgruber, H.; Lellouch, E.; de Val-Borro, M.; Jarchow, C.; Moreno, R.; Hartogh, P.; Orton, G.; Greathouse, T. K.; Billebaud, F.; Dobrijevic, M.; Lara, L. M.; Gonzalez, A.; Sagawa, H.

    2013-09-01

    Water in the atmospheres of the outer planets has both an internal and an external source (e.g., [1] and [2] for Jupiter). These sources are separated by a condensation layer, the tropopause cold trap, which acts as a transport barrier between the troposphere and the stratosphere. Thus, the water vapor observed by the Infrared Space Observatory (ISO) in the stratosphere of the giant planets has an external origin [3]. This external supply of water may have several sources: (i) a permanent flux from interplanetary dust particles produced from asteroid collisions and from comet activity [4], (ii) local sources from planetary environments (rings, satellites) [5], (iii) cometary "Shoemaker-Levy 9 (SL9) type" impacts [6]. In the past 15 years, several studies suggested that water in the stratosphere of Jupiter originated from the SL9 comet impacts in July 1994, but a direct proof was missing. We will report the first high S/N spatially resolved mapping observations of water in Jupiter's stratosphere carried out with the Heterodyne Instrument for the Far Infrared (HIFI) [7] and Photodetector Array Camera and Spectrometer (PACS) [8] instruments onboard the ESA Herschel Space Observatory [9]. These observations have been obtained in the framework of the Guaranteed Time Key Program "Water and related chemistry in the Solar System", also known as "Herschel Solar System Observations" (HssO) [10]. In parallel, we have monitored Jupiter's stratospheric temperature with the NASA Infrared Telescope Facility (IRTF) to separate temperature from water variability. We will present the results recently published by our team [11]. Water is found to be restricted to pressures lower than 2mbar. Its column density decreases by a factor of 2-3 between southern and northern latitudes (see Fig. 1), consistently between the HIFI and the PACS 66.4μm maps. Latitudinal temperature variability cannot explain the global north-south asymmetry in the water maps. From the latitudinal and vertical

  19. EVIDENCE FOR THE TIDAL DESTRUCTION OF HOT JUPITERS BY SUBGIANT STARS

    SciTech Connect

    Schlaufman, Kevin C.; Winn, Joshua N. E-mail: jwinn@mit.edu

    2013-08-01

    Tidal transfer of angular momentum is expected to cause hot Jupiters to spiral into their host stars. Although the timescale for orbital decay is very uncertain, it should be faster for systems with larger and more evolved stars. Indeed, it is well established that hot Jupiters are found less frequently around subgiant stars than around main-sequence stars. However, the interpretation of this finding has been ambiguous, because the subgiants are also thought to be more massive than the F- and G-type stars that dominate the main-sequence sample. Consequently, it has been unclear whether the absence of hot Jupiters is due to tidal destruction or inhibited formation of those planets around massive stars. Here we show that the Galactic space motions of the planet-hosting subgiant stars demand that on average they be similar in mass to the planet-hosting main-sequence F- and G-type stars. Therefore the two samples are likely to differ only in age, and provide a glimpse of the same exoplanet population both before and after tidal evolution. As a result, the lack of hot Jupiters orbiting subgiants is clear evidence for their tidal destruction. Questions remain, though, about the interpretation of other reported differences between the planet populations around subgiants and main-sequence stars, such as their period and eccentricity distributions and overall occurrence rates.

  20. Weakening of Jupiter's main auroral emission during January 2014

    NASA Astrophysics Data System (ADS)

    Badman, S. V.; Bonfond, B.; Fujimoto, M.; Gray, R. L.; Kasaba, Y.; Kasahara, S.; Kimura, T.; Melin, H.; Nichols, J. D.; Steffl, A. J.; Tao, C.; Tsuchiya, F.; Yamazaki, A.; Yoneda, M.; Yoshikawa, I.; Yoshioka, K.

    2016-02-01

    In January 2014 Jupiter's FUV main auroral oval decreased its emitted power by 70% and shifted equatorward by ˜1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in auroral current density rather than electron energy. This could be caused by a decrease in the source electron density, an order of magnitude increase in the source electron thermal energy, or a combination of these. Both can be explained either by expansion of the magnetosphere or by an increase in the inward transport of hot plasma through the middle magnetosphere and its interchange with cold flux tubes moving outward. In the latter case the hot plasma could have increased the electron temperature in the source region and produced the intense, low-latitude features, while the increased cold plasma transport rate produced the shift of the main oval.

  1. Hot Jupiters from Coplanar High-eccentricity Migration

    NASA Astrophysics Data System (ADS)

    Petrovich, Cristobal

    2014-11-01

    The question of what mechanism is responsible for delivering giant planets into short-periods orbits (<10 days), the so-called hot Jupiters (HJs), is one of the fundamental unresolved questions in planet formation. In this talk, I propose that most HJs are formed through the secular interaction of two planets in eccentric and nearly coplanar orbits and tidal dissipation due to the host star, mechanism which I term coplanar high-eccentricity migration (CHEM). I will show that the HJs formed by CHEM can well-reproduce the observed period distribution, as well as explain why most HJs have low stellar obliquities. I further provide with testable predictions regarding the properties (e.g., masses and orbital periods) of the outer perturber and formation timescales in HJ systems.

  2. Photochemistry of Methane in Model Atmospheres of Jupiter and Titan

    NASA Technical Reports Server (NTRS)

    Bersohn, Richard

    2000-01-01

    The two central findings were 1) hydrogen atoms and hydrogen molecules photodissociated from methane are relatively richer in H than in D in other words deuterium atoms have a greater probability of remaining attached to the carbon atom. Titan, a moon of Saturn has an atmosphere which is largely nitrogen but also contains about 3% methane as well as smaller amounts of C2 and C3 hydrocarbons. If all these hydrocarbons are of biological origin, the isotopic scrambling occurring in living organisms would result in equal D atom abundances. On the other hand, if the higher hydrocarbons are derived from methane by photodissociation of methane, they should be richer in D than methane. Precise values for the enrichment were derived from our photochemical data. 2) When methane is dissociated by vuv light, methylene is produced in a singlet state. This explains why the higher hydrocarbons are sparse on Jupiter but relatively rich on Titan.

  3. On the Radius Anomaly of Hot Jupiters: Reexamination of the Possibility and Impact of Layered Convection

    NASA Astrophysics Data System (ADS)

    Kurokawa, Hiroyuki; Inutsuka, Shu-ichiro

    2015-12-01

    Observations have revealed that a significant number of hot Jupiters have anomalously large radii. Layered convection induced by compositional inhomogeneity has been proposed to account for the radius anomaly of hot Jupiters. To reexamine the impact of the compositional inhomogeneity, we perform an evolutionary calculation by determining the convection regime at each evolutionary time step according to the criteria from linear analyses. It is shown that the impact is limited in the case of the monotonic gradient of heavy-element abundance. The layered convection is absent for the first 1 Gyr from the formation of hot Jupiters, and instead overturning convection develops. The superadiabaticity of the temperature gradient is limited by the neutrally stable state for the Ledoux stability criterion. The effect of the increased mass of heavy elements essentially compensates the effect of the delayed contraction on the planetary radius caused by compositional inhomogeneity. In addition, even in the case where the layered convection is artificially imposed, this mechanism requires extremely thin layers (˜101-103 cm) to account for the observed radius anomaly. The long-term stability of such thin layers remains to be studied. Therefore, if the criteria adopted in this paper are adequate, it might be difficult to explain the inflated radii of hot Jupiters by the monotonic gradient of heavy-element abundance alone.

  4. Infrared studies of hydrocarbons on Jupiter

    NASA Astrophysics Data System (ADS)

    Kostiuk, T.; Espenak, F.; Mumma, M. J.; Romani, P.

    1989-05-01

    Measurements of ethane and ethylene emission lines on Jupiter were made using a dual CO2 laser heterodyne spectrometer. Retrieved abundances of these products of methane photolysis in the Jovian stratosphere were used to test existing photochemical models and to investigate a localized "hot spot" in the northern auroral region.

  5. JUPITER PROJECT - MERGING INVERSE PROBLEM FORMULATION TECHNOLOGIES

    EPA Science Inventory

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project seeks to enhance and build on the technology and momentum behind two of the most popular sensitivity analysis, data assessment, calibration, and uncertainty analysis programs used in envi...

  6. Baby Jupiters Must Gain Weight Fast

    NASA Technical Reports Server (NTRS)

    2009-01-01

    This photograph from NASA's Spitzer Space Telescope shows the young star cluster NGC 2362. By studying it, astronomers found that gas giant planet formation happens very rapidly and efficiently, within less than 5 million years, meaning that Jupiter-like worlds experience a growth spurt in their infancy.

  7. Dramatic Change in Jupiter's Great Red Spot

    NASA Technical Reports Server (NTRS)

    Simon, A. A.; Wong, M. H.; Rogers, J. H.; Orton, G. S.; de Pater, I.; Asay-Davis, X.; Carlson, R. W.; Marcus, P. S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features, having been continuously observed since the 1800's. It currently spans the smallest latitude and longitude size ever recorded. Here we show analyses of 2014 Hubble spectral imaging data to study the color, structure and internal dynamics of this long-live storm.

  8. Influence of solar activity on Jupiter's atmosphere

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.

    2016-05-01

    The influx of solar energy to different latitudes while Jupiter's orbital motion around the Sun varies significantly. This leads to a change in the optical and physical characteristics of its atmosphere. Analysis of the data for 1850-1991 on determination of the integral magnitude Mj Jupiter in the V filter, and a comparison with the changes of the Wolf numbers W, characterizing the variations of solar activity (SA) - showed that the change of Mj in maxima of the SA - has minima for odd, and maximums - for the even of SA cycles. That is, changing of the Jupiter brightness in visible light is much evident 22.3-year magnetic cycle, and not just about the 11.1-year cycle of solar activity. Analysis of the obtained in 1960-2015 data on the relative distribution of brightness along the central meridian of Jupiter, for which we calculated the ratio of the brightness Aj of northern to the southern part of the tropical and temperate latitudinal zones, allowed to approximate the change of Aj by sinusoid with a period of 11.91±0.07 earth years. Comparison of time variation of Aj from changes in the index of SA R, and the movement of the planet in its orbit - indicates the delay of response of the visible cloud layer in the atmosphere of the Sun's exposure mode for 6 years. This value coincides with the radiative relaxation of the hydrogen-helium atmosphere

  9. Jupiter Quest: A Path to Scientific Discovery.

    ERIC Educational Resources Information Center

    Bollman, Kelly A.; Rodgers, Mark H.; Mauller, Robert L.

    2001-01-01

    To experience the world of professional science, students must have access to the scientific community and be allowed to become real scientists. A partnership involving the National Aeronautics and Space Administration, the Jet Propulsion Laboratory, and the Lewis Center for Educational Research has produced Jupiter Quest, an engaging curriculum…

  10. The Voyager flights to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The results of the mini-Grand Tour to Jupiter and Saturn by the Voyager 1 and 2 spacecraft are highlighted. Features of the spacecraft are depicted including the 11 instruments designed to probe the planets and their magnetic environments, the rings of Saturn, the fleets of satellites escorting the planets, and the interplanetary medium. Major scientific discoveries relating to these phenomena are summarized.

  11. Jupiter Environmental Research & Field Studies Academy.

    ERIC Educational Resources Information Center

    Huttemeyer, Bob

    1996-01-01

    Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

  12. Jupiter Exploration: High Risk and High Rewards

    NASA Astrophysics Data System (ADS)

    Kite, Edwin S.

    2004-12-01

    Jupiter exploration is big science, and only the United States can afford self-contained missions to the gas giant and its four planet-sized moons. The Galileo spacecraft, which was recently flown into Jupiter to prevent it from contaminating Europa's ocean, cost $1.6 billion. Despite the failure of its High Gain Antenna (HGA), Galileo discovered briny, subsurface oceans on Europa, Ganymede, and Callisto; globally mapped all four Galilean moons; monitored Io's volcanic activity; carried out a 7-year study of the Jovian magnetosphere; and dropped an atmospheric probe into Jupiter's upper cloud layer. Of these achievements, the most significant is the indirect detection of a deep subsurface liquid-water layer on Europa [Pappalardo et al., 1999; Kivelson et al., 2000]. The case for a Europan ecosystem can be made [e.g., Marion et al., 2004], although it is important to remember the energetic and biogeochemical limits on putative Europan life [e.g., Soare et al., 2002]. Europa's low moment of inertia (0.346 +/- 0.005 MR2) suggests a silicate mantle below the ocean, permitting chemical exchanges between ocean and silicates, as occurs on Earth. Europa's surface is geologically young, likely emplaced 20-180 million years ago. Any recycling of surficial icy crust into the ocean could add oxygen, sulfur, and organic compounds, either impact-delivered or generated in situ by UV irradiation and the implantation of ionized particles from Jupiter's radiation belts.

  13. Jupiter in blue, ultraviolet and near infrared

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These three images of Jupiter, taken through the narrow angle camera of NASA's Cassini spacecraft from a distance of 77.6 million kilometers (48.2 million miles) on October 8, reveal more than is apparent to the naked eye through a telescope.

    The image on the left was taken through the blue filter. The one in the middle was taken in the ultraviolet. The one on the right was taken in the near infrared.

    The blue-light filter is within the part of the electromagnetic spectrum detectable by the human eye. The appearance of Jupiter in this image is, consequently, very familiar. The Great Red Spot (below and to the right of center) and the planet's well-known banded cloud lanes are obvious. The brighter bands of clouds are called zones and are probably composed of ammonia ice particles. The darker bands are called belts and are made dark by particles of unknown composition intermixed with the ammonia ice.

    Jupiter's appearance changes dramatically in the ultraviolet and near infrared images. These images are near negatives of each other and illustrate the way in which observations in different wavelength regions can reveal different physical regimes on the planet.

    All gases scatter sunlight efficiently at short wavelengths; this is why the sky appears blue on Earth. The effect is even more pronounced in the ultraviolet. The gases in Jupiter's atmosphere, above the clouds, are no different. They scatter strongly in the ultraviolet, making the deep banded cloud layers invisible in the middle image. Only the very high altitude haze appears dark against the bright background. The contrast is reversed in the near infrared, where methane gas, abundant on Jupiter but not on Earth, is strongly absorbing and therefore appears dark. Again the deep clouds are invisible, but now the high altitude haze appears relatively bright against the dark background. High altitude haze is seen over the poles and the equator.

    The Great Red Spot, prominent in all images, is

  14. The EJSM Jupiter-Europa Orbiter: Mission Overview

    NASA Astrophysics Data System (ADS)

    Pappalardo, R. T.; Clark, K.; Greeley, R.; Hendrix, A. R.; Tan-Wang, G.; Lock, R.; van Houten, T.; Ludwinski, J.; Petropoulis, A.; Jun, I.; Boldt, J.; Kinnison, J.

    2008-09-01

    Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, Galileo supplied fascinating new insights into that satellite's secrets. The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the Europa Jupiter System Mission (EJSM), an international mission with orbiters developed by NASA, ESA and possibly JAXA. JEO would address key components of the complete EJSM science objectives and would be designed to function alone or in conjunction with the ESA-led Jupiter Ganymede Orbiter and JAXA-led Jupiter Magnetospheric Orbiter. The JEO mission concept uses a single orbiter flight system which would travel to Jupiter to perform a multi-year study of the Jupiter system and Europa, including 2.5-3 years of Jupiter system science and a comprehensive Europa orbit phase of upt ot a year. This abstract describes the design concept of this mission.

  15. Hot Jupiters: how rapidly are they evaporating?

    NASA Astrophysics Data System (ADS)

    Garcia Munoz, A.; McConnell, J. C.; Caldwell, J. J.

    2005-08-01

    The detection of an extended atmosphere on the exoplanet HD 209458 b containing H, C and O and reaching as far out as 3-4 planetary radii (Vidal-Madjar et al. 2004, Astrophys. J. 604, L69-L72 ) constitutes a unique case in the study of so-called hot Jupiters. At 0.045 AU from its host star, stellar EUV radiation supplies HD 209458 b with sufficient energy so as to heat up its upper atmosphere and, presumably, power its evaporation. The goal of this work is two-fold: estimate the evaporation rate from the atmosphere of hot Jupiters, of importance for the understanding of their evolution, and predict the composition of their thermosphere, giving support to future observations. For this purpose we have built an idealized one-dimensional hydrodynamic model of the thermosphere of hot Jupiters, of particular relevance for HD 209458 b. Concentrations of H-, C- and O-bearing constituents, as well as density, velocity and temperature of the whole plasma, are solved self-consistently. The evaporation rate is fluid-dynamically constrained by the occurrence of a sonic point in the expansion of the atmospheric gas. Rapid adiabatic cooling may place an additional constraint on the thermal structure near the transition between the lower and upper atmospheres of these planets. Evaporation rates and profiles of constituents will be given for various planet-star distances, appropriate to very hot Jupiters ( ˜ 0.02 AU), hot Jupiters ( ˜ 0.05 AU) and more temperate conditions (> 0.1 AU).

  16. Light-Curve Survey of Jupiter Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Melita, M.; Ortiz, J. L.; Licandro, J.; Williams, I. P.; Jones, D.

    2008-09-01

    Trojan asteroids are an interesting population of minor bodies due to their dynamical characteristics, their physical properties and that they are relatively isolated located at the snow-line The main hypotheses about the origin of the Jupiter Trojans assumed that they formed either during the final stages of the planetary formation (Marzari & Scholl 1998), or during the epoch of planetary migration (Morbidelli et al. 2005), in any case more than 3.8 Gy. ago. The dynamical configuration kept the Trojans isolated from the asteroid Main Belt throughout the history of the Solar System. In spite of eventual interactions with other populations of minor bodies like the Hildas, the Jupiter family comets, and the Centaurs, their collisional evolution has been dictated mostly by the intrapopulation collisions (Marzari et al. 1996, 1997). Therefore, the Jupiter Trojans may be considered primordial bodies, whose dynamical and physical properties can provide important clues about the environment of planetary formation. The available sample of Jupiter Trojans light-curves is small and mainly restricted to the largest objects. According to the MPC-website (updated last in March 2006), the present sample of rotation periods and light-curve-amplitudes of the Jupiter Trojan asteroids is composed by 25 objects with some information about their periods and by 10 of them with only an amplitude estimation. A survey of contact binary Trojan asteroids has been done by Mann et al. 2007, where they have recorded more than 100 amplitudes from sparse-sampled light-curves and very-wellresolved rotational periods. More than 2000 Trojan asteroids have been discovered up to date, so, there is an urgent need to enlarge the sample of intrinsic rotation periods and accurate light-curve amplitudes and to extend it to smaller sizes. Results and Discusions We requested 26 nights of observation in the second semester of 2007, to begin with the survey. They were scheduled for the following instruments

  17. VAN method lacks validity

    NASA Astrophysics Data System (ADS)

    Jackson, David D.; Kagan, Yan Y.

    Varotsos and colleagues (the VAN group) claim to have successfully predicted many earthquakes in Greece. Several authors have refuted these claims, as reported in the May 27,1996, special issue of Geophysical Research Letters and a recent book, A Critical Review of VAN [Lighthill 1996]. Nevertheless, the myth persists. Here we summarize why the VAN group's claims lack validity.The VAN group observes electrical potential differences that they call “seismic electric signals” (SES) weeks before and hundreds of kilometers away from some earthquakes, claiming that SES are somehow premonitory. This would require that increases in stress or decreases in strength cause the electrical variations, or that some regional process first causes the electrical signals and then helps trigger the earthquakes. Here we adopt their notation SES to refer to the electrical variations, without accepting any link to the quakes.

  18. Kepler-424 b: A 'lonely' hot Jupiter that found A companion

    SciTech Connect

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Havel, Mathieu; Howell, Steve B.; Quintana, Elisa; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Lucas, Phillip; Fischer, Debra; Ciardi, David R.

    2014-11-10

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be {sup l}onely{sup .} This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to υ Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M {sub ⊕}.

  19. Kepler-424 b: A "Lonely" Hot Jupiter that Found a Companion

    NASA Astrophysics Data System (ADS)

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Havel, Mathieu; Lucas, Phillip; Howell, Steve B.; Fischer, Debra; Quintana, Elisa; Ciardi, David R.

    2014-11-01

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be "lonely". This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to \\upsilon Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M ⊕. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  20. Three spacecraft observe Jupiter's glowing polar regions

    NASA Astrophysics Data System (ADS)

    1996-09-01

    The aurorae on Jupiter are like the Aurorae Borealis and Australis on the Earth, although visible only by ultraviolet light. They flicker in a similar way in response to variations in the solar wind of charged particles blowing from the Sun. While Galileo monitored the changing environment of particles and magnetism in Jupiter's vicinity, IUE recorded surprisingly large and rapid variations in the overall strength of the auroral activity. IUE's main 45-centimetre telescope did not supply images,but broke up the ultraviolet rays into spectra, like invisible rainbows, from which astrophysicists could deduce chemical compositions, motions and temperatures in the cosmic objects under examination. In the case of Jupiter's aurorae, the strongest emission came from activated hydrogen atoms at a wavelength of 1216 angstroms. The Hubble Space Telescope's contributions to the International Jupiter Watch included images showing variations in the form of the aurorae, and "close-up" spectra of parts of the auroral ovals. Astronomers will compare the flickering aurorae on Jupiter with concurrent monitoring of the Sun and the solar wind by the ESA-NASA SOHO spacecraft and several satellites of the Interagency Solar-Terrestrial Programme. It is notable that changes in auroral intensity by a factor of two or three occurred during the 1996 observational period, even though the Sun was in an exceptionally quiet phase, with very few sunspots. In principle, a watch on Jupiter's aurorae could become a valuable means of checking the long-range effects of solar activity, which also has important consequences for the Earth. The situation at Jupiter is quite different from the Earth's, with the moons strongly influencing the planet's space environment. But with Hubble busy with other work, any such Jupiter-monitoring programme will have to await a new ultraviolet space observatory. IUE observed Jupiter intensively in 1979-80 in conjunction with the visits of NASA's Voyager spacecraft, and

  1. Final Masses of Giant Planets II: Jupiter Formation in a Gas-Depleted Disk

    NASA Astrophysics Data System (ADS)

    Tanigawa, Takayuki; Tanaka, Hidekazu

    2015-12-01

    Firstly, we study the final masses of giant planets growing in protoplanetary disks through capture of disk gas, by employing an empirical formula for the gas capture rate and a shallow disk gap model, which are both based on hydrodynamical simulations. The shallow disk gaps cannot terminate growth of giant planets. For planets less massive than 10 Jupiter masses, their growth rates are mainly controlled by the gas supply through the global disk accretion, rather than their gaps. The insufficient gas supply compared with the rapid gas capture causes a depletion of the gas surface density even at the outside of the gap, which can create an inner hole in the protoplanetary disk. Our model can also predict how deep the inner hole is for a given planet mass. Secondly, our findings are applied to the formation of our solar system. For the formation of Jupiter, a very low-mass gas disk with a few or several Jupiter masses is required at the beginning of its gas capture because of the non-stopping capture. Such a low-mass gas disk with sufficient solid material can be formed through viscous evolution from an initially ˜10AU-sized compact disk with the solar composition. By the viscous evolution with a moderate viscosity of α˜10-3, most of disk gas accretes onto the sun and a widely spread low-mass gas disk remains when the solid core of Jupiter starts gas capture at t˜107 yrs. The depletion of the disk gas is suitable for explaining the high metallicity in giant planets of our solar system. A very low-mass gas disk also provides a plausible path where type I and II planetary migrations are both suppressed significantly. In particular, we also show that the type II migration of Jupiter-size planets becomes inefficient because of the additional gas depletion due to the rapid gas capture by themselves.

  2. LOFAR's Potential to Characterize Jupiter's Radiation Environment

    NASA Astrophysics Data System (ADS)

    de Pater, I.

    2008-09-01

    Jupiter is a strong source of radio emissions, as discovered in the early 1950s (Burke and Franklin, 1955). These first detections revealed emissions that were sporadic in character, and confined to frequencies less than 40 MHz. This component of the planet's radio emission is commonly referred to as decametric (DAM) radiation, and is attributed to electron cyclotron maser emission, emitted by keV electrons in Jupiter's auroral regions. All four giant planets and the Earth emit such radiation. To date these emissions have been studied in the timefrequency domain, since it has not been possible to image at these low frequencies. A new Low Frequency Array, LOFAR, is momentarily being build in the Netherlands. It consists of a low (~30-80 MHz) and high (~120-240 MHz) frequency band, with baselines between 100 m up to 100 km. By connecting (VLBI) with the Nancay radio telescope, baselines of 700 km can be achieved. This telescope complements the VLA (Very large Array) and ATA (Allen Telescope Array) in frequency coverage, and using the combined arrays (quasi)- simultaneously, Jupiter's radiation environment can be mapped from about 20 MHz (the low LOFAR band is still sensitive below 30 MHz, but with reduced through-put) up to 20 GHz. Jupiter emits both synchrotron and coherent cyclotron radiation at low frequencies (e.g., de Pater 2004; Zarka, 2004). Synchrotron radiation is emitted by relativistic electrons (MeV) trapped in Jupiter's radiation belts; this component of the emission has been imaged regularly at higher (> 300 MHz) frequencies. Simultaneous high resolution imaging at low frequencies will help identify the origin and mode of transport of the synchrotron radiating electrons, including their source and loss terms. At frequencies below 40 MHz LOFAR could, for the first time ever, image Jupiter's decametric (DAM) emissions. These emissions have been observed since the early 1950's, and are characterized by complex, highly organized structures in the frequency

  3. Spatial distribution of water in the stratosphere of Jupiter from Herschel HIFI and PACS observations

    NASA Astrophysics Data System (ADS)

    Cavalié, T.; Feuchtgruber, H.; Lellouch, E.; de Val-Borro, M.; Jarchow, C.; Moreno, R.; Hartogh, P.; Orton, G.; Greathouse, T. K.; Billebaud, F.; Dobrijevic, M.; Lara, L. M.; González, A.; Sagawa, H.

    2013-05-01

    Context. In the past 15 years, several studies suggested that water in the stratosphere of Jupiter originated from the Shoemaker-Levy 9 (SL9) comet impacts in July 1994, but a direct proof was missing. Only a very sensitive instrument observing with high spectral/spatial resolution can help to solve this problem. This is the case of the Herschel Space Observatory, which is the first telescope capable of mapping water in Jupiter's stratosphere. Aims: We observed the spatial distribution of the water emission in Jupiter's stratosphere with the Heterodyne Instrument for the Far Infrared (HIFI) and the Photodetector Array Camera and Spectrometer (PACS) onboard Herschel to constrain its origin. In parallel, we monitored Jupiter's stratospheric temperature with the NASA Infrared Telescope Facility (IRTF) to separate temperature from water variability. Methods: We obtained a 25-point map of the 1669.9 GHz water line with HIFI in July 2010 and several maps with PACS in October 2009 and December 2010. The 2010 PACS map is a 400-point raster of the water 66.4 μm emission. Additionally, we mapped the methane ν4 band emission to constrain the stratospheric temperature in Jupiter in the same periods with the IRTF. Results: Water is found to be restricted to pressures lower than 2 mbar. Its column density decreases by a factor of 2-3 between southern and northern latitudes, consistently between the HIFI and the PACS 66.4 μm maps. We infer that an emission maximum seen around 15 °S is caused by a warm stratospheric belt detected in the IRTF data. Conclusions: Latitudinal temperature variability cannot explain the global north-south asymmetry in the water maps. From the latitudinal and vertical distributions of water in Jupiter's stratosphere, we rule out interplanetary dust particles as its main source. Furthermore, we demonstrate that Jupiter's stratospheric water was delivered by the SL9 comet and that more than 95% of the observed water comes from the comet according to

  4. Effect of the Solar UV/EUV Heating on the Intensity and Spatial Distribution of Jupiter's Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Kita, Hajime; Misawa, H.; Tsuchiya, F.; Tao, C.; Morioka, A.

    2012-10-01

    Jupiter's synchrotron radiation (JSR) is the emission from relativistic electrons, and it is the most effective probe for remote sensing of Jupiter's radiation belt from the Earth. Recent observations reveal short term variations of JSR with the time scale of days to weeks. Brice and McDonough (1973) proposed that the solar UV/EUV heating for Jupiter's upper atmosphere causes enhancement of total flux density. If such a process occurs at Jupiter, it is also expected that diurnal wind system produces dawn-dusk asymmetry of the JSR brightness distribution. Preceding studies confirmed that the short term variations in total flux density correspond to the solar UV/EUV. However, the effect of solar UV/EUV heating on the brightness distribution has not been confirmed. Hence, the purpose of this study is to confirm the solar UV/EUV heating effect on total flux density and brightness distribution. We made radio imaging analysis using the National Radio Astronomy Observatory (NRAO) archived data of the Very Large Array (VLA) obtained in 2000, and following results were shown. 1, Total flux density varied corresponding to the solar UV/EUV. 2, Dawn side emission was brighter than dusk side emission almost every day. 3, Variations of the dawn-dusk asymmetry did not correspond to the solar UV/EUV. In order to explain the second result, we estimate the diurnal wind velocity from the observed dawn-dusk ratio by using the model brightness distribution of JSR. Estimated neutral wind velocity is 46+/-11 m/s, which reasonably corresponds to the numerical simulation of Jupiter's upper atmosphere. In order to explain the third result, we examined the effect of the global convection electric field driven by tailward outflow of plasma in Jupiter's magnetosphere. As the result, it is suggested that typical fluctuation of the convection electric field strength was enough to cause the observed variations of the dawn-dusk asymmetry.

  5. Understanding of Jupiter's Atmosphere after the Galileo Probe Entry

    NASA Technical Reports Server (NTRS)

    Fonda, Mark (Technical Monitor); Young, Richard E.

    2003-01-01

    Instruments on the Galileo probe measured composition, cloud properties, thermal structure, winds, radiative energy balance, and electrical properties of the Jovian atmosphere. As expected the probe results confirm some expectations about Jupiter's atmosphere, refute others, and raise new questions which still remain unanswered. This talk will concentrate on those aspects of the probe observations which either raised new questions or remain unresolved. The Galileo probe observations of composition and clouds provided some of the biggest surprises of the mission. Helium abundance measured by the probe differed significantly from the remote sensing derivations from Voyager. Discrepancy between the Voyager helium abundance determinations for Jupiter and the Galileo probe value have now led to a considerably increased helium determination for Saturn. Global abundance of N in the form of ammonia was observed to be super-solar by approximately the same factor as carbon, in contrast to expectations that C/N would be significantly larger than solar. This has implications for the formation and evolution of Jupiter. The cloud structure was not what was generally anticipated, even though most previous remote sensing results below the uppermost cloud referred to 5 micron hot spots, local regions with reduced cloud opacity. The Galileo probe descended in one of these hot spots. Only a tenuous, presumed ammomium hydrosulfide, cloud was detected, and no significant water cloud or super-solar water abundance was measured. The mixing ratios as a function of depth for the condensibles ammonia, hydrogen sulfide, and water, exhibited no apparent correlation with either condensation levels or with each other, an observation that is still a puzzle, although there are now dynamical models of hot spots which show promise in being able to explain such behavior. Probe tracked zonal winds show that wind magnitude increases with depth to pressures of about 4 bars, with the winds extending to

  6. Understanding of Jupiter's Atmosphere After the Galileo Probe Entry

    NASA Technical Reports Server (NTRS)

    Young, Richard E.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Instruments on the Galileo probe measured composition, cloud properties, thermal structure. winds, radiative energy balance, and electrical properties of the Jovian atmosphere. As expected the probe results confirm some expectations about Jupiter's atmosphere, refute others, and raise new questions which still remain unanswered. This talk will concentrate on those aspects of the probe observations which either raised new questions or remain unresolved. The Galileo probe observations of composition and clouds provided some of the biggest surprises of the mission. Helium abundance measured by the probe differed significantly from the remote sensing derivations from Voyager. discrepancy between the Voyager helium abundance determinations for Jupiter and the Galileo probe value have now led to a considerably increased helium determination for Saturn. Global abundance of N in the form of ammonia was observed to be supersolar by approximately the same factor as carbon, in contrast to expectations that C/N would be significantly larger than solar. This has implications for the formation and evolution of Jupiter. The cloud structure was not what was generally anticipated, even though most previous remote sensing results below the uppermost cloud referred to 5 micron hot spots, local regions with reduced cloud opacity. The Galileo probe descended in one of these hot spots. Only a tenuous, presumed ammonium hydrosulfide, cloud was detected, and no significant water cloud or super-solar water abundance was measured. The mixing ratios as a function of depth for the condensibles ammonia, hydrogen sulfide, and water, exhibited no apparent correlation with either condensation levels or with each other, an observation that is still a puzzle, although there are now dynamical models of hot spots which show promise in being able to explain such behavior. Probe tracked zonal winds show that wind magnitude increases with depth to pressures of about 4 bars, with the winds extending to

  7. Still from High-Clouds Jupiter Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image is one of seven from the narrow-angle camera on NASA's Cassini spacecraft assembled as a brief movie of high-altitude cloud movements on Jupiter. It was taken in early October 2000.

    The images were taken at a wavelength that is absorbed by methane, one chemical in Jupiter's lower clouds. So, dark areas are relatively free of high clouds, and the camera sees through to the methane in a lower level. Bright areas are places with high, thick clouds that shield the methane below.

    The area shown covers latitudes from 50 degrees north to 50 degrees south and a 100-degree sweep of longitude.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  8. Mission design of a Pioneer Jupiter Orbiter

    NASA Technical Reports Server (NTRS)

    Friedman, L. D.; Nunamaker, R. R.

    1975-01-01

    The Mission analysis and design work performed in order to define a Pioneer mission to orbit Jupiter is described. This work arose from the interaction with a science advisory 'Mission Definition' team and led to the present mission concept. Building on the previous Jupiter Orbiter-Satellite Tour development at JPL a magnetospheric survey mission concept is developed. The geometric control of orbits which then provide extensive local time coverage of the Jovian system is analyzed and merged with the various science and program objectives. The result is a 'flower-orbit' mission design, yielding three large apoapse excursions at various local times and many interior orbits whose shape and orientation is under continual modification. This orbit design, together with a first orbit defined by delivery of an atmospheric probe, yields a mission of high scientific interest.

  9. The atmospheres of Mars, Venus and Jupiter.

    PubMed

    Rasool, S I; Jastrow, R

    1964-01-01

    The general properties of the atmospheres of Mars, Venus and Jupiter are reviewed. The evolutionary processes of planetary atmospheres are outlined as an introduction to a detailed discussion of the structure of the atmospheres of other planets. The most recent observational results indicate that the surface pressure on Mars could be as low as 20 mb, and the amount of CO2 may have a mixing ratio as high as 25% by volume. For Venus, the Mariner II results suggest that the surface temperature may actually be of the order of 600 degrees K. Also there are indications that the surface pressure on Venus could be approximately 100 atm., with the atmosphere mainly composed of N2. In the case of Jupiter, recent theoretical investigations of the atmosphere below the clouds suggest, that there may be regions in the atmosphere of very high density and pressure but at relatively low temperature, creating conditions possibly favorable to the occurrence of complex organic reactions.

  10. MAGNETIC DRAG ON HOT JUPITER ATMOSPHERIC WINDS

    SciTech Connect

    Perna, Rosalba; Menou, Kristen; Rauscher, Emily

    2010-08-20

    Hot Jupiters, with atmospheric temperatures T {approx}> 1000 K, have residual thermal ionization levels sufficient for the interaction of ions with the planetary magnetic field to result in a sizable magnetic drag on the (neutral) atmospheric winds. We evaluate the magnitude of magnetic drag in a representative three-dimensional atmospheric model of the hot Jupiter HD 209458b and find that it is a plausible mechanism to limit wind speeds in this class of atmospheres. Magnetic drag has a strong geometrical dependence, both meridionally and from the dayside to the nightside (in the upper atmosphere), which could have interesting consequences for the atmospheric flow pattern. By extension, close-in eccentric planets with transiently heated atmospheres will experience time-variable levels of magnetic drag. A robust treatment of magnetic drag in circulation models for hot atmospheres may require iterated solutions to the magnetic induction and Saha equations as the hydrodynamic flow is evolved.

  11. Penetrative Convection and Zonal Flow on Jupiter

    PubMed

    Zhang; Schubert

    1996-08-16

    Measurements by the Galileo probe support the possibility that the zonal winds in Jupiter's atmosphere originate from convection that takes place in the deep hydrogen-helium interior. However, according to models based on recent opacity data and the probe's temperature measurements, there may be radiative and nonconvective layers in the outer part of the jovian interior, raising the question of how deep convection could extend to the surface. A theoretical model is presented to demonstrate that, because of predominant rotational effects and spherical geometry, thermal convection in the deep jovian interior can penetrate into any outer nonconvective layer. These penetrative convection rolls interact nonlinearly and efficiently in the model to generate and sustain a mean zonal wind with a larger amplitude than that of the nonaxisymmetric penetrative convective motions, a characteristic of the wind field observed at the cloud level on Jupiter. PMID:8688074

  12. Europa Planetary Protection for Juno Jupiter Orbiter

    NASA Technical Reports Server (NTRS)

    Bernard, Douglas E.; Abelson, Robert D.; Johannesen, Jennie R.; Lam, Try; McAlpine, William J.; Newlin, Laura E.

    2010-01-01

    NASA's Juno mission launched in 2011 and will explore the Jupiter system starting in 2016. Juno's suite of instruments is designed to investigate the atmosphere, gravitational fields, magnetic fields, and auroral regions. Its low perijove polar orbit will allow it to explore portions of the Jovian environment never before visited. While the Juno mission is not orbiting or flying close to Europa or the other Galilean satellites, planetary protection requirements for avoiding the contamination of Europa have been taken into account in the Juno mission design.The science mission is designed to conclude with a deorbit burn that disposes of the spacecraft in Jupiter's atmosphere. Compliance with planetary protection requirements is verified through a set of analyses including analysis of initial bioburden, analysis of the effect of bioburden reduction due to the space and Jovian radiation environments, probabilistic risk assessment of successful deorbit, Monte-Carlo orbit propagation, and bioburden reduction in the event of impact with an icy body.

  13. Launch of Jupiter-C/Explorer 1

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Launch of Jupiter-C/Explorer 1 at Cape Canaveral, Florida on January 31, 1958. After the Russian Sputnik 1 was launched in October 1957, the launching of an American satellite assumed much greater importance. After the Vanguard rocket exploded on the pad in December 1957, the ability to orbit a satellite became a matter of national prestige. On January 31, 1958, slightly more than four weeks after the launch of Sputnik.The ABMA (Army Ballistic Missile Agency) in Redstone Arsenal, Huntsville, Alabama, in cooperation with the Jet Propulsion Laboratory, launched a Jupiter from Cape Canaveral, Florida. The rocket consisted of a modified version of the Redstone rocket's first stage and two upper stages of clustered Baby Sergeant rockets developed by the Jet Propulsion Laboratory and later designated as Juno boosters for space launches

  14. Launch, Jupiter-C, Explorer 1

    NASA Technical Reports Server (NTRS)

    1958-01-01

    Launch of Jupiter-C/Explorer 1 at Cape Canaveral, Florida on January 31, 1958. After the Russian Sputnik 1 was launched in October 1957, the launching of an American satellite assumed much greater importance. After the Vanguard rocket exploded on the pad in December 1957, the ability to orbit a satellite became a matter of national prestige. On January 31, 1958, slightly more than four weeks after the launch of Sputnik.The ABMA (Army Ballistic Missile Agency) in Redstone Arsenal, Huntsville, Alabama, in cooperation with the Jet Propulsion Laboratory, launched a Jupiter from Cape Canaveral, Florida. The rocket consisted of a modified version of the Redstone rocket's first stage and two upper stages of clustered Baby Sergeant rockets developed by the Jet Propulsion Laboratory and later designated as Juno boosters for space launches

  15. Searching for Global oscillations of Jupiter

    NASA Astrophysics Data System (ADS)

    Murphy, N.; Smith, E. J.; Rogers, W.; Gillam, S.; Rosner, R.; Baliunas, S.

    2000-12-01

    The detection of global oscillations of Jupiter would lead to significant advances in our understanding of giant planet internal structure, analogous to the enormous increase in knowledge of the sun's interior facilitated by helioseismology. In particular, the frequencies of p-mode oscillations will be strongly affected by the presence of density discontinuities and the planet's core size and structure. While it is clear from previous observations that such oscillations probably only exist with very small amplitudes, current instrumentation may still be able to detect them. We will describe a proposed experiment to detect (or place a firm upper amplitude limit on) global p-mode oscillations of Jupiter, using a magneto-optical filter on the Mt Wilson 100" telescope. We will describe the operation of the instrument, present preliminary data and describe models of instrument response which show that with 7 nights of data we can expect to detect signals with amplitudes less than 20 cm/s.

  16. The Dusk Flank of Jupiter's Magnetosphere

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.; Gurnett, D. A.; Hospodarsky, G. B.; Farrell, W. M.; Roux, A.; Dougherty, M. K.; Joy, S. P.; Kivelson, M. G.; Walker, R. J.; Crary, F. J.

    2002-01-01

    Limited single-spacecraft observations of Jupiter's magnetopause have been used to infer that the boundary moves inward or outward in response to variations in the dynamic pressure of the solar wind. At Earth, multiple-spacecraft observations have been implemented to understand the physics of how this motion occurs, because they can provide a snapshot of a transient event in progress. Here we present a set of nearly simultaneous two-point measurements of the jovian magnetopause at a time when the jovian magnetopause was in a state of transition from a relatively larger to a relatively smaller size in response to an increase in solar-wind pressure. The response of Jupiter's magnetopause is very similar to that of the Earth, confirming that the understanding built on studies of the Earth's magnetosphere is valid. The data also reveal evidence for a well-developed boundary layer just inside the magnetopause.

  17. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view from the southwest looking northeast, from an altitude just above the high haze layer. The streaks in the lower cloud leading towards the hotspot are visible. The upper haze layer is mostly flat, with notable small peaks that can be matched with features in the lower cloud. In reality, these areas may represent a continuous vertical cloud column.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756

  18. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the northeast, from between the cloud layers and above the streaks in the lower cloud leading towards the hotspot. The upper haze layer has some features that match the lower cloud, such as the bright streak in the foreground of the frame. These are probably thick clouds that span several tens of vertical kilometers.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756 nm. This model is overly

  19. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view from above and to the south of the visualized area, showing the entire model. The entire region is overlain by a thin, transparent haze. In places the haze is high and thick, especially to the east (to the right of) the hotspot.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756 nm. This model is overly simplistic, but is based on more sophisticated studies of Jupiter's cloud structure. The upper

  20. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the northeast, from between the cloud layers and above the streaks in the lower cloud leading towards the hotspot. The hotspot is clearly visible as a deep blue feature. The cloud streaks end near the hotspot, consistent with the idea that clouds traveling along these streak lines descend and evaporate as they approach the hotspot. The upper haze layer is slightly bowed upwards above the hotspot.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional

  1. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the southeast, from between the cloud layers and over the north center of the region. The tall white clouds in the lower cloud deck are probably much like large terrestrial thunderclouds. They may be regions where atmospheric water powers vertical convection over large horizontal distances.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756 nm. This model is overly simplistic, but is based on

  2. Three dimensional Visualization of Jupiter's Equatorial Region

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frames from a three dimensional visualization of Jupiter's equatorial region. The images used cover an area of 34,000 kilometers by 11,000 kilometers (about 21,100 by 6,800 miles) near an equatorial 'hotspot' similar to the site where the probe from NASA's Galileo spacecraft entered Jupiter's atmosphere on December 7th, 1995. These features are holes in the bright, reflective, equatorial cloud layer where warmer thermal emission from Jupiter's deep atmosphere can pass through. The circulation patterns observed here along with the composition measurements from the Galileo Probe suggest that dry air may be converging and sinking over these regions, maintaining their cloud-free appearance. The bright clouds to the right of the hotspot as well as the other bright features may be examples of upwelling of moist air and condensation.

    This frame is a view to the west, from between the cloud layers and over the patchy white clouds to the east of the hotspot. This is probably an area where moist convection is occurring over large horizontal distances, similar to the atmosphere over the equatorial ocean on Earth. The clouds are high and thick, and are observed to change rapidly over short time scales.

    Galileo is the first spacecraft to image Jupiter in near-infrared light (which is invisible to the human eye) using three filters at 727, 756, and 889 nanometers (nm). Because light at these three wavelengths is absorbed at different altitudes by atmospheric methane, a comparison of the resulting images reveals information about the heights of clouds in Jupiter's atmosphere. This information can be visualized by rendering cloud surfaces with the appropriate height variations.

    The visualization reduces Jupiter's true cloud structure to two layers. The height of a high haze layer is assumed to be proportional to the reflectivity of Jupiter at 889 nm. The height of a lower tropospheric cloud is assumed to be proportional to the reflectivity at 727 nm divided by that at 756

  3. The dusk flank of Jupiter's magnetosphere.

    PubMed

    Kurth, W S; Gurnett, D A; Hospodarsky, G B; Farrell, W M; Roux, A; Dougherty, M K; Joy, S P; Kivelson, M G; Walker, R J; Crary, F J; Alexander, C J

    2002-02-28

    Limited single-spacecraft observations of Jupiter's magnetopause have been used to infer that the boundary moves inward or outward in response to variations in the dynamic pressure of the solar wind. At Earth, multiple-spacecraft observations have been implemented to understand the physics of how this motion occurs, because they can provide a snapshot of a transient event in progress. Here we present a set of nearly simultaneous two-point measurements of the jovian magnetopause at a time when the jovian magnetopause was in a state of transition from a relatively larger to a relatively smaller size in response to an increase in solar-wind pressure. The response of Jupiter's magnetopause is very similar to that of the Earth, confirming that the understanding built on studies of the Earth's magnetosphere is valid. The data also reveal evidence for a well-developed boundary layer just inside the magnetopause.

  4. The dusk flank of Jupiter's magnetosphere.

    PubMed

    Kurth, W S; Gurnett, D A; Hospodarsky, G B; Farrell, W M; Roux, A; Dougherty, M K; Joy, S P; Kivelson, M G; Walker, R J; Crary, F J; Alexander, C J

    2002-02-28

    Limited single-spacecraft observations of Jupiter's magnetopause have been used to infer that the boundary moves inward or outward in response to variations in the dynamic pressure of the solar wind. At Earth, multiple-spacecraft observations have been implemented to understand the physics of how this motion occurs, because they can provide a snapshot of a transient event in progress. Here we present a set of nearly simultaneous two-point measurements of the jovian magnetopause at a time when the jovian magnetopause was in a state of transition from a relatively larger to a relatively smaller size in response to an increase in solar-wind pressure. The response of Jupiter's magnetopause is very similar to that of the Earth, confirming that the understanding built on studies of the Earth's magnetosphere is valid. The data also reveal evidence for a well-developed boundary layer just inside the magnetopause. PMID:11875558

  5. Thermal Emission from Transiting Very Hot Jupiters: Prospects for Ground-based Detection at Optical Wavelengths

    NASA Astrophysics Data System (ADS)

    López-Morales, Mercedes; Seager, Sara

    2007-10-01

    Very hot Jupiters (VHJs) are defined as Jupiter-mass extrasolar planets with orbital periods shorter than 3 days. For low albedos the effective temperatures of irradiated VHJs can reach 2500-3000 K. Thermal emission from VHJs is therefore potentially strong at optical wavelengths. We explore the prospects of detecting optical-wavelength thermal emission during secondary eclipse with existing ground-based telescopes. We show that OGLE-TR-56b and OGLE-TR-132b are the best-suited candidates for detection and that the prospects are highest around z' band (~0.9 μm). We also speculate that any newly discovered VHJs with the right combination of orbital separation and host star parameters could be thermally detected in the optical. The lack of detections would still provide constraints on the planetary albedos and reradiation factors.

  6. Photometric observations of Jupiter at 2400 angstroms

    NASA Technical Reports Server (NTRS)

    Hord, C. W.; West, R. A.; Simmons, K. E.; Coffeen, D. L.; Sato, M.; Lane, A. L.; Bergstralh, J. T.

    1979-01-01

    The photopolarimeter instrument on Voyager 2 was used to obtain a map of Jupiter at an effective wavelength of 2400 angstroms. Analysis of a typical north-south swath used to make this map shows strong absorption at high latitudes by a molecular or particulate constituent in the Jovian atmosphere. At 65 deg north latitude, the absorbing constituent extends to altitudes above the 50-millibar pressure level

  7. EQUATORIAL ZONAL JETS AND JUPITER's GRAVITY

    SciTech Connect

    Kong, D.; Liao, X.; Zhang, K.; Schubert, G.

    2014-08-20

    The depth of penetration of Jupiter's zonal winds into the planet's interior is unknown. A possible way to determine the depth is to measure the effects of the winds on the planet's high-order zonal gravitational coefficients, a task to be undertaken by the Juno spacecraft. It is shown here that the equatorial winds alone largely determine these coefficients which are nearly independent of the depth of the non-equatorial winds.

  8. The time variability of Jupiter's synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Bolton, Scott Jay

    1991-02-01

    The time variability of the Jovian synchrotron emission is investigated by analyzing radio observations of Jupiter at decimetric wavelengths. The observations are composed from two distinct sets of measurements addressing both short term (days to weeks) and long term (months to years) variability. The study of long term variations utilizes a set of measurements made several times each month with the NASA Deep Space Network (DNS) antennas operating at 2295 MHz (13.1 cm). The DSN data set, covering 1971 through 1985, is compared with a set of measurements of the solar wind from a number of Earth orbiting spacecraft. The analysis indicates a maximum correlation between the synchrotron emission and the solar wind ram pressure with a two year time lag. Physical mechanisms affecting the synchrotron emission are discussed with an emphasis on radial diffusion. Calculations are performed that suggest the correlation is consistent with inward adiabatic diffusion of solar wind particles driven by Brice's model of ionospheric neutral wind convection (Brice 1972). The implication is that the solar wind could be a source of particles of Jupiter's radiation belts. The investigation of short term variability focuses on a three year Jupiter observing program using the University of California's Hat Creek radio telescope operating at 1400 MHz (21 cm). Measurements are made every two days during the months surrounding opposition. Results from the three year program suggest short term variability near the 10-20 percent level but should be considered inconclusive due to scheduling and observational limitations. A discussion of magneto-spheric processes on short term timescales identifies wave-particle interactions as a candidate source. Further analysis finds that the short term variations could be related to whistler mode wave-particles interactions in the radiation belts associated with atmospheric lightning on Jupiter. However, theoretical calculations on wave particle interactions

  9. DIRECTLY IMAGING TIDALLY POWERED MIGRATING JUPITERS

    SciTech Connect

    Dong Subo; Katz, Boaz; Socrates, Aristotle

    2013-01-10

    Upcoming direct-imaging experiments may detect a new class of long-period, highly luminous, tidally powered extrasolar gas giants. Even though they are hosted by {approx} Gyr-'old' main-sequence stars, they can be as 'hot' as young Jupiters at {approx}100 Myr, the prime targets of direct-imaging surveys. They are on years-long orbits and presently migrating to 'feed' the 'hot Jupiters'. They are expected from 'high-e' migration mechanisms, in which Jupiters are excited to highly eccentric orbits and then shrink semimajor axis by a factor of {approx}10-100 due to tidal dissipation at close periastron passages. The dissipated orbital energy is converted to heat, and if it is deposited deep enough into the atmosphere, the planet likely radiates steadily at luminosity L {approx} 100-1000 L{sub Jup}(2 Multiplication-Sign 10{sup -7}-2 Multiplication-Sign 10{sup -6} L{sub Sun }) during a typical {approx} Gyr migration timescale. Their large orbital separations and expected high planet-to-star flux ratios in IR make them potentially accessible to high-contrast imaging instruments on 10 m class telescopes. {approx}10 such planets are expected to exist around FGK dwarfs within {approx}50 pc. Long-period radial velocity planets are viable candidates, and the highly eccentric planet HD 20782b at maximum angular separation {approx}0.''08 is a promising candidate. Directly imaging these tidally powered Jupiters would enable a direct test of high-e migration mechanisms. Once detected, the luminosity would provide a direct measurement of the migration rate, and together with mass (and possibly radius) estimate, they would serve as a laboratory to study planetary spectral formation and tidal physics.

  10. Europa's Interaction with the Magnetosphere of Jupiter

    NASA Astrophysics Data System (ADS)

    Khurana, Krishan K.; Jia, Xianzhe; Paranicas, Chris; Cassidy, Timothy A.; Hansen, Kenneth C.

    2013-04-01

    Galileo's observations of magnetic field in the vicinity of Europa have shown that Europa does not possess an appreciable internal magnetic field. However, Europa strongly modifies its plasma and magnetic field environment by directly interacting with the magnetosphere of Jupiter. The plasma interactions cause the absorption of Jovian plasma by the moon, pick-up of newly formed ions from the exospheres of the moon, plasma diversion by electrodynamic (Alfvén wing) interaction and the formation of a long wake in the downstream region. In addition to the electrodynamic interactions, Europa also displays electromagnetic induction response to the rotating field of Jupiter presumably from the conducting presence of global salty liquid oceans inside the moon. Galileo successfully encountered Europa 10 times during its mission. We are developing quantitative 3-D MHD models of plasma interactions of Europa with Jupiter's magnetosphere. In these models we include the effects of plasma pick-up and plasma interaction with a realistic exosphere as well as the contribution of the electromagnetic induction. We will present results of these quantitative models and show that the plasma interaction is strongest when Europa is located at the center of Jupiter's current sheet. We find that plasma mass loading rates are extremely variable over time. We will investigate various mechanisms by which such variability in mass-loading could be produced including episodically enhanced sputtering from trapped gaseous molecules in ice and enhanced plasma interaction with a vent(s) generated dense exosphere. The new model will aid researchers in planning observations from future missions such as JUICE and Europa flagship mission.

  11. Mariner Jupiter/Saturn infrared instrument study

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Mariner Jupiter/Saturn infrared instrumentation conceptual design study was conducted to determine the physical and operational characteristics of the instruments needed to satisfy the experiment science requirements. The design of the instruments is based on using as many proven concepts as possible. Many design features are taken from current developments such as the Mariner, Pioneer 10, Viking Orbiter radiometers, and Nimbus D spectrometer. Calibration techniques and error analysis for the instrument system are discussed.

  12. The Jupiter Icy Moons Orbiter reference trajectory

    NASA Technical Reports Server (NTRS)

    Whiffen, Gregory J.; Lam, Try

    2006-01-01

    The proposed NASA Jupiter Icy Moons Orbiter (JIMO) mission would have used a single spacecraft to orbit Callisto, Ganymede, and Europa in succession. The enormous Delta-Velocity required for this mission (nearly [25 km/s]) would necessitate the use of very high efficiency electric propulsion. The trajectory created for the proposed baseline JIMO mission may be the most complex trajectory ever designed. This paper describes the current reference trajectory in detail and describes the processes that were used to construct it.

  13. Monitoring Jupiter's Atmosphere for Tidal Oscillations

    NASA Astrophysics Data System (ADS)

    Houben, H.; Mosqueira, I.; Showman, A.; Young, R. E.

    2003-12-01

    Tidal dissipation in Jupiter is the ultimate source of the energy that powers Io's volcanism and may also be an important cause of heating in Europa and Ganymede. However, the mechanism of jovian tidal dissipation is still unknown. In general, there are two possibilities that can work in a fluid planet: 1) some viscous process in the interior of the planet (although eddy viscosity due to convective overturning can be excluded because of the large mismatch between the tidal period and the convective eddy timescale); or 2) the generation of inertia-gravity waves (a natural consequence of tidal forcing in any stably stratified fluid) that propagate to the upper atmosphere before breaking. Our calculations rule out the possibility that a stable, resonant, ducting layer in the atmosphere or outer envelope of Jupiter would result in large wave amplitudes and dissipate enough energy to account for a longterm average tidal dissipation factor (Q) of 105. But, we cannot exclude the possibility that a stable layer (perhaps due to composition gradients) in the deep interior would have this effect. The resulting energy flux ( ˜ 1021 erg/s) would be an important factor in the thermospheric heat balance. Thus, by monitoring Jupiter's atmosphere to determine the amplitude of the tidal wave response, JIMO would contribute to the understanding of the longterm orbital and thermal evolution of the Galilean satellites, while also shedding light on Jupiter's interior structure and upper atmospheric heat balance. Even a negative result would be valuable. Although global jovian atmospheric oscillations have been difficult to observe, the fact that we know the tidal frequencies and wavenumbers exactly will make it possible to add even random or opportunistic observations in phase to enhance the desired signal. We estimate that the waves will have a temperature amplitude less than 1 K, but a horizontal wind amplitude of up to 10 m/s at the 100 mbar level of the atmosphere.

  14. Jupiter's hydrogen bulge: A Cassini perspective

    NASA Astrophysics Data System (ADS)

    Melin, Henrik; Stallard, T. S.

    2016-11-01

    We present observations of H Ly-α and H2 emissions on the body of Jupiter obtained during the Cassini flyby in late 2000 and early 2001. The H Ly-α emission is highly organised by System III longitude and latitude, peaking at a brightness of 22 kR between 90 and 120° longitude. This is known as the H Ly-α 'bulge'. These observations add to a number of previous studies, showing that the feature is very long-lived, present over several decades. We show that there is a strong correlation between the prevailing solar H Ly-α flux (measured at Earth) and the peak brightness of the H Ly-α bulge at Jupiter, which supports the notion that it is primarily driven by solar resonance scatter. The H Ly-α brightness distribution is not aligned with the jovigraphic equator, but is approximately aligned with the particle drift equator of some, but not all, major Jupiter magnetic field models. On the time scale of days, the bulge region appears twice as variable as the non-bulge region. We propose that the electron recombination of H3+ is an important reaction for the generation of the H Ly-α bulge, which requires an enhancement of soft electrons at the location of the bulge. We derive an equatorial H3+ lifetime of 1.6 ± 0.4 h and a corresponding column averaged electron density of 1.7 × 109 m-3.

  15. New Horizons Imaging of Jupiter's Main Ring

    NASA Astrophysics Data System (ADS)

    Throop, Henry B.; Showalter, Mark Robert; Dones, Henry C. Luke; Hamilton, D. P.; Weaver, Harold A.; Cheng, Andrew F.; Stern, S. Alan; Young, Leslie; Olkin, Catherine B.; New Horizons Science Team

    2016-10-01

    New Horizons took roughly 520 visible-light images of Jupiter's ring system during its 2007 flyby, using the spacecraft's Long-Range Reconnaissance Imager (LORRI). These observations were taken over nine days surrounding Jupiter close-approach. They span a range in distance of 30 - 100 RJ, and a phase angle range of 20 - 174 degrees. The highest resolution images -- more than 200 frames -- were taken at a resolution approaching 20 km/pix.We will present an analysis of this dataset, much of which has not been studied in detail before. Our results include New Horizons' first quantitative measurements of the ring's intrinsic brightness and variability. We will also present results on the ring's azimuthal and radial structure. Our measurements of the ring's phase curve will be used to infer properties of the ring's dust grains.Our results build on the only previous analysis of the New Horizons Jupiter ring data set, presented in Showalter et al (2007, Science 318, 232-234), which detected ring clumps and placed a lower limit on the population of undetected ring-moons.This work was supported by NASA's OPR program.

  16. Hubble Gallery of Jupiter's Galilean Satellites

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This is a Hubble Space Telescope 'family portrait' of the four largest moons of Jupiter, first observed by the Italian scientist Galileo Galilei nearly four centuries ago. Located approximately one-half billion miles away, the moons are so small that, in visible light, they appear as fuzzy disks in the largest ground-based telescopes. Hubble can resolve surface details seen previously only by the Voyager spacecraft in the early 1980s. While the Voyagers provided close-up snapshots of the satellites, Hubble can now follow changes on the moons and reveal other characteristics at ultraviolet and near-infrared wavelengths.

    Over the past year Hubble has charted new volcanic activity on Io's active surface, found a faint oxygen atmosphere on the moon Europa, and identified ozone on the surface of Ganymede. Hubble ultraviolet observations of Callisto show the presence of fresh ice on the surface that may indicate impacts from micrometeorites and charged particles from Jupiter's magnetosphere.

    Hubble observations will play a complementary role when the Galileo spacecraft arrives at Jupiter in December of this year.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  17. Solar wind influence on Jupiter's aurora

    NASA Astrophysics Data System (ADS)

    Gyalay, Szilard; Vogt, Marissa F.; Withers, Paul; Bunce, Emma J.

    2016-10-01

    Jupiter's main auroral emission is driven by a system of corotation enforcement currents that arises to speed up outflowing Iogenic plasma and is not due to the magnetosphere-solar wind interaction like at Earth. The solar wind is generally expected to have only a small influence on Jupiter's magnetosphere and aurora compared to the influence of rotational stresses due to the planet's rapid rotation. However, there is considerable observational evidence that the solar wind does affect the magnetopause standoff distance, auroral radio emissions, and the position and brightness of the UV auroral emissions. Using the Michigan Solar Wind Model (mSWiM) to predict the solar wind conditions upstream of Jupiter we have identified intervals of high and low solar wind dynamic pressure in the Galileo dataset, and use this information to quantify how a magnetospheric compression affects the magnetospheric field configuration. We have developed separate spatial fits to the compressed and nominal magnetic field data, accounting for variations with radial distance and local time. These two fits can be used to update the flux equivalence mapping model of Vogt et al. (2011), which links auroral features to source regions in the middle and outer magnetosphere. The updated version accounts for changing solar wind conditions and provides a way to quantify the expected solar wind-induced variability in the ionospheric mapping of the main auroral emission, satellite footprints, and other auroral features. Our results are highly relevant to interpretation of the new auroral observations from the Juno mission.

  18. Development of Global Magnetosphere Models of Jupiter

    NASA Technical Reports Server (NTRS)

    Khurana, Krishan K.

    2004-01-01

    The objective of the proposal was to construct global magnetospheric models of Jupiter for the use of Jovian magnetospheric community. In the four years of the grant period we were able to achieve all of the stated science objectives. The work has resulted in: 1) A new structural model of Jovian current sheet; 2) Global thickness map of the current sheet; 3) Magnetic field models of the current sheet; 4) The global model of Jupiter's magnetospheric field including hinging and delay of the current sheet, sweepback of the magnetic field and the shielding field of the magnetopause. To accomplish our work, we assembled an exhaustive magnetic field data base from all of the spacecraft that have visited Jupiter (Pioneers 10 and 11, Voyagers 1 and 2, Ulysses and Galileo). The data were rotated into system III and JSM coordinates. We used the data at resolutions of 1 minute (for studies of the structure of the current sheet) and 10 minutes (for building the global model).

  19. A new magnetic pumping accelerator of charged particles in Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Mu, J.-L.

    1993-07-01

    This paper proposes an acceleration mechanism to explain the observations of energetic particles in the inner magnetosphere of Jupiter. In the inner magnetosphere particles are convected towards and away from the Io plasma torus by the centrifugally driven interchange mode or by the longitudinal asymmetry of the magnetosphere and the Io plasma torus. They experience a varying (space-dependent in Jupiter's frame of reference) magnetic field and are subject to pitch-angle scattering by wave-particle interactions. Thus, an e-fold magnetic pumping acceleration is expected in the system. The calculations show that the accelerator can generate up to one MeV energy particles in about 10-15 times the characteristic convection time.

  20. Jupiters radiation belts and their effects on spacecraft

    NASA Technical Reports Server (NTRS)

    Parker, R. H.; Divita, E. L.; Gigas, G.

    1974-01-01

    The effects of electron and proton radiation on spacecraft which will operate in the trapped radiation belts of the planet Jupiter are described, and the techniques and results of the testing and simulation used in the radiation effects program are discussed. Available data from the Pioneer 10 encounter of Jupiter are compared with pre-encounter models of the Jupiter radiation belts. The implications that the measured Jovian radiation belts have for future missions are considered.

  1. Aeronautics and Space Reports number 267: Comet impacts Jupiter

    NASA Astrophysics Data System (ADS)

    1994-06-01

    This video contains three different segments of computer generated simulations of the impact of comet Shoemaker-Levy 9 with Jupiter that will take place in July 1994. It includes interviews with Shoemaker and Levy, discussing pictures taken at Mt. Kalamar Observatory, the comets approach to Jupiter, fragment size, and the affects of the comets impact on Jupiter and its atmosphere. The impact will be viewed by the Galileo Spacecraft.

  2. JUICE: A European Mission to Jupiter and its Icy Moons

    NASA Astrophysics Data System (ADS)

    Witasse, O.; Altobelli, N.; Barabash, S.; Bruzzone, L.; Dougherty, M.; Erd, C.; Fletcher, L.; Gladstone, R.; Grasset, O.; Gurvits, L.; Hartogh, P.; Hussmann, H.; Iess, I.; Langevin, Y.; Palumbo, P.; Piccioni, G.; Sarri, G.; Titov, D.; Wahlund, J.-E.

    2015-10-01

    JUICE -JUpiter ICy moons Explorer -is the first large mission in the ESA Cosmic Vision 2015-2025 programme[1]. The mission was selected in May 2012 and adopted in November 2014. The implementation phase starts in July 2015, following the selection of the prime industrial contractor. Planned for launch in June 2022 and arrival at Jupiter in October 2029, it will spend at least three years making detailed observations of Jupiter and three of its largest moons, Ganymede, Callisto and Europa.

  3. Study of Power Options for Jupiter and Outer Planet Missions

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Fincannon, James

    2015-01-01

    Power for missions to Jupiter and beyond presents a challenging goal for photovoltaic power systems, but NASA missions including Juno and the upcoming Europa Clipper mission have shown that it is possible to operate solar arrays at Jupiter. This work analyzes photovoltaic technologies for use in Jupiter and outer planet missions, including both conventional arrays, as well as analyzing the advantages of advanced solar cells, concentrator arrays, and thin film technologies. Index Terms - space exploration, spacecraft solar arrays, solar electric propulsion, photovoltaic cells, concentrator, Fresnel lens, Jupiter missions, outer planets.

  4. Jupiter, a new Drosophila protein associated with microtubules.

    PubMed

    Karpova, Nina; Bobinnec, Yves; Fouix, Sylvaine; Huitorel, Philippe; Debec, Alain

    2006-05-01

    In this study we describe a novel Drosophila protein Jupiter, which shares properties with several structural microtubule-associated proteins (MAPs) including TAU, MAP2, MAP4. Jupiter is a soluble unfolded molecule with the high net positive charge, rich in Glycine. It possesses two degenerated repeats around the sequence PPGG, separated by a Serine-rich region. Jupiter associates with microtubules in vitro and, fused with the green fluorescent protein (GFP), is an excellent marker to follow microtubule dynamics in vivo. In a jupiter transgenic Drosophila strain generated by the "protein-trap" technique, Jupiter:GFP fusion protein localizes to the microtubule network through the cell cycle at the different stages of development. We found particularly high Jupiter:GFP concentrations in the young embryo, larval nervous system, precursors of eye photoreceptors and adult ovary. Moreover, from jupiter:gfp embryos we have established two permanent cell lines presenting strongly fluorescent microtubules during the whole cell cycle. In these cells, the distribution of the Jupiter:GFP fusion protein reproduces microtubule behavior upon treatment by the drugs colchicine and taxol. The jupiter cell lines and fly strain should be of wide interest for biologists interested in in vivo analysis of microtubule dynamics.

  5. The Juno Mission and the Origin of Jupiter

    NASA Astrophysics Data System (ADS)

    Bolton, Scott; Owen, Toby; Stevenson, David; Ingersoll, Andy; Connerney, Jack; Janssen, Michael; Folkner, William

    2015-04-01

    The Juno mission is the second mission in NASA's New Frontiers program. Launched in August 2011, Juno arrives at Jupiter in July 2016. Juno science goals include the study of Jupiter's origin, interior structure, deep atmosphere, aurora and magnetosphere. Jupiter's formation is fundamental to the evolution of our solar system and to the distribution of volatiles early in the solar system's history. Juno's measurements of the abundance of Oxygen and Nitrogen in Jupiter's atmosphere, and the detailed maps of Jupiter's gravity and magnetic field structure will constrain theories of early planetary development. Juno's orbit around Jupiter is a polar elliptical orbit with perijove approximately 5000 km above the visible cloud tops. The payload consists of a set of microwave antennas for deep sounding, magnetometers, gravity radio science, low and high energy charged particle detectors, electric and magnetic field radio and plasma wave experiment, ultraviolet imaging spectrograph, infrared imager and a visible camera. The Juno design enables the first detailed investigation of Jupiter's interior structure, and deep atmosphere as well as the first in depth exploration of Jupiter's polar magnetosphere. The Juno mission design, science goals, and measurements related to the origin of Jupiter will be presented.

  6. Reporting explained variance

    NASA Astrophysics Data System (ADS)

    Good, Ron; Fletcher, Harold J.

    The importance of reporting explained variance (sometimes referred to as magnitude of effects) in ANOVA designs is discussed in this paper. Explained variance is an estimate of the strength of the relationship between treatment (or other factors such as sex, grade level, etc.) and dependent variables of interest to the researcher(s). Three methods that can be used to obtain estimates of explained variance in ANOVA designs are described and applied to 16 studies that were reported in recent volumes of this journal. The results show that, while in most studies the treatment accounts for a relatively small proportion of the variance in dependent variable scores., in., some studies the magnitude of the treatment effect is respectable. The authors recommend that researchers in science education report explained variance in addition to the commonly reported tests of significance, since the latter are inadequate as the sole basis for making decisions about the practical importance of factors of interest to science education researchers.

  7. ESO Observations of New Moon of Jupiter

    NASA Astrophysics Data System (ADS)

    2000-08-01

    Two astronomers, both specialists in minor bodies in the solar system, have performed observations with ESO telescopes that provide important information about a small moon, recently discovered in orbit around the solar system's largest planet, Jupiter. Brett Gladman (of the Centre National de la Recherche Scientifique (CNRS) and working at Observatoire de la Cote d'Azur, France) and Hermann Boehnhardt ( ESO-Paranal) obtained detailed data on the object S/1999 J 1 , definitively confirming it as a natural satellite of Jupiter. Seventeen Jovian moons are now known. The S/1999 J 1 object On July 20, 2000, the Minor Planet Center (MPC) of the International Astronomical Union (IAU) announced on IAU Circular 7460 that orbital computations had shown a small moving object, first seen in the sky in 1999, to be a new candidate satellite of Jupiter. The conclusion was based on several positional observations of that object made in October and November 1999 with the Spacewatch Telescope of the University of Arizona (USA). In particular, the object's motion in the sky was compatible with that of an object in orbit around Jupiter. Following the official IAU procedure, the IAU Central Bureau for Astronomical Telegrams designated the new object as S/1999 J 1 (the 1st candidate Satellite of Jupiter to be discovered in 1999). Details about the exciting detective story of this object's discovery can be found in an MPC press release and the corresponding Spacewatch News Note. Unfortunately, Jupiter and S/1999 J 1 were on the opposite side of the Sun as seen from the Earth during the spring of 2000. The faint object remained lost in the glare of the Sun in this period and, as expected, a search in July 2000 through all available astronomical data archives confirmed that it had not been seen since November 1999, nor before that time. With time, the extrapolated sky position of S/1999 J 1 was getting progressively less accurate. New observations were thus urgently needed to "recover

  8. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. II. A SATURN-JUPITER CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-08-10

    We carry out a series of high-resolution (1024 x 1024) hydrodynamic simulations to investigate the orbital evolution of a Saturn-Jupiter pair embedded in a gaseous disk. This work extends the results of our previous work by exploring a different orbital configuration-Jupiter lies outside Saturn (q < 1, where q {identical_to} M{sub i} /M{sub o} is the mass ratio of the inner planet and the outer one). We focus on the effects of different initial separations (d) between the two planets and the various surface density profiles of the disk, where {sigma} {proportional_to} r {sup -}{alpha}. We also compare the results of different orbital configurations of the planet pair. Our results show that (1) when the initial separation is relatively large (d>d {sub iLr}, where d {sub iLr} is the distance between Jupiter and its first inner Lindblad resonance), the two planets undergo divergent migration. However, the inward migration of Saturn could be halted when Jupiter compresses the inner disk in which Saturn is embedded. (2) Convergent migration occurs when the initial separation is smaller (d < d {sub iLr}) and the density slope of the disk is nearly flat ({alpha} < 1/2). Saturn is then forced by Jupiter to migrate inward where the two planets are trapped into mean motion resonances (MMRs), and Saturn may get very close to the central star. (3) In the case of q < 1, the eccentricity of Saturn could be excited to a very high value (e{sub S} {approx} 0.4-0.5) by the MMRs and the system could maintain stability. These results explain the formation of MMRs in the exoplanet systems where the outer planet is more massive than the inner one. It also helps us to understand the origin of the 'hot Jupiter/Saturn' with a highly eccentric orbit.

  9. HST hot Jupiter transmission spectral survey: The atmospheric circulation of a large hot Jupiter sample

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David Kent; Lewis, Nikole K.; Fortney, Jonathan; Marley, Mark; Showman, Adam P.

    2015-12-01

    Even as we move towards characterizing smaller and cooler exoplanets, hot Jupiters continue to be the best transiting planets for probing the atmospheric properties of exoplanets and refining current theory. Here we present results from a comprehensive atmospheric circulation study of nine transiting hot Jupiters that probe a wide range of planetary properties, including orbital distance, rotation rate, mass, radius, gravity and stellar insolation. We utilize these circulation models to aid in the interpretation of transmission spectra obtained using the Space Telescope Imaging Spectrograph (STIS) and Wide Field Camera 3 (WFC3) as a part of a large Hubble Space Telescope (HST) transmission spectral survey. These observations have shown a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. Our “grid” of models recovers trends shown in other parametric studies of hot Jupiters, particularly increased day-night temperature contrast with increasing equilibrium temperature and equatorial superrotation. Furthermore, we show that three-dimensional variations in temperature, particularly across the western and eastern terminators and from the equator to the pole, can vary by hundreds of Kelvin. This can result in vastly different cloud properties across the limb, which can lead to variations in transmission spectra. Finally, we comment on prospects with the James Webb Space Telescope (JWST) to further characterize hot Jupiters out to longer wavelengths.

  10. Natural radio emission of Jupiter as interferences for radar investigations of the icy satellites of Jupiter

    NASA Astrophysics Data System (ADS)

    Cecconi, B.; Hess, S.; Hérique, A.; Santovito, M. R.; Santos-Costa, D.; Zarka, P.; Alberti, G.; Blankenship, D.; Bougeret, J.-L.; Bruzzone, L.; Kofman, W.

    2012-02-01

    Radar instruments are part of the core payload of the two Europa Jupiter System Mission (EJSM) spacecraft: NASA-led Jupiter Europa Orbiter (JEO) and ESA-led Jupiter Ganymede Orbiter (JGO). At this point of the project, several frequency bands are under study for radar, which ranges between 5 and 50 MHz. Part of this frequency range overlaps with that of the natural jovian radio emissions, which are very intense in the decametric range, below 40 MHz. Radio observations above 40 MHz are free of interferences, whereas below this threshold, careful observation strategies have to be investigated. We present a review of spectral intensity, variability and sources of these radio emissions. As the radio emissions are strongly beamed, it is possible to model the visibility of the radio emissions, as seen from the vicinity of Europa or Ganymede. We have investigated Io-related radio emissions as well as radio emissions related to the auroral oval. We also review the radiation belts synchrotron emission characteristics. We present radio sources visibility products (dynamic spectra and radio source location maps, on still frames or movies), which can be used for operation planning. This study clearly shows that a deep understanding of the natural radio emissions at Jupiter is necessary to prepare the future EJSM radar instrumentation. We show that this radio noise has to be taken into account very early in the observation planning and strategies for both JGO and JEO. We also point out possible synergies with RPW (Radio and Plasma Waves) instrumentations.

  11. Natural radio emission of Jupiter as interferences for radar investigations of the icy satellites of Jupiter

    NASA Astrophysics Data System (ADS)

    Cecconi, B.; Hess, S.; Hérique, A.; Santovito, M. R.; Santos-Costa, D.; Zarka, P.; Alberti, G.; Blankenship, D.; Bougeret, J. L.; Bruzzone, L.; Kofman, W.

    2011-10-01

    Radar instruments are part of the core payload of the two Europa Jupiter System Mission (EJSM) spacecraft: NASA-led Jupiter Europa Orbiter (JEO) and ESA-led Jupiter Ganymede Orbiter (JGO). At this point of the project, several frequency bands are under study for radar, which ranges between 5MHz and 50MHz. Part of this frequency range overlaps with that of the natural Jovian radio emissions, which are very intense in the decametric range, below 40 MHz. Radio observations above 40 MHz are free of interferences, whereas below this threshold, careful observation strategies have to be investigated. We present a review of spectral intensity, variability and sources of these radio emissions. As the radio emission are strongly beamed, it is possible to model the visibility of the radio emissions, as seen from the vicinity of Europa or Ganymede. We have investigated Io-related radio emissions as well as radio emissions related to the auroral oval. We also review the radiation belts synchrotron emission characteristics. We present radio sources visibility products (dynamic spectra and radio source location maps, on still frames or movies), which can be used for operation planning. This study clearly shows that a deep understanding of the natural radio emissions at Jupiter is necessary to prepare the future EJSM radar instrumentation. We show that this radio noise has to be taken into account very early in the observation planning and strategies for both JGO and JEO. We also point out possible synergies with RPW (Radio and Plasma Waves) instrumentations.

  12. A Possibly Universal Red Chromophore for Jupiter

    NASA Astrophysics Data System (ADS)

    Sromovsky, Lawrence A.; Baines, Kevin; Fry, Patrick M.

    2016-10-01

    A new laboratory-generated chemical compound made from photodissociated ammonia (NH3) molecules reacting with acetylene (C2H2) was suggested as a possible coloring agent for Jupiter's Great Red Spot (GRS) by Carlson et al. (2016, Icarus 274, 106-115). Baines et al. (2016, AAS/DPS Meeting abstract) showed that the GRS spectrum measured by the visual channels of the Cassini VIMS instrument in 2000 could be accurately fit by a cloud model in which the chromophore appeared as small particles in a physically thin layer immediately above the main cloud layer of the GRS. Here we show that the same chromophore and similar layer structure can also provide close matches to the 0.4-1 micron spectra of many other cloud features on Jupiter, suggesting that this material may be a nearly universal chromophore responsible for the various degrees of red coloration on Jupiter. This is a robust conclusion, even for 12 percent changes in VIMS calibration and large uncertainties in the refractive index of the main cloud layer due to uncertain fractions of NH4SH and NH3 in its cloud particles. The chromophore layer can account for color variations among north and south equatorial belts, equatorial zone, and the Great Red Spot, by varying particle size from 0.12 to 0.29 micron and optical depth from 0.06 to 0.76. The total mass of the chromophore layer is much less variable than its optical depth, staying mainly within 6-10 micrograms/cm2 range, but is only about half that amount in the equatorial zone. We also found a depression of the ammonia volume mixing ratio in the two belt regions, which averaged 0.4-0.5 × 10-4 immediately below the ammonia condensation level, while the other regions averaged twice that value.LAS and PMF acknowledge support from NASA Grant NNX14AH40G.

  13. Recent observations of Jupiter's ring system

    NASA Astrophysics Data System (ADS)

    Showalter, M.; Burns, J.; de Pater, I.; Hamilton, D.; Horanyi, M.

    2003-04-01

    Jupiter's faint, dusty ring system has several distinct components: a thin main ring, an inner, vertically extended halo, and an outer, fainter pair of "gossamer" rings. This ring system illustrates the complex dynamics of dust after it is ejected from the local moons (Metis, Adrastea, Amalthea and Thebe) and/or embedded parent bodies, and then evolves orbitally under solar and electromagnetic perturbations. The ring system has been observed by four spacecraft (Voyagers 1 and 2, Galileo and Cassini), as well as from the Earth by ground-based observatories and the Hubble Space Telescope (HST). While each individual data set has very limited coverage and content, a complete description of the system is now emerging. This paper will provide a systematic overview of the ring system, based on the latest available data and dynamical models. In particular, the period December 2002 through February 2003 is providing a rare opportunity to watch Jupiter sweep through its full range of Earth-based phase angles while remaining nearly edge-on to the Earth. We will discuss the initial results of an observing program using HST in the visual and the Keck Telescope in the infrared. As the rings pass through opposition, the parent bodies surge in brightness while the dust grains do not; this should provide a new means to distinguish the two populations, better revealing their numbers and locations. Variations in halo thickness with wavelength will provide new information about the sizes and dynamics of the dust grains scattered by Jupiter's strong, inner magnetic field. We will also seek out structures near the outer edge of Amalthea's gossamer ring, hinted at in previous data, which illustrate the dynamics of these dust grains immediately after their initial ejection into the ring.

  14. Organo-Nitrogen Reactions on Jupiter

    NASA Astrophysics Data System (ADS)

    Lamothe, V. L.; Moses, J. I.

    2000-10-01

    Because the altitude regions for CH4 and NH3 photodissociation are physically separated from each other in the Jovian atmosphere, the possibility of forming organo-nitrogen compounds on Jupiter has been an uncertain problem [1,2,3,4,5]. Carbon- and nitrogen-bearing species do not interact significantly in laboratory experiments involving ultraviolet irradiation of CH4-NH3-H2 mixtures [6,7]. However, HCN and a variety of complex organo-nitrogen molecules are produced when methane in the above experiments is replaced by unsaturated hydrocarbons such as C2H2 or CH3C2H [8,9]. To determine the formation efficiency of organo-nitrogen compounds on Jupiter, we have added the reaction schemes proposed by [3,8,9] to a photochemical model of the Jovian troposphere and stratosphere. We find that HCN does not form in observable quantities unless a large tropospheric source of C2H2 exists (e.g., via lightning-induced chemistry, see [10]). Organo-nitrogen reactions are unlikely to be important on Jupiter --- chromophores are most likely due to inorganic compounds. References: [1] Strobel, D. F. (1973), J. Atmos. Sci. 30, 1205; [2] Kaye, J. A., and D. F. Strobel (1983a), Icarus\\ 55, 399; [3] Kaye, J. A., and D. F. Strobel (1983b), Icarus\\ 54, 417; [4] Tokunaga, A. T. et al./ (1981), Icarus\\ 48, 283; [5] Bézard, B. et al./ (1995), Icarus\\ 118, 384; [6] Raulin, F. et al. (1979), Icarus\\ 38, 358; [7] Ferris, J. P., and J. Y. Morimoto (1981), Icarus\\ 48, 118; [8] Ferris, J. P., and Y. Ishikawa (1988), J. Am. Chem. Soc. 110, 4306; [9] Ferris, J. et\\ al. (1992), Icarus\\ 95, 54; [10] Bétremieux, Y., and R. V. Yelle (1999), BAAS\\ 31, 1180.

  15. THERMAL PROCESSES GOVERNING HOT-JUPITER RADII

    SciTech Connect

    Spiegel, David S.; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2013-07-20

    There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (1) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (2) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (3) the degree of heat redistribution to the nightside; and (4) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphere and/or convective interior in inflating hot Jupiters. Among our conclusions are that (1) the most highly irradiated planets cannot stably have uB {approx}> 10 km s{sup -1} G over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (2) that ohmic heating cannot in and of itself lead to a runaway in planet radius.

  16. Reigniting the Debate: First Spectroscopic Evidence for Stratospheres In Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Mandell, Avi M.; Haynes, Korey; Madhusudhan, Nikku; Deming, Drake; Knutson, Heather

    2015-12-01

    Hot Jupiters represent an extreme end of the exoplanet distribution: they orbit very close to their host stars, which subjects them to an intense heating from stellar radiation. An inverted temperature structure (i.e. a stratosphere) was an early observable prediction from atmospheric models of these planets, which demonstrated that high-temperature absorbers such as TiO and VO could reprocess incident UV/visible irradiation to heat the upper layers of the atmosphere.Evidence for such thermal inversions began with the first secondary eclipse measurements of transiting hot Jupiters taken with the IRAC camera on Spitzer, offering the chance to physical processe at work in the atmospheres of hot exoplanets. However, these efforts have been stymied by recent revelations of significant systematic biases and uncertainties buried within older Spitzer results, calling into question whether or not temperature inversions are actually present in hot Jupiters.We have recently published spectroscopy of secondary eclipses of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is one of the most highly irradiated hot Jupiters discovered to date and orbits a relatively inactive A star, making it an excellent candidate for eclipse spectroscopy at NIR wavelengths (1.1 - 1.7 µm). We find that a fit to combined data from HST, Spitzer and ground-based photometry can rule out models without a temperature inversion; additionally, we find that our measured spectrum displays excess in the measured flux toward short wavelengths that is best explained as emission from TiO.This discovery re-opens the debate on the presence and origin of stratospheres in hot Jupiters, but it also confirms that the combination of HST spectroscopy and a robust analysis of Spitzer and ground-based photometry can conclusively detect thermally inverted atmospheres

  17. Deep Plume Interaction with Gas Giant Weather Layers: Applications to Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    O'Neill, M. E.; Kaspi, Y.; Galanti, E.

    2015-12-01

    The weather layers of Jupiter and Saturn receive both solar radiation and heat from the deep interior. Currently, numerical models fall into two broad categories: Deep, dry and convecting interior models that lack a stably stratified troposphere above, or thin shells that represent only a troposphere, with parameterized heating from the lower boundary. Here we present the results from a new coupled model that allows resolved deep convective plumes to interact with a stable "weather layer". We demonstrate the relative importance of a stable tropospheric lapse rate and the magnitude of bottom heating on the strength and depth of the jets. Studies of this kind will benefit understanding of Jupiter's dynamics, in particular the depth of the cloud-level jets, in advance of Juno's 2016 arrival. Moreover, the difference between Saturn and Jupiter is explored using a parameter sweep of tropospheric stability, which acts as a proxy for tropospheric water abundance. We provide corresponding odd and high harmonic gravity fields, which will be a measurable quantity by Juno and Cassini.

  18. Voyager telecommunications: the broadcast from jupiter.

    PubMed

    Edelson, R E; Madsen, B D; Davis, E K; Garrison, G W

    1979-06-01

    Sweeping past Jupiter, the Voyager 1 spacecraft presages a new era in the exploration of the solar system. Not since the TV return from Apollo has a spacecraft returned information of such volume and pictures of such startling clarity. Yet this feat was accomplished from a distance 1770 times as great as that of the lunar adventure. The communication system responsible for this remarkable achievement is a oompilation of elements ranging from tiny integrated circuits to enormous ground antennas. This article seeks to describe the way in which data are returned from these fascinating, faraway bodies and to convey the excitement of the engineering work that supports our scientific endeavors.

  19. Parachute design for Galileo Jupiter entry probe

    NASA Technical Reports Server (NTRS)

    Rodier, R. W.; Thuss, R. C.; Terhune, J. E.

    1981-01-01

    This paper discusses the parachute subsystem used on an atmospheric entry probe that will descend through the clouds of Jupiter. The entry probe is a part of the Galileo Project to be launched in 1985 aboard the Space Shuttle; the entry probe will encounter the planet in 1988. The parachute subsystem consists of a pilot parachute and a main parachute, and both are of conventional conical ribbon design. Key considerations in the design of the parachutes and a summary of the parachute subsystem test program, which includes two air drop tests and a systems drop test (balloon launched), are presented.

  20. Equatorial Oscillations in Jupiter's and Saturn's Atmospheres

    NASA Technical Reports Server (NTRS)

    Flasar, F. Michael; Guerlet, S.; Fouchet, T.; Schinder, P. J.

    2011-01-01

    Equatorial oscillations in the zonal-mean temperatures and zonal winds have been well documented in Earth's middle atmosphere. A growing body of evidence from ground-based and Cassini spacecraft observations indicates that such phenomena also occur in the stratospheres of Jupiter and Saturn. Earth-based midinfrared measurements spanning several decades have established that the equatorial stratospheric temperatures on Jupiter vary with a cycle of 4-5 years and on Saturn with a cycle of approximately 15 years. Spectra obtained by the Composite Infrared Spectrometer (CIRS) during the Cassini swingby at the end of 2000, with much better vertical resolution than the ground-based data, indicated a series of vertically stacked warm and cold anomalics at Jupiter's equator; a similar structurc was seen at Saturn's equator in CIRS limb measurements made in 2005, in the early phase of Cassini's orbital tour. The thermal wind equation implied similar patterns of mean zonal winds increasing and decreasing with altitude. On Saturn the peak-to-pcak amplitude of this variation was nearly 200 meters per second. The alternating vertical pattern of wanner and colder cquatorial tcmperatures and easterly and westerly tendencies of the zonal winds is seen in Earth's equatorial oscillations, where the pattern descends with time, The Cassini Jupiter and early Saturn observations were snapshots within a limited time interval, and they did not show the temporal evolution of the spatial patterns. However, more recent Saturn observations by CIRS (2010) and Cassini radio-occultation soundings (2009-2010) have provided an opportunity to follow the change of the temperature-zonal wind pattern, and they suggest there is descent, at a rate of roughly one scale height over four years. On Earth, the observed descent in the zonal-mean structure is associated with the absorption of a combination of vertically propagating waves with easlerly and westerly phase velocities. The peak-to-peak zonal wind

  1. Jupiter's Tidal Q: The Range of Uncertainty

    NASA Astrophysics Data System (ADS)

    Greenberg, Richard; Barnes, R.; Jackson, B.

    2008-09-01

    Jupiter's Q, which quantifies the net effect of poorly understood dissipative processes, is central to the physical and orbital history of the Galilean satellites and to studies of extra-solar planets. A standard procedure for determining orbits from observations of extra-solar planets is to estimate e-damping times, using for Q a "commonly accepted value” 105-106, based on supposed constraints on Jupiter's Q: If the damping time is short, orbits are assumed circular; if the data nevertheless require a finite e, it is attributed to perturbations by unseen planets. But those now-standard procedures are flawed because, in fact, there are no firm constraints on Jupiter's Q. Given the dynamics of the system and its Laplace resonance, knowledge of the tidal dissipation rate in Io (from heat flux) and of Io's orbital acceleration dn1/dt (from mutual occultations and eclipses) should determine the effective value of QJ. If the Laplace resonance were in an equilibrium steady-state, then either one of those measured values yield QJ. Aksnes and Franklin's ("A&F's” 2001) solution for dn1/dt of 3.6x10-10/yr and McEwen et al.'s (1992) Io heat flux 1.3x1014W, gives QJ=2x105, the solution A&F highlighted. However, slight changes from those measured values, well within the uncertainty range, would yield infinite QJ. Another fit to the mutual event data allowed dn1/dt=0, but A&F rejected this result because the implied QJ ( 3x104) was outside the conventionally accepted range. In fact, that range is based on the steady-state condition of the resonance (placing an upper limit on QJ) and on the assumption that dn1/dt<0; (which gives a lower limit), both of which are ruled out by A&F's results. Our study of tidal evolution of "hot Jupiters” (Jackson et al. 2008) suggests typical Q values of 106.5, somewhat above the widely assumed range, but below the real upper limit (infinity) for Jupiter.

  2. Magnetospheres of Jupiter, Saturn, and Uranus

    SciTech Connect

    Connerney, J.E.P.

    1987-04-01

    The results published by U.S. scientists during 1983-1986 from studies related to the magnetospheres of Jupiter, Saturn, and Uranus are discussed. Consideration is given to the magnetic fields of these planets, charged particle environments, the interactions between the planetary rings and planetary satellites, the solar wind interactions, radio emissions, and auroras. Special attention is given to observations of (1) a small flux of energetic electrons and protons in the otherwise radiation-free environment in the magnetosphere under the rings of Saturn (interpreted as interactions of Galactic cosmic rays with the rings), (2) spokes, and (3) Saturn ring erosion.

  3. The Pioneer Jupiter magnetic control program.

    NASA Technical Reports Server (NTRS)

    Sanders, N. L.; Broce, R. D.; Inouye, G. T.

    1972-01-01

    The Pioneer Jupiter spacecraft was required to have a sufficiently small magnetic field that accurate interplanetary-magnetic field measurements would not be compromised. In order to control the magnetic field throughout the program a running account of spacecraft magnetic fields was maintained by means of a periodically updated magnetic model. This model was used to make economic tradeoffs in subsystem magnetic moments within the allowed magnetic budget. The program was culminated with a measurement of the magnetic field of the spacecraft. A description of the magnetic tests and a comparison with estimates made with the magnetic model are also presented.

  4. Flyby Delivers Multiple Deep Jupiter Probes

    NASA Technical Reports Server (NTRS)

    Spilker, T. R.; Hubbard, W. B.; Ingersoll, A. P.

    2001-01-01

    In situ probes are the most reliable means for sampling composition and conditions deep in giant planet atmospheres. While exceeding its baseline mission, the Galileo probe entered a distinctly non-representative region of Jupiter (a 'hot spot') and apparently did not measure the full deep abundances of such important species as H2O and H2S, whose measured abundances were still increasing at the deepest datum. Multiple deep (approx. 100 bar) in situ probes minimize the hot spot risk, and address spatial variations and deep constituent abundances. Additional information is contained in the original extended abstract.

  5. Mariner Jupiter/Saturn 1977 navigation strategy

    NASA Technical Reports Server (NTRS)

    Mckinley, E. L.; Van Allen, R. E.

    1975-01-01

    This paper presents selected navigational aspects of the Mariner Jupiter/Saturn 1977 mission. Emphasis is given to the trajectory correction strategy. In addition to science return and propellant costs, specific considerations affecting the strategy include a large number of candidate trajectories, relatively close satellite flybys, use of trajectory correction maneuvers for trajectory shaping, and the requirement for an optical data type to achieve precision satellite encounters. Finally, important error sources and mission constraints are identified, and their impact on the strategy is discussed.

  6. Planetary Systems: Crossing the Jupiter Threshold

    NASA Astrophysics Data System (ADS)

    Marcy, G. W.; Butler, R. P.

    1995-05-01

    We describe stellar Doppler measurements with a precision of 3 m s() -1, cabable of detecting extra-solar planets having masses less than one Jupiter-mass. No planetary systems around main sequence stars have yet been detected, nor does there exist a compelling detection of a brown dwarf, as a stellar companion or otherwise. Several groups are engaged in detecting planetary systems by using precise radial velocities to detect the wobble of the host star (cf. Campbell and Walker, 1988, ApJ,331,902 ; Cochran and Hatzes (1994, in ``Planetary Systems: Formation, Evolution, and Detection'', Kluwer Acad.). Among current search efforts, the Lick Observatory Planetary Search is extensive in both sample size and span of spectra types (Marcy and Butler, 1992, PASP,104,270). The project consists of a Doppler survey of 100 main sequence stars of spectral type, F, G, K, and M. The Lick Obs. full--format echelle gathers all Doppler information from 5000 to 5800 Ang. The wavelength calibration is accomplished with a gaseous iodine absorption cell placed at the slit of the Hamilton spectrometer which superimposes sharp I_2 lines on the stellar spectrum. The I_2 lines also provide the PSF of the spectrometer. A great breakthrough has occurred in the Doppler precision as a result of the improved Schmidt camera on the Hamilton. The Lick echelle now boasts a PSF with FWHM = 1.25 pixels for a narrow (0.3 arcsec) slit. The Doppler precision achieved is 3 m s() -1, based on velocity scatter during the past 5 months in our standard star, tau Ceti (G8V) . The velocities exhibit a standard deviation of 4 m s() -1 per exposure. However, we routinely obtain 4 quick exposures of the brightest target stars on our survey and average the 4 velocities. Such averaging for tau Ceti velocities yields a scatter of 3 m s() -1 due to errors in our Doppler measurements. For comparison, our Jupiter perturbs the Sun by 12.5 m s() -1 rendering Jupiter--like planets detectable at the 4--sigma level, even for

  7. Jupiter Europa Orbiter Architecture Definition Process

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert; Shishko, Robert

    2011-01-01

    The proposed Jupiter Europa Orbiter mission, planned for launch in 2020, is using a new architectural process and framework tool to drive its model-based systems engineering effort. The process focuses on getting the architecture right before writing requirements and developing a point design. A new architecture framework tool provides for the structured entry and retrieval of architecture artifacts based on an emerging architecture meta-model. This paper describes the relationships among these artifacts and how they are used in the systems engineering effort. Some early lessons learned are discussed.

  8. Mission to Jupiter. [Pioneer 10 and 11 space probes

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Pioneer 10 and Pioneer 11 space probes and their missions to Jupiter are discussed along with the experiments and investigations which will be conducted onboard. Jupiter's atmosphere, its magnetic fields, radiation belts, the spacecraft instruments, and the Jovian system will be investigated. Educational study projects are also included.

  9. Forum on Concepts and Approaches for Jupiter Icy Moons Orbiter

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The papers presented at this conference primarily discuss instruments and techniques for conducting science on Jupiter's icy moons, and geologic processes on the moons themselves. Remote sensing of satellites, cratering on satellites, and ice on the surface of Europa are given particular attention. Some papers discuss Jupiter's atmosphere, or exobiology.

  10. Narrow-band photography of Jupiter and Saturn.

    NASA Technical Reports Server (NTRS)

    Fountain, J. W.

    1973-01-01

    An IR-sensitive vidicon was used in the 1 to 2 mu region, with narrow-bandwidth filters, for Jupiter photographs taken in April, 1971, and Saturn photographs taken in December, 1970. The changes in limb darkening and surface details observed at different wavelengths are discussed. The 37 Jupiter photographs and the 38 Saturn photographs are included.

  11. A low mass for Mars from Jupiter's early gas-driven migration.

    PubMed

    Walsh, Kevin J; Morbidelli, Alessandro; Raymond, Sean N; O'Brien, David P; Mandell, Avi M

    2011-07-14

    Jupiter and Saturn formed in a few million years (ref. 1) from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only ∼100,000 years (ref. 2). Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later, and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 au is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 au, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 au; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 au and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.

  12. Resonance locking as the source of rapid tidal migration in the Jupiter and Saturn moon systems

    NASA Astrophysics Data System (ADS)

    Fuller, Jim; Luan, Jing; Quataert, Eliot

    2016-10-01

    The inner moons of Jupiter and Saturn migrate outwards due to tidal energy dissipation within the planets, the details of which remain poorly understood. We demonstrate that resonance locking between moons and internal oscillations of the planet can produce rapid tidal migration. Resonance locking arises due to the structural evolution of the planet and typically produces an outward migration rate comparable to the age of the solar system. Resonance locking predicts a similar migration timescale but a different effective tidal quality factor Q governing the migration of each moon. It also predicts nearly constant migration timescales a function of semi-major axis, such that effective Q values were larger in the past. Recent measurements of Jupiter and Saturn's moon systems find effective Q values that are much smaller than expected (and are different between moons), and which correspond to migration timescales of ~10 Gyr. If confirmed, the measurements are broadly consistent with resonance locking as the dominant source of tidal dissipation in Jupiter and Saturn. Resonance locking also provides solutions to several problems posed by current measurements: it naturally explains the exceptionally small Q governing Rhea's migration, it allows the large heating rate of Enceladus to be achieved in an equilibrium eccentricity configuration, and it resolves evolutionary problems arising from present-day migration/heating rates.

  13. Spin-orbit coupling and the production of misaligned hot Jupiters via Lidov-Kozai oscillations

    NASA Astrophysics Data System (ADS)

    Storch, Natalia I.; Anderson, Kassandra R.; Lai, Dong

    2015-12-01

    Many hot Jupiter systems exhibit misalignment between the orbital axis of the planet and the spin axis of its host star. While this misalignment could be primordial in nature, a large fraction of hot Jupiters are found in systems with distant stellar companions, and thus could have undergone Lidov-Kozai (LK) oscillations and acquired their misalignment dynamically. Here we present a study of the effect of spin-orbit coupling during LK oscillations, and the resulting spin-orbit misalignment angle distributions. We show that spin-orbit coupling induces complex, often chaotic, behavior in the spin axis of the host star, and that this behavior depends significantly on the mass of the planet and the properties of the host star (mass and spin history). We develop a semi-analytical framework that successfully explains most of the possible stellar spin behaviors. We then present a comprehensive population synthesis of hot Jupiters created via the LK mechanism, and discuss their possible observable signatures.

  14. A Low Mass for Mars from Jupiter's Early Gas-Driven Migration

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin J.; Morbidelli, Alessandro; Raymond, Sean N.; O'Brien, David P.; Mandell, Avi M.

    2011-01-01

    Jupiter and Saturn formed in a few million years from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only approximately 100,000 years. Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 AU is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 AU, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 AU; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 AU and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.

  15. Resonance locking as the source of rapid tidal migration in the Jupiter and Saturn moon systems

    NASA Astrophysics Data System (ADS)

    Fuller, Jim; Luan, Jing; Quataert, Eliot

    2016-06-01

    The inner moons of Jupiter and Saturn migrate outwards due to tidal energy dissipation within the planets, the details of which remain poorly understood. We demonstrate that resonance locking between moons and internal oscillation modes of the planet can produce rapid tidal migration. Resonance locking arises due to the internal structural evolution of the planet and typically produces an outward migration rate comparable to the age of the Solar system. Resonance locking predicts a similar migration time-scale but a different effective tidal quality factor Q governing the migration of each moon. The theory also predicts nearly constant migration time-scales a function of semimajor axis, such that effective Q values were larger in the past. Recent measurements of Jupiter and Saturn's moon systems find effective Q values that are smaller than expected (and are different between moons), and which correspond to migration time-scales of ˜10 Gyr. If confirmed, the measurements are broadly consistent with resonance locking as the dominant source of tidal dissipation in Jupiter and Saturn. Resonance locking also provides solutions to several problems posed by current measurements: it naturally explains the exceptionally small Q governing Rhea's migration, it allows the large heating rate of Enceladus to be achieved in an equilibrium eccentricity configuration, and it resolves evolutionary problems arising from present-day migration/heating rates.

  16. A low mass for Mars from Jupiter's early gas-driven migration.

    PubMed

    Walsh, Kevin J; Morbidelli, Alessandro; Raymond, Sean N; O'Brien, David P; Mandell, Avi M

    2011-07-14

    Jupiter and Saturn formed in a few million years (ref. 1) from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only ∼100,000 years (ref. 2). Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later, and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 au is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 au, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 au; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 au and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought. PMID:21642961

  17. System III variations in apparent distance of Io plasma torus from Jupiter

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.; Sandel, B. R.

    1992-01-01

    System III variations in apparent distance of the Io plasma torus from Jupiter are examined on the basis of data obtained from UVS scans across Jupiter's satellite system. The displacement of the dawn and dusk ansae are found to be unexpectedly complex. The displacements are unequal and both ansae are in motion with the motion of the approaching ansa being the lesser of the two. The radial motions, as measured from either the center of Jupiter or the offset-tilted dipole, are of unequal magnitude and have the System III periodicity. It is concluded that the cross-tail electric field that causes these torus motions is concentrated on the dusk ansa, varied with the System III period, and shows magnetic-anomaly phase control. It is found that the dawn-dust asymmetry in brightness is not explained simply by the cross-tail electric field. It is concluded that there is a heating mechanism that causes the dusk side of the Io plasma torus to be brighter than the dawn side.

  18. Energetic-ion acceleration and transport in the upstream region of Jupiter: Voyager 1 and 2

    NASA Technical Reports Server (NTRS)

    Baker, D. N.; Zwickl, R. D.; Carbary, J. F.; Krimigis, S. M.; Lepping, R. P.

    1982-01-01

    Long-lived upstream energetic ion events at Jupiter appear to be very similar in nearly all respects to upstream ion events at Earth. A notable difference between the two planetary systems is the enhanced heavy ion compositional signature reported for the Jovian events. This compositional feature has suggested that ions escaping from the Jovian magnetosphere play an important role in forming upstream ion populations at Jupiter. In contrast, models of energetic upstream ions at Earth emphasize in situ acceleration of reflected solar wind ions within the upstream region itself. Using Voyager 1 and 2 energetic ( approximately 30 keV) ion measurements near the magnetopause, in the magnetosheath, and immediately upstream of the bow shock, the compositional patterns are examined together with typical energy spectra in each of these regions. A model involving upstream Fermi acceleration early in events and emphasizing energetic particle escape in the prenoon part of the Jovian magnetosphere late in events is presented to explain many of the features in the upstream region of Jupiter.

  19. Explaining cloud chamber tracks

    SciTech Connect

    Broyles, A.A.

    1992-06-16

    The operation of many detection devices is usually explained in terms of the ionization tracks produced by particles despite the fact that the corresponding incident wave functions extended over the entire sensitive regions of the detectors. The mechanisms by which the wave function appears to collapse to a track is analyzed here.

  20. Explaining the Interpretive Mind.

    ERIC Educational Resources Information Center

    Brockmeier, Jens

    1996-01-01

    Examines two prominent positions in the epistemological foundations of psychology--Piaget's causal explanatory claims and Vygotsky's interpretive understanding; contends that they need to be placed in their wider philosophical contexts. Argues that the danger of causally explaining cultural practices through which human beings construct and…

  1. Explaining Immigrant Naturalization.

    ERIC Educational Resources Information Center

    Yang, Philip Q.

    1994-01-01

    Proposes a broad analytical framework in the study of immigrant naturalization that incorporates an immigrant's individual characteristics with the larger social contexts in the country of origin and the country of destination to explain the likelihood of citizenship acquisition. Results testing of this framework show that such considerations are…

  2. Calculated limits for particle fluxes in Jupiter's Van Allen belts

    NASA Technical Reports Server (NTRS)

    Haffner, J.

    1972-01-01

    Electron and proton fluxes in Jupiter's radiation belts are calculated, along with the envelopes of dose rates. The following assumptions are made: the particles in the Jupiter belts are influenced only by the magnetic field of the planet; the particles act correspondingly to the particles in the Earth's belts and the Earth's belts can be used as a model; the magnetic field of Jupiter is essentially a dipole; the radiation of a decimetric nature received from Jupiter is synchrotron radiation due to the electrons, and to a first approximation it is emitted isotropically; and the strength of the emission in the decimetric wavelength range gives an upper bound considering how strong the field can be and how many electrons there are. The point dose rates for tissue and 0.1 gram/cm aluminum shielding at about 3 Jupiter radii are 10000 rads/hr for electrons and 1000 rads/hr for protons.

  3. Periodic changes of the activity of processes in Jupiter's atmosphere

    NASA Astrophysics Data System (ADS)

    Vidmachenko, A. P.

    2016-10-01

    Variations of the Earth jovimagnetic latitude on Jupiter are preferred in solar-driven changes of reflective properties of clouds and haze on Jupiter. Because of the orbit eccentricity (e=0,048450) the northern hemisphere receives 21% greater solar energy flow to the atmosphere, because Jupiter is in the perihelia near the time of the summer solstice. Results of our studies showed that the ratio of the brightness of the northern and southern tropical and temperate regions is evident factor of the photometric activity of the Jupiter's atmospheric processes. The obtained from the analysis of observational data for the period from 1962 to 2015 existence of variations of activity factor of the planet hemispheres with a period of 11.86 years has allowed us to talk about an existence of the seasonal reconstruction of the physical parameters of Jupiter's atmosphere.

  4. The role of Io in the dynamics of Jupiter's magnetosphere: A sandpile modelling approach.

    NASA Astrophysics Data System (ADS)

    Reed, J. J.; Jackman, C. M.; Freeman, M. P.

    2015-10-01

    Jupiter's magnetosphere is thought to be largely internally driven, by the combination of the loading of ~500 kg/s of plasma into the system by the volcanic moon Io, and the rapid rotation of the planet itself. Since we do not see a continuously expanding torus and magnetosphere, we would expect a long-term balance between the inflow of mass, primarily from Io, and the outflow of mass, via plasmoid release. Simple calculations, which attempt to match the mass-loading rate from Io with the amount of mass lost via large-scale tail reconnection events, indicate a significant mass imbalance at Jupiter. This mass imbalance may be due to several reasons, including visibility issues linked to single spacecraft observations. This is where modelling can be a powerful tool. A single spacecraft can only expect to observe a global 'systemwide' event, where energy is redistributed across the entiresystem, with any certainty. While 'internal' events, with a more local redistribution of energy, are likely to be missed. Usingcomputational modeling we are able to'observe' an entire system at any time. Cellular automata (CA) based on robust physical parameters and rules can allow us to manipulate the inputs and drivers of magnetotail physics, and to explore the response of the system over a range of temporal and spatial scales. Here we examine the variability of the mass-loading and the response of our CA sandpile model to an analogous driving. We explore whether Jupiter's magnetospheric dynamics can be explained purely in terms of Io massloading. In particular we examine the difference between the small local events ("internal" avalanches) and larger global events ("systemwide" avalanches), and what this can tell us about the fate of mass in Jupiter's magnetosphere.

  5. Current Status of the 2008 Europa-Jupiter Study

    NASA Astrophysics Data System (ADS)

    Pappalardo, Robert; Lebreton, Jean-Pierre; Stankov, Anamarija; Greeley, Ronald; Blanc, Michel; Clark, Karla; Grunthaner, Paula; Falkner, Peter

    NASA and the ESA have embarked on a joint study of a mission to Europa and the Jupiter system. The Jupiter Joint Science Definition (JJSDT) team is providing science input to a Europa Orbiter mission study (run by NASA) and to the Jupiter Orbiter mission study (run by ESA). The JJSDT is defining the science content of the missions and working closely with the engineering team to define a mission concept that optimizes science, cost, and risk. Unique among the Jovian satellites, Europa is believed to shelter an ocean between its geodynamically active icy crust and its silicate mantle, one where the main conditions for habitability may be fulfilled. Europa is the astrobiological archetype for icy satellite habitability, with a warm, salty, water ocean with plausible chemical energy sources. It is also a geophysical wonderland of interrelated ice shell processes that are intimately related to the ocean and tides, and of complex interactions among its interior, surface, atmosphere, and particles and fields environments. The Europa Orbiter mission would investigate the habitability of this enigmatic satellite using gravity and remote sensing. To understand in a more generic way the habitability conditions around giant planets, we need to go beyond Europa itself and address two more general questions at the scale of the Jupiter system: to what extent is its possible habitability related to the initial conditions and formation scenario of the Jovian satellites? To what extent is it due to the way the Jupiter system works? ESA is investigating the possibility of a Jupiter Planetary Orbiter/Ganymede Orbiter, which would focus on the Jupiter system. Moreover, the NASA Europa Orbiter would orbit Jupiter for nearly 2 years using gravity assists of the icy Galilean satellites to lower its energy, providing the opportunity for significant Jupiter system science. This multi-platform and multi-target architecture, combined with its broadly multidisciplinary scientific dimension

  6. Explaining Autism: Its Discursive and Neuroanatomical Characteristics.

    ERIC Educational Resources Information Center

    Oller, John W., Jr.; Rascon, Dana

    This paper reviews the existing empirical research on autism in the context of the semiotic theories of Charles S. Peirce. His ideas of the generalized logic of relations are seen as explaining the unusual associations (or lack thereof) in autism. Concepts of "indices" or signs singling out distinct objects, and "adinity" or the number of distinct…

  7. Current thinking about Jupiter's magnetic anomaly

    NASA Astrophysics Data System (ADS)

    Grodent, D.; Gerard, J.-C.; Gustin, J.; Clarke, J. T.; Connerney, J. E.

    Repeated imaging of Jupiter's aurora has shown that the northern main oval has a distorted 'kidney bean' shape in the general range of 90-150o System III longitude, which appears unchanged since 1994. While it is more difficult to observe the conjugate regions in the southern aurora, no corresponding distortion appears in the south. Recent improved accuracy in locating the auroral footprint emission of Io has provided new information about the geometry of Jupiter's magnetic field in this and other areas. The persistent pattern of the main oval implies a disturbance of the local magnetic field, and the increased latitudinal separation of the locus of the Io footprint from the main oval implies a locally weaker field strength. The most recent images obtained with the Hubble Space Telescope Advance Camera for Surveys (ACS) allow us to complement previous observations with the location of the auroral footprints of Io, Europa, and Ganymede in the region of interest. Their footpaths vary in parallel and form a kink in the 90-150° S3 sector which strongly suggests the presence of a magnetic anomaly in this region.

  8. Jupiter's Equatorial Zone in Exaggerated Color

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This special color composite made from Voyager 2 narrow-angle frames taken on June 28, 1979, has been processed to exaggerate color differences within the naturally colorful Jovian atmosphere. Such processing makes detailed structure in the clouds more apparent. The dark belt across the upper portion of the photograph is the North Equatorial Belt. One of the largest of the long-lived dark features found along the northern edge of this belt is seen in the upper middle of the photograph. Jupiter's Equatorial Zone, which lies across the middle of the photograph, is characterized by a series of wisp-like plume features. The northern bluish edges of these plumes are thought to lie within deeper, warmer levels of the atmosphere. South of the Equatorial Zone lies the chaotic region of whiter clouds found west of the Great Red Spot. kilometers (6.4 million miles) from Jupiter. The smallest features visible in this photograph are about 190 kilometers (119 miles) across.

  9. The helium abundance of Jupiter from Voyager

    NASA Technical Reports Server (NTRS)

    Gautier, D.; Conrath, B.; Flasar, F. M.; Hanel, R. A.; Kunde, V. G.; Chedin, A.; Scott, N.

    1980-01-01

    Full disk measurements recorded 31 days before the Voyager 1 encounter with Jupiter by the radiometer of the infrared instrument, IRIS, indicate a geometric albedo of 0.274 + or - 0.013. Combining this measurement with the Pioneer derived phase integral of 1.25 and our error estimate of 0.1 yields a Jovian Bond albedo of 0.343 + or - 0.032. Infrared spectra recorded at the same time by the Michelson interferometer, along with a model extrapolation to low wave numbers not covered by the instrument, yield a thermal emission of (1.359 + or - 0.014) .001 W cm to the (-2) power. As in the case of the albedo measurement, the quoted errors in the emission measurement reflect estimates of systematic effects and are uncertain while the random component is negligible. From these measurements the internal heat flux of Jupiter is estimated to be (5.444 + or - 0.425) .0001 W cm to the (-2) power, and the energy balance defined as the ratio of emitted thermal to absorbed solar energy is 1.668 + or - 0.085.

  10. Absorption of trapped particles by Jupiter's moons

    NASA Technical Reports Server (NTRS)

    Hess, W. N.; Birmingham, T. J.; Mead, G. D.

    1973-01-01

    Absorption effects of the four innermost moons in the radial transport equations for electrons and protons in Jupiter's magnetosphere are presented. The phase space density n at 2 R sub J for electrons with equatorial pitch angles less than 69 deg is reduced by a factor of 4.2 x 1000 when lunar absorption is included in the calculation. For protons with equatorial pitch angles less than 69 deg, the corresponding reduction factor is 3.2 x 100000. The effect of the satellites becomes progressively weaker for both electrons and protons as equatorial pitch angles of pi/2 are approached, because the likelihood of impacting a satellite becomes progressively smaller. The large density decreases which we find at the orbits of Io, Europa, and Ganymede result in corresponding particle flux decreases that should be observed by spacecraft making particle measurements in Jupiter's magnetosphere. The characteristic signature of satellite absorption should be a downward pointing cusp in the flux versus radius curve at the L-value corresponding to each satellite.

  11. Fading of Jupiter's South Equatorial Belt

    NASA Technical Reports Server (NTRS)

    Sola, Michael A.; Orton, Glenn; Baines, Kevin; Yanamandra-Fisher, Padma

    2011-01-01

    One of Jupiter's most dominant features, the South Equatorial Belt, has historically gone through a "fading" cycle. The usual dark, brownish clouds turn white, and after a period of time, the region returns to its normal color. Understanding this phenomenon, the latest occurring in 2010, will increase our knowledge of planetary atmospheres. Using the near infrared camera, NSFCAM2, at NASA's Infrared Telescope Facility in Hawaii, images were taken of Jupiter accompanied by data describing the circumstances of each observation. These images are then processed and reduced through an IDL program. By scanning the central meridian of the planet, graphs were produced plotting the average values across the central meridian, which are used to find variations in the region of interest. Calculations using Albert4, a FORTRAN program that calculates the upwelling reflected sunlight from a designated cloud model, can be used to determine the effects of a model atmosphere due to various absorption, scattering, and emission processes. Spectra that were produced show ammonia bands in the South Equatorial Belt. So far, we can deduce from this information that an upwelling of ammonia particles caused a cloud layer to cover up the region. Further investigations using Albert4 and other models will help us to constrain better the chemical make up of the cloud and its location in the atmosphere.

  12. True Color of Jupiter's Great Red Spot

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Roughly true color image of the Great Red Spot of Jupiter as taken by the Galileo imaging system on June 26, 1996. Because the Galileo imaging system's wavelength sensitivities go beyond those of the human eye, this is only an approximation of what a human observer would have seen in place of the Galileo spacecraft. To simulate red as our eyes see it, the near-infrared filter (756 nm) image was used. To simulate blue as our eyes see it, the violet filter (410 nm) image was used. Finally, to simulate green as our eyes see it, a combination of 2/3 violet and 1/3 near-infrared was used. The result is an image that is similar in color to that seen when looking through a telescope at Jupiter with your eye, but allowing detail about 100 times finer to be visible! The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  13. Tidal Response of Preliminary Jupiter Model

    NASA Astrophysics Data System (ADS)

    Wahl, Sean M.; Hubbard, William B.; Militzer, Burkhard

    2016-11-01

    In anticipation of improved observational data for Jupiter’s gravitational field, from the Juno spacecraft, we predict the static tidal response for a variety of Jupiter interior models based on ab initio computer simulations of hydrogen–helium mixtures. We calculate hydrostatic-equilibrium gravity terms, using the non-perturbative concentric Maclaurin Spheroid method that eliminates lengthy expansions used in the theory of figures. Our method captures terms arising from the coupled tidal and rotational perturbations, which we find to be important for a rapidly rotating planet like Jupiter. Our predicted static tidal Love number, {k}2=0.5900, is ∼10% larger than previous estimates. The value is, as expected, highly correlated with the zonal harmonic coefficient J 2, and is thus nearly constant when plausible changes are made to the interior structure while holding J 2 fixed at the observed value. We note that the predicted static k 2 might change, due to Jupiter’s dynamical response to the Galilean moons, and find reasons to argue that the change may be detectable—although we do not present here a theory of dynamical tides for highly oblate Jovian planets. An accurate model of Jupiter’s tidal response will be essential for interpreting Juno observations and identifying tidal signals from effects of other interior dynamics of Jupiter’s gravitational field.

  14. Radio Jove: Jupiter Radio Astronomy for Citizens

    NASA Astrophysics Data System (ADS)

    Higgins, Charles; Thieman, J. R.; Flagg, R.; Reyes, F. J.; Sky, J.; Greenman, W.; Brown, J.; Typinski, D.; Ashcraft, T.; Mount, A.

    2014-01-01

    Radio JOVE is a hands-on educational activity that brings the radio sounds of the Sun, Jupiter, the Milky Way Galaxy, and terrestrial radio noise to students, teachers, and the general public. Participants may build a simple radio telescope kit, make scientific observations, and interact with professional radio observatories in real-time over the Internet. Our website (http://radiojove.gsfc.nasa.gov) includes science information, construction manuals, observing guides, and education resources for teachers and students. Radio Jove is continually expanding its participants with over 1800 kits sold to more than 70 countries worldwide. Recently some of our most dedicated observers have upgraded their Radio Jove antennas to semi-professional observatories. We have spectrographs and wide band antennas, some with 8 MHz bandwidth and some with dual polarization capabilities. In an effort to add to the science literature, these observers are coordinating their efforts to pursue some basic questions about Jupiter’s radio emissions (radio source locations, spectral structure, long term changes, etc.). We can compare signal and ionosphere variations using the many Radio Jove observers at different locations. Observers are also working with members of the Long Wavelength Array Station 1 (LWA1) radio telescope to coordinate observations of Jupiter; Radio Jove is planning to make coordinated observations while the Juno Mission is active beginning in 2015. The Radio Jove program is overviewed, its hardware and software are highlighted, recent sample observations are shown, and we demonstrate that we are capable of real citizen science.

  15. Orbital Evolution of Jupiter-Family Comets

    NASA Technical Reports Server (NTRS)

    Ipatov, S. I.; Mather, J. S.; Oegerle, William R. (Technical Monitor)

    2002-01-01

    We investigated the evolution for periods of at least 5-10 Myr of 2500 Jupiter-crossing objects (JCOs) under the gravitational influence of all planets, except for Mercury and Pluto (without dissipative factors). In the first series we considered N=2000 orbits near the orbits of 30 real Jupiter-family comets with period less than 10 yr, and in the second series we took 500 orbits close to the orbit of Comet 10P Tempel 2. We calculated the probabilities of collisions of objects with the terrestrial planets, using orbital elements obtained with a step equal to 500 yr and then summarized the results for all time intervals and all bodies, obtaining the total probability P(sub sigma) of collisions with a planet and the total time interval T(sub sigma) during which perihelion distance of bodies was less than a semimajor axis of the planet. The values of P = 10(exp 6)P(sub sigma)/N and T = T(sub sigma)/1000 yr are presented in Table together with the ratio r of the total time interval when orbits were of Apollo type (at e less than 0.999) to that of Amor type.

  16. The electron diffusion coefficient in Jupiter's magnetosphere

    NASA Technical Reports Server (NTRS)

    Birmingham, T.; Northrop, T.; Baxter, R.; Hess, W.; Lojko, M.

    1974-01-01

    A steady-state model of Jupiter's electron radiation belt is developed. The model includes injection from the solar wind, radial diffusion, energy degradation by synchrotron radiation, and absorption at Jupiter's surface. A diffusion coefficient of the form D sub RR/R sub J squared = k times R to the m-th power is assumed, and then observed data on synchrotron radiation are used to fit the model. The free parameters determined from this fit are m = 1.95 plus or minus 0.5, k = 1.7 plus or minus 0.5 x 10 to the 9th power per sec, and the magnetic moment of injected particles equals 770 plus or minus 300 MeV/G. The value of m shows quite clearly that the diffusion is not caused by magnetic pumping by a variable solar wind or by a fluctuating convection electric field. The process might be field line exchange driven by atmospheric-ionospheric winds; our diffusion coefficient has roughly the same radial dependence but is considerably smaller in magnitude than the upper bound diffusion coefficients recently suggested for this process by Brice and McDonough (1973) and Jacques and Davis (1972).

  17. Voyager telecommunications - The broadcast from Jupiter

    NASA Technical Reports Server (NTRS)

    Edelson, R. E.; Madsen, B. D.; Davis, E. K.; Garrison, G. W.

    1979-01-01

    The means by which the data collected by the Voyager 1 mission to Jupiter were returned to earth are presented. Radio links between the earth and the spacecraft are used for the transmission of both imaging and nonimaging telemetry from the spacecraft and commands from the earth and for radiometric observations of the spacecraft and its environment. Features which have lead to vast improvements in the capability of the Voyager telecommunications system over that of previous space probes include the use of X-band rather than S-band telemetry, a dual power X-band traveling wave tube amplifier, a 3.7 m spacecraft antenna and a single channel telemetry system with concatenated coding. Communications equipment at the three ground complexes of the Deep Space Network for telemetry reception includes 64 m steerable antennas, cryogenic maser preamplifiers and a phase-lock loop receiver. Voyager 1 has met or exceeded all of its telecommunications requirements, providing a 98% data return and a total of 2 x 10 to the 11th data bits during the Jupiter encounter.

  18. Evidence for aggregate particles in the atmospheres of Titan and Jupiter

    NASA Astrophysics Data System (ADS)

    West, R. A.; Smith, P. H.

    1991-04-01

    The present optical-property calculations for aggregate particles allow most of the photometric and polarimetric observations for the Titan atmosphere to be explainable in terms of aggregate particles, whose mean projected area equals that of an 0.14-micron radius sphere; these would contain monomers of near-0.06-micron radius. Such aggregate particles may further account for the observed optical properties of Jupiter's high-altitude haze, and could ultimately furnish an essential constraint on the Titan's coupled surface/atmosphere evolution.

  19. Dust as the cause of spots on Jupiter

    NASA Technical Reports Server (NTRS)

    Field, G. B.; Tozzi, G. P.; Stanga, R. M.

    1995-01-01

    The long-lived spots caused by the impact of fragments of Comet S-L 9 on Jupiter can be understood if clouds of dust are produced by the impact. These clouds reside in the stratosphere, where they absorb visible light that would ordinarily reflect from the cloud deck below, and reflect radiation at infrared wavelengths that would ordinarily be absorbed by atmospheric methane. Here we show that, provided that the nucleus of a fragment is composed substantially of silicates and has a diameter greater than about 0.4 km, dust in the required amounts will condense from the hot gas composed of cometary and Jovian material ejected from the site where the fragment entered, and the dust will be suspended in the stratosphere for long periods. Particles about 1 micron in radius can explain both the optical properties and longevities of the spots. According to our model, a silicate band should be present in the 10 - micron spectra of the spots.

  20. Observational Consequences of Hydrodynamic Flows on Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Langton, Jonathan; Laughlin, Gregory

    2007-03-01

    We use a grid-based shallow water model to simulate the atmospheric dynamics of the transiting hot Jupiter HD 209458b. Under the usual assumption that the planet is in synchronous rotation with zero obliquity, a steady state is reached with a well-localized cold spot centered 76° east of the antistellar point. This represents a departure from predictions made by previous simulations in the literature that used the shallow water formalism; we find that the disagreement is explained by the factor of 30 shorter radiative timescale used in our model. We also examine the case that the planet is in Cassini state 2, in which the expected obliquity is ~90°. Under these circumstances, a periodic equilibrium is reached, with the temperature slightly leading the solar forcing. Using these temperature distributions, we calculate disk-integrated bolometric infrared light curves from the planet. The light curves for the two models are surprisingly similar, despite large differences in temperature patterns in the two cases. In the zero-obliquity case, the intensity at the minimum is 66% of the maximum intensity, with the minimum occurring 72° ahead of transit. In the high-obliquity case, the minimum occurs 54° ahead of transit, with an intensity of 58% of the maximum.

  1. External Photoevaporation of the Solar Nebula: Jupiter's Noble Gas Enrichments

    NASA Astrophysics Data System (ADS)

    Monga, Nikhil; Desch, Steven

    2015-01-01

    We present a model explaining the elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne, and O are depleted, seven other elements show similar enrichments (~3 times solar, relative to H). Being volatile, Ar is difficult to fractionate from H2. We argue that external photoevaporation by far-ultraviolet (FUV) radiation from nearby massive stars removed H2, He, and Ne from the solar nebula, but Ar and other species were retained because photoevaporation occurred at large heliocentric distances where temperatures were cold enough (lsim 30 K) to trap them in amorphous water ice. As the solar nebula lost H, it became relatively and uniformly enriched in other species. Our model improves on the similar model of Guillot & Hueso. We recognize that cold temperatures alone do not trap volatiles; continuous water vapor production is also necessary. We demonstrate that FUV fluxes that photoevaporated the disk generated sufficient water vapor in regions <~ 30 K to trap gas-phase species in amorphous water ice in solar proportions. We find more efficient chemical fractionation in the outer disk: whereas the model of Guillot & Hueso predicts a factor of three enrichment when only <2% of the disk mass remains, we find the same enrichments when 30% of the disk mass remains. Finally, we predict the presence of ~0.1 M ⊕ of water vapor in the outer solar nebula and protoplanetary disks in H II regions.

  2. EXTERNAL PHOTOEVAPORATION OF THE SOLAR NEBULA: JUPITER's NOBLE GAS ENRICHMENTS

    SciTech Connect

    Monga, Nikhil; Desch, Steven

    2015-01-01

    We present a model explaining the elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne, and O are depleted, seven other elements show similar enrichments (∼3 times solar, relative to H). Being volatile, Ar is difficult to fractionate from H{sub 2}. We argue that external photoevaporation by far-ultraviolet (FUV) radiation from nearby massive stars removed H{sub 2}, He, and Ne from the solar nebula, but Ar and other species were retained because photoevaporation occurred at large heliocentric distances where temperatures were cold enough (≲ 30 K) to trap them in amorphous water ice. As the solar nebula lost H, it became relatively and uniformly enriched in other species. Our model improves on the similar model of Guillot and Hueso. We recognize that cold temperatures alone do not trap volatiles; continuous water vapor production is also necessary. We demonstrate that FUV fluxes that photoevaporated the disk generated sufficient water vapor in regions ≲ 30 K to trap gas-phase species in amorphous water ice in solar proportions. We find more efficient chemical fractionation in the outer disk: whereas the model of Guillot and Hueso predicts a factor of three enrichment when only <2% of the disk mass remains, we find the same enrichments when 30% of the disk mass remains. Finally, we predict the presence of ∼0.1 M {sub ⊕} of water vapor in the outer solar nebula and protoplanetary disks in H II regions.

  3. When Lack of Evidence Is Evidence of Lack.

    PubMed

    Pickering, Neil

    2015-12-01

    In their recent article "A Gentle Ethical Defence of Homeopathy," Levy, Gadd, Kerridge, and Komesaroff use the claim that "lack of evidence is not equivalent to evidence of lack" as a component of their ethical defence of homeopathy. In response, this article argues that they cannot use this claim to shore up their ethical arguments. This is because it is false. PMID:26631232

  4. The magnetic field and secular variation of Jupiter

    NASA Astrophysics Data System (ADS)

    Ridley, V. A.; Holme, R.

    2012-04-01

    Planetary dynamos, resulting from fluid flow in electrically conductive parts of their interior, are thought to be highly time dependent. Currently, our understanding of temporal variation of these fields is limited because we only have observations for one example, the Earth. To overcome this, data acquired by 6 NASA space missions between 1973-2003 are used to investigate possible time variation (secular variation) of Jupiter's magnetic field. Previous attempts to model jovimagnetic secular variation have been inconclusive or ineffective for a number of reasons, including limited data usage, inadequate consideration of the external current disk field and the modelling approach taken. We attempt to resolve these issues by using all data available within 12 Jovian radii, establishing and removing the current disk field for each individual orbit and taking a regularised minimum norm approach to modelling the internal planetary field. This approach allows construction of numerically stable models with constrained small-scale (high spherical harmonic degree) structure that directly fit the observations. Two models of Jupiter's magnetic field are presented: the first time-averaged over the whole dataset, whilst the second allows for linear time variation of the field. Comparison of these allow inferences to be made about jovimagnetic secular variation with our favoured model indicating a ~0.042%yr-1 decrease in the dipole magnetic moment over the investigated time period; this value is comparable with Earth (~0.06%yr-1). Simple models of jovian "core flow", while highly speculative, also show patterns not dissimilar from those of the Earth. These models are calculated with reference to the Jovian System III 1965.0 reference frame, itself defined by the magnetic field. Thus, some of the secular variation could result from inaccuracies in this determination; however, such an effect cannot explain all the observed secular variation. The constraint on changes in planetary

  5. Small inner companions of warm Jupiters: Lifetimes and legacies

    SciTech Connect

    Van Laerhoven, Christa; Greenberg, Richard

    2013-12-01

    Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

  6. The occultation of HIP 107302 by Jupiter

    NASA Astrophysics Data System (ADS)

    Christou, A. A.; Beisker, W.; Casas, R.; Schnabel, C.; Massallé, A.; Díaz-Martin, M. C.; Assafin, M.; Braga-Ribas, F.; Eppich, P.; Bath, K.-L.; Tsamis, V.; Tigani, K.; Farmakopoulos, A.; Douvris, A.; Liakos, A.; Eberle, A.; Farago, O.

    2013-08-01

    Aims: Occultations of bright stars by planets provide information on the state of their atmospheres. An occultation of the bright star 45 Capricornii (HIP 107302) by Jupiter occurred on the night of 3/4 August 2009. Methods: The event was observed at multiple sites in Europe, Africa and South America and with instruments ranging in aperture from 0.4 m to 2.2 m. All observations, except one, were carried out in methane absorption bands centred at 0.89 μm and 2.2 μm to minimise the planetary contribution to the measured stellar flux. Following the application of special post-processing techniques, differential photometry was performed. Nearby bright satellites were used as reference sources. Results: Fifteen lightcurves were obtained. The photometric time series for fourteen of these were fitted to a model atmosphere of constant scale height (H). Estimates of H for most lightcurves lie within the range 20-30 km with an inverse-variance weighted mean of 23.6 ± 0.4 km, in good agreement with previous works. A comparison between half-light times at ingress and at egress implies an astrometric offset of 10-15 mas in Jupiter's position relative to the star. Five lightcurves - two for ingress and three for egress - were numerically inverted into profiles of pressure versus temperature. Isothermal, mutually consistent behaviour is observed within the pressure range 3-10 μbar. The inferred temperature of 165 ± 5 K is consistent with, but slightly higher than, that measured by the Galileo Probe at 5° S latitude in 1995 at the same pressure level. Subtraction of isothermal models for nine cases show the presence of at least one, and possibly two, non-isothermal layers a few tens of km below the half-light datum. Their altitudes are similar to those of features previously reported during the occultation of HIP 9369 in 1999. Our temperature estimates are consistent with the expected small magnitude of the perturbation of the atmosphere following the impact event on Jupiter

  7. JUPITER and satellites: Clinical implications of the JUPITER study and its secondary analyses.

    PubMed

    Kostapanos, Michael S; Elisaf, Moses S

    2011-07-26

    THE JUSTIFICATION FOR THE USE OF STATINS IN PREVENTION: an intervention trial evaluating rosuvastatin (JUPITER) study was a real breakthrough in primary cardiovascular disease prevention with statins, since it was conducted in apparently healthy individuals with normal levels of low-density lipoprotein cholesterol (LDL-C < 130 mg/dL) and increased inflammatory state, reflected by a high concentration of high-sensitivity C-reactive protein (hs-CRP ≥ 2 mg/L). These individuals would not have qualified for statin treatment according to current treatment guidelines. In JUPITER, rosuvastatin was associated with significant reductions in cardiovascular outcomes as well as in overall mortality compared with placebo. In this paper the most important secondary analyses of the JUPITER trial are discussed, by focusing on their novel findings regarding the role of statins in primary prevention. Also, the characteristics of otherwise healthy normocholesterolemic subjects who are anticipated to benefit more from statin treatment in the clinical setting are discussed. Subjects at "intermediate" or "high" 10-year risk according to the Framingham score, those who exhibit low post-treatment levels of both LDL-C (< 70 mg/dL) and hs-CRP (< 1 mg/L), who are 70 years of age or older, as well as those with moderate chronic kidney disease (estimated glomerular filtration rate < 60 mL/min every 1.73 m(2)) are anticipated to benefit more from statin treatment. Unlikely other statin primary prevention trials, JUPITER added to our knowledge that statins may be effective drugs in the primary prevention of cardiovascular disease in normocholesterolemic individuals at moderate-to-high risk. Also, statin treatment may reduce the risk of venous thromboembolism and preserve renal function. An increase in physician-reported diabetes represents a major safety concern associated with the use of the most potent statins.

  8. Explaining embodied cognition results.

    PubMed

    Lakoff, George

    2012-10-01

    From the late 1950s until 1975, cognition was understood mainly as disembodied symbol manipulation in cognitive psychology, linguistics, artificial intelligence, and the nascent field of Cognitive Science. The idea of embodied cognition entered the field of Cognitive Linguistics at its beginning in 1975. Since then, cognitive linguists, working with neuroscientists, computer scientists, and experimental psychologists, have been developing a neural theory of thought and language (NTTL). Central to NTTL are the following ideas: (a) we think with our brains, that is, thought is physical and is carried out by functional neural circuitry; (b) what makes thought meaningful are the ways those neural circuits are connected to the body and characterize embodied experience; (c) so-called abstract ideas are embodied in this way as well, as is language. Experimental results in embodied cognition are seen not only as confirming NTTL but also explained via NTTL, mostly via the neural theory of conceptual metaphor. Left behind more than three decades ago is the old idea that cognition uses the abstract manipulation of disembodied symbols that are meaningless in themselves but that somehow constitute internal "representations of external reality" without serious mediation by the body and brain. This article uniquely explains the connections between embodied cognition results since that time and results from cognitive linguistics, experimental psychology, computational modeling, and neuroscience.

  9. The observational case for Jupiter being a typical massive planet.

    PubMed

    Lineweaver, Charles H; Grether, Daniel

    2002-01-01

    We identify a subsample of the recently detected extrasolar planets that is minimally affected by the selection effects of the Doppler detection method. With a simple analysis we quantify trends in the surface density of this subsample in the period-Msin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus indicating that Jupiter is a typical massive planet rather than an outlier. Our analysis suggests that Jupiter is more typical than indicated by previous analyses. For example, instead of MJup mass exoplanets being twice as common as 2 MJup exoplanets, we find they are three times as common.

  10. The Jupiter system through the eyes of Voyager 1

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.A.; Johnson, T.V.; Ingersoll, A.P.; Collins, S.A.; Shoemaker, E.M.; Hunt, G.E.; Masursky, H.; Carr, M.H.; Davies, M.E.; Cook, A.F.; Boyce, J.; Danielson, G.E.; Owen, editors, Timothy W.; Sagan, C.; Beebe, R.F.; Veverka, J.; Strom, R.G.; McCauley, J.F.; Morrison, D.; Briggs, G.A.; Suomi, V.E.

    1979-01-01

    The cameras aboard Voyager I have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. Copyright ?? 1979 AAAS.

  11. Return to Europa: Overview of the Jupiter Europa Orbiter Mission

    NASA Technical Reports Server (NTRS)

    Clark, K.; Tan-Wang, G.; Boldt, J.; Greeley, R.; Jun, I.; Lock, R.; Ludwinski, J.; Pappalardo, R.; Van Houten, T.; Yan, T.

    2009-01-01

    Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, Galileo supplied fascinating new insights into that satellite's secrets. The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the Europa Jupiter System Mission (EJSM), an international mission with orbiters developed by NASA, ESA and possibly JAXA. JEO would address a very important subset of the complete EJSM science objectives and is designed to function alone or in conjunction with ESA's Jupiter Ganymede Orbiter (JGO).

  12. The jupiter system through the eyes of voyager 1.

    PubMed

    Smith, B A; Soderblom, L A; Johnson, T V; Ingersoll, A P; Collins, S A; Shoemaker, E M; Hunt, G E; Masursky, H; Carr, M H; Davies, M E; Cook, A F; Boyce, J; Danielson, G E; Owen, T; Sagan, C; Beebe, R F; Veverka, J; Strom, R G; McCauley, J F; Morrison, D; Briggs, G A; Suomi, V E

    1979-06-01

    The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. PMID:17800430

  13. The Jupiter-Io connection - An Alfven engine in space

    NASA Technical Reports Server (NTRS)

    Belcher, John W.

    1987-01-01

    Much has been learned about the electromagnetic interaction between Jupiter and its satellite Io from in situ observations. Io, in its motion through the Io plasma torus at Jupiter, continuously generates an Alfven wing that carries two billion kilowatts of power into the jovian ionosphere. Concurrently, Io is acted upon by a J x B force tending to propel it out of the jovian system. The energy source for these processes is the rotation of Jupiter. This unusual planet-satellite coupling serves as an archetype for the interaction of a large moving conductor with a magnetized plasma, a problem of general space and astrophysical interest.

  14. The Jupiter-Io connection - an Alfven engine in space

    NASA Astrophysics Data System (ADS)

    Belcher, J. W.

    1987-10-01

    Much has been learned about the electromagnetic interaction between Jupiter and its satellite Io from in situ observations. Io, in its motion through the Io plasma torus at Jupiter, continuously generates an Alfven wing that carries two billion kilowatts of power into the jovian ionosphere. Concurrently, Io is acted upon by a J x B force tending to propel it out of the jovian system. The energy source for these processes is the rotation of Jupiter. This unusual planet-satellite coupling serves as an archetype for the interaction of a large moving conductor with a magnetized plasma, a problem of general space and astrophysical interest.

  15. The jupiter system through the eyes of voyager 1.

    PubMed

    Smith, B A; Soderblom, L A; Johnson, T V; Ingersoll, A P; Collins, S A; Shoemaker, E M; Hunt, G E; Masursky, H; Carr, M H; Davies, M E; Cook, A F; Boyce, J; Danielson, G E; Owen, T; Sagan, C; Beebe, R F; Veverka, J; Strom, R G; McCauley, J F; Morrison, D; Briggs, G A; Suomi, V E

    1979-06-01

    The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto.

  16. The Pioneer 11 imaging experiment of Jupiter

    NASA Technical Reports Server (NTRS)

    Swindell, W.; Fountain, J.

    1977-01-01

    Pioneer 11 flew by Jupiter in December 1974 and obtained several hundred images of the planet. It is presently targeted for encounter with Saturn in 1979. The imaging photopolarimeter recorded spin-scan images with high photometric accuracy. It also recorded polarimetric and zodiacal-light data. Careful design of the instrument resulted in excellent performance in the Jovian radiation environment. Imaging data were displayed to maintain the proper shape of the planet. Color images were made by synthesizing green data from red and blue data. Pictures created from Pioneer 11 imaging data show complex detail within the Red Spot is well as indications of flow around it. Bright spots with trailing plumes are seen in the Equatorial Zone. The North Polar Region is devoid of belt structure, but numerous irregular cells are seen in red light. The Galilean satellites were imaged with a resolution of several hundred kilometers.

  17. Auroral meridian scanning photometer calibration using Jupiter

    NASA Astrophysics Data System (ADS)

    Jackel, Brian J.; Unick, Craig; Creutzberg, Fokke; Baker, Greg; Davis, Eric; Donovan, Eric F.; Connors, Martin; Wilson, Cody; Little, Jarrett; Greffen, M.; McGuffin, Neil

    2016-10-01

    Observations of astronomical sources provide information that can significantly enhance the utility of auroral data for scientific studies. This report presents results obtained by using Jupiter for field cross calibration of four multispectral auroral meridian scanning photometers during the 2011-2015 Northern Hemisphere winters. Seasonal average optical field-of-view and local orientation estimates are obtained with uncertainties of 0.01 and 0.1°, respectively. Estimates of absolute sensitivity are repeatable to roughly 5 % from one month to the next, while the relative response between different wavelength channels is stable to better than 1 %. Astronomical field calibrations and darkroom calibration differences are on the order of 10 %. Atmospheric variability is the primary source of uncertainty; this may be reduced with complementary data from co-located instruments.

  18. Magnetic effects in hot Jupiter atmospheres

    SciTech Connect

    Rogers, T. M.; Komacek, T. D.

    2014-10-20

    We present magnetohydrodynamic simulations of the atmospheres of hot Jupiters ranging in temperature from 1100 to 1800 K. Magnetic effects are negligible in atmospheres with temperatures ≲1400 K. At higher temperatures winds are variable and, in many cases, mean equatorial flows can become westward, opposite to their hydrodynamic counterparts. Ohmic dissipation peaks at temperatures ∼1500-1600 K, depending on field strength, with maximum values ∼10{sup 18} W at 10 bars, substantially lower than previous estimates. Based on the limited parameter study done, this value cannot be increased substantially with increasing winds, higher temperatures, higher field strengths, different boundary conditions, or lower diffusivities. Although not resolved in these simulations, there is modest evidence that a magnetic buoyancy instability may proceed in hot atmospheres.

  19. Positional Catalogues of Saturn's and Jupiter's Moons

    NASA Astrophysics Data System (ADS)

    Yizhakevych, O.; Andruk, V.; Pakuliak, L.; Lukianchuk, V.; Shatokhina, S.

    In the framework of the UkrVO national project (http://ukr-vo.org/) we have started the processing of photographic observations of Saturn's (S1-S8) and Jupiter's (J6-J8) moons. Observations were conducted during 1961-1993 with three astrographs DLFA, DWA, DAZ and Z600 reflector. Plate images were digitized as tif-files with commercial scanners. Image processing was carried out by specific software package in the LINUX-MIDAS-ROMAFOT environment with Tycho2 as reference. The software was developed at the MAO NASU. Obtained positions of objects were compared with theoretically predicted ones in IMCCE (Paris) (www.imcce.fr/sat) online. Rms error of divergence between observed and calculated positions is of 0.20' - 0.35'.

  20. A model of Jupiter's sulfur nebula

    NASA Technical Reports Server (NTRS)

    Brown, R. A.

    1976-01-01

    A simple model of Jupiter's S II emission nebula is developed on the basis of a complete treatment of electron-impact excitation of sulfur ions. Forbidden line emission from S II ions excited by electron collisions in the Jovian nebula is analyzed, and existing observations are interpreted using a simple model of an S II nebula which is uniform in depth. The results show that the depth of the nebula is 300,000 to 600,000 km, the electron density is about 3160 per cu cm, the electron temperature is approximately 25,000 K, and the S II concentration is roughly 79 ions per cu cm. It is noted that these plasma conditions are quite different from those reported for the same region on the basis of Pioneer 10 data, indicating that the S II nebula is a sporadic event. Io is suggested as the source of the sulfur.

  1. Movie of High Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter's high-altitude clouds are seen in this brief movie made from seven frames taken by the narrow-angle camera of NASA's Cassini spacecraft. This is the first time a movie sequence of Jupiter has been made that illustrates the motions of the high-altitude clouds on a global scale.

    The images were taken at a wavelength that is absorbed by methane, one chemical in Jupiter's lower clouds. So, dark areas are relatively free of high clouds, and the camera sees through to the methane in a lower level. Bright areas are places with high, thick clouds that shield the methane below.

    Jupiter's equator and Great Red Spot are covered with high-altitude, hazy clouds.

    The movie covers the time period between Oct. 1 and Oct. 5, 2000, latitudes from 50 degrees north to 50 degrees south, and a 100-degree sweep of longitude. Those factors were the same for a Cassini movie of cloud motions previously released (PIA02829), but that movie used frames taken through a blue filter, which showed deeper cloud levels and sharper detail. Features in this methane-filter movie appear more diffuse.

    Among the nearly stationary features are the Red Spot and some bright ovals at mid-latitudes in both hemispheres. These are anticyclonic (counter-clockwise rotating) storms. They are bright in the methane band because of their high clouds associated with rising gas. They behave differently from terrestrial cyclones, which swirl in the opposite direction. The mechanism making the Red Spot and similar spots stable apparently has no similarity to the mechanism which feeds terrestrial cyclones.

    Some small-scale features are fascinating because of their brightness fluctuations. Such fluctuations observed in the methane band are probably caused by strong vertical motions, which form clouds rapidly, as in Earth's thunderstorms. Near the upper left corner in this movie, a number of smaller clouds appear to circulate counterclockwise around a dark spot, and these clouds fluctuate in

  2. Charged particle distributions in Jupiter's magnetosphere

    NASA Astrophysics Data System (ADS)

    Divine, N.; Garrett, H. B.

    1983-09-01

    In situ data from the Pioneer and Voyager spacecraft, supplemented by earth-based observations and theoretical considerations, are used as the basis for the present quantitative, compact model of the 1 eV-several MeV charged particle distribution in the Jovian magnetosphere. The thermal plasma parameters of convection speed, number density, and characteristic energy, are specified as functions of position for electrons and for the ion species H(+), O(+), O(2+), S(+), S(2+), S(3+), and Na(+). Major features of the magnetic field, thermal plasma, and trapped particle distributions, are modeled and results for each plasma region are compared with observed spectra. Comparisons show that the model represents the data to within a factor of 2 + or - 1, except where time variations are significant. Practical applications of the model to spacecraft near Jupiter are given.

  3. Magnetospheric ray tracing studies. [Jupiter's decametric radiation

    NASA Technical Reports Server (NTRS)

    Six, N. F.

    1982-01-01

    Using a model of Jupiter's magnetized plasma environment, radiation raypaths were calculated with a three-dimension ray tracing program. It is assumed that energetic particles produce the emission in the planet's auroral zone at frequencies just above the electron gyrofrequencies. This radiation is generated in narrow sheets defined by the angle of a ray with respect to the magnetic field line. By specifying the source position: latitude, longitude, and radial distance from the planet, signatures in the spectrum of frequency versus time seen by Voyager 1 and 2 were duplicated. The frequency range and the curvature of the decametric arcs in these dynamic spectra are the result of the geometry of the radiation sheets (imposed by the plasma and by the B-field) and illumination of Voyager 1 and 2 as the rotating magnetosphere mimics a pulsar.

  4. Ray tracing studies of Jupiter's magnetosphere

    NASA Technical Reports Server (NTRS)

    Six, N. F.

    1982-01-01

    Raypaths for decametric wavelength radiation in Jupiter's magnetosphere were calculated. The model-dependent raypaths with the Voyager observations were compared. Characteristics of the source regions and the influence of propagation effects were deduced. A three dimensional ray tracing program was employed to calculate the raypaths. Families of rays were launched at particular angles with respect to the magnetic field lines to generate conical sheets of radiation for various frequencies and various source locations. As the planet's magnetic field rotates, these warped sheets of radiation sweep past the observer, producing signatures in frequency versus time plots. These signatures match some of those found in the Voyager data. The greatest propagation effects occur in and around the source regions in the Io auroral oval.

  5. From Tunguska to Chelyabinsk via Jupiter

    NASA Astrophysics Data System (ADS)

    Artemieva, Natalia A.; Shuvalov, Valery V.

    2016-06-01

    The Tunguska event remained enigmatic for almost 100 years until the collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 helped to resolve this enigma and allowed us to adequately interpret the more recent Chelyabinsk event. Airbursts typically occur if a meteoroid entering Earth's atmosphere is 10-100 m in diameter, i.e., its energy ranges from 0.5 (Chelyabinsk) to 20 (Tunguska) Mt TNT. All this energy is released in the atmosphere with strong shock waves generated during the entry reaching the surface and causing substantial damage. Atmospheric plumes are capable of dispersing extraterrestrial materials worldwide. Modern civilization is extremely vulnerable to those relatively small disturbances that recur on a decadal timescale and are still difficult to predict.

  6. Jupiter: Aerosol Chemistry in the Polar Atmosphere.

    PubMed

    Wong; Lee; Yung; Ajello

    2000-05-10

    Aromatic compounds have been considered a likely candidate for enhanced aerosol formation in the polar region of Jupiter. We develop a new chemical model for aromatic compounds in the Jovian auroral thermosphere/ionosphere. The model is based on a previous model for hydrocarbon chemistry in the Jovian atmosphere and is constrained by observations from Voyager, Galileo, and the Infrared Space Observatory. Precipitation of energetic electrons provides the major energy source for the production of benzene and other heavier aromatic hydrocarbons. The maximum mixing ratio of benzene in the polar model is 2x10-9, a value that can be compared with the observed value of 2+2-1x10-9 in the north polar auroral region. Sufficient quantities of the higher ring species are produced so that their saturated vapor pressures are exceeded. Condensation of these molecules is expected to lead to aerosol formation. PMID:10813686

  7. Jupiter analogues and planets of active stars

    NASA Astrophysics Data System (ADS)

    Kürster, M.; Zechmeister, M.; Endl, M.; Lo Curto, G.; Hartman, H.; Nilsson, H.; Henning, T.; Hatzes, A. P.; Cochran, W. D.

    2013-04-01

    Combined results are now available from a 15 year long search for Jupiter analogues around solar-type stars using the ESO CAT + CES, ESO 3.6 m + CES, and ESO 3.6 m + HARPS instruments. They comprise planet (co-)discoveries (ι Hor and HR 506) and confirmations (three planets in HR 3259) as well as non-confirmations of planets (HR 4523 and ɛ Eri) announced elsewhere. A long-term trend in ɛ Ind found by our survey is probably attributable to a Jovian planet with a period >30 yr, but we cannot fully exclude stellar activity effects as the cause. A 3.8 year periodic variation in HR 8323 can be attributed to stellar activity.

  8. Rotational Properties of Jupiter Trojan 1173 Anchises

    NASA Astrophysics Data System (ADS)

    Chatelain, Joseph; Henry, Todd; French, Linda; Trilling, David

    2015-11-01

    Anchises (1173) is a large Trojan asteroid librating about Jupiter’s L5 Lagrange point. Here we examine its rotational and lightcurve properties by way of data collected over a 3.5 year observing campaign. The length of the campaign means that data were gathered for more than a quarter of Anchises' full orbital revolution which allows for accurate determinations of pole orientation and bulk shape properties for the asteroid that can then be compared to results of previous work (i.e. French 1987, Horner et al. 2012). In addition to light curves, photometric data taken during this campaign could potentially detect color differences between hemispheres as the viewing geometry changes over time. Understanding these details about a prominent member of the Jupiter Trojans may help us better understand the history of this fascinating and important group of asteroids.

  9. From Tunguska to Chelyabinsk via Jupiter

    NASA Astrophysics Data System (ADS)

    Artemieva, Natalia A.; Shuvalov, Valery V.

    2016-06-01

    The Tunguska event remained enigmatic for almost 100 years until the collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 helped to resolve this enigma and allowed us to adequately interpret the more recent Chelyabinsk event. Airbursts typically occur if a meteoroid entering Earth's atmosphere is 10–100 m in diameter, i.e., its energy ranges from 0.5 (Chelyabinsk) to 20 (Tunguska) Mt TNT. All this energy is released in the atmosphere with strong shock waves generated during the entry reaching the surface and causing substantial damage. Atmospheric plumes are capable of dispersing extraterrestrial materials worldwide. Modern civilization is extremely vulnerable to those relatively small disturbances that recur on a decadal timescale and are still difficult to predict.

  10. Relativistic electrons and whistlers in Jupiter's magnetosphere

    NASA Technical Reports Server (NTRS)

    Barbosa, D. D.; Coroniti, F. V.

    1976-01-01

    The path-integrated gain of parallel propagating whistlers driven unstable by an anisotropic distribution of relativistic electrons in the stable trapping region of Jupiter's inner magnetosphere was computed. The requirement that a gain of 3 e-foldings of power balance the power lost by imperfect reflection along the flux tube sets a stably-trapped flux of electrons which is close to the non-relativistic result. Comparison with measurements shows that observed fluxes are near the stably-trapped limit, which suggests that whistler wave intensities may be high enough to cause significant diffusion of electrons accounting for the observed reduction of phase space densities. A crude estimate of the wave intensity necessary to diffuse electrons on a radial diffusion time scale yields a lower limit for the magnetic field fluctuation intensity.

  11. Does Io's ionosphere influence Jupiter's radio bursts.

    NASA Technical Reports Server (NTRS)

    Webster, D. L.; Alksne, A. Y.; Whitten, R. C.

    1972-01-01

    Goldreich and Lynden-Bell's theory of Jupiter's Io-correlated decametric radiation sets a lower limit to Io's conductivity, high enough to carry the current associated with the radiated power. Dermott's analysis of conductivities of rocks and ice shows no such conductivity at Io's temperature. However, we show that if Io has even a small atmosphere, say of methane as suggested by Binder and Cruikshank, or of argon or nitrogen, it will have an ionosphere with adequate conductivity to meet the above criterion. A requirement for higher conductivity was found by Goldreich and Lynden-Bell on the basis of motion of magnetic lines past Io. This requirement appears to us unnecessary in view of experiments which prove that motion of the lines is not the source of the electromotance.

  12. Moons over Jupiter: transits and shadow transits

    NASA Astrophysics Data System (ADS)

    Rogers, J. H.; et al.

    2003-06-01

    There is no more beautiful illustration of orbital motions than the movements of Jupiter's satellites. Every six years, their movements are most strikingly displayed, when the jovian system is presented edge-on to Earth. This means that there is a higher frequency of multiple transits over the face of the planet, as all the moons transit across the equatorial zone, whereas in other years Ganymede and Callisto transit near the poles or not at all. Also, for a few months, the satellites pass in front of each other, displaying mutual eclipses and occultations. In 2002/2003 we have been able to observe a fine series of these multiple and mutual events. On the cover, and on these pages, are some of the highest-resolution images received.

  13. Encouragement from Jupiter for Europe's Titan Probe

    NASA Astrophysics Data System (ADS)

    1996-04-01

    Huygens will transmit scientific information for 150 minutes, from the outer reaches of Titan's cold atmosphere and all the way down to its enigmatic surface. For comparison, the Jupiter Probe radioed scientific data for 58 minutes as it descended about 200 kilometres into the outer part of the atmosphere of the giant planet. The parachutes controlling various stages of Huygens' descent will rely upon a system for deployment designed and developed in Europe that is nevertheless similar to that used by the Jupiter Probe. The elaborate sequence of operations in Huygens worked perfectly during a dramatic drop test from a stratospheric balloon over Sweden in May 1995, which approximated as closely as possible to events on Titan. The performance of the American Probe at Jupiter renews the European engineers' confidence in their own descent control system, and also in the lithium sulphur-dioxide batteries which were chosen to power both Probes. "The systems work after long storage in space," comments Hamid Hassan, ESA's Project Manager for Huygens. "Huygens will spend seven years travelling to Saturn's vicinity aboard the Cassini Orbiter. The Jupiter Probe was a passenger in Galileo for six years before its release, so there is no reason to doubt that Huygens will work just as well." Huygens will enter the outer atmosphere of Titan at 20,000 kilometres per hour. A heat shield 2.7 metres in diameter will withstand the friction and slow the Probe to a speed at which parachutes can be deployed. The size of the parachute for the main phase of the descent is chosen to allow Huygens to reach the surface in about 2 hours. The batteries powering Huygens will last for about 21/2 hours. Prepared for surprises A different perspective on the Jupiter Probe comes from Jean-Pierre Lebreton, ESA's Project Scientist for Huygens. The results contradicted many preconceptions of the Galileo scientists, particularly about the abundance of water and the structure of cloud layers. Arguments

  14. Recent Hubble Observations of Jupiter's Ring System

    NASA Astrophysics Data System (ADS)

    Showalter, M. R.; Burns, J. A.; de Pater, I.; Hamilton, D. P.; Horanyi, M.

    2003-05-01

    The period December 2002 through February 2003 provided a rare opportunity to watch Jupiter sweep through its full range of Earth-based phase angles while the rings remained nearly edge-on to Earth. We used this period for a series of Jovian ring observations using the High Resolution Channel (HRC) of Hubble's new Advanced Camera for Surveys (ACS). Phase angles span 0.17o--10o. Our images showed the main ring, Adrastea and Metis with very high signal-to-noise ratios (SNR). Amalthea's gossamer ring was detected (and vertically resolved) in a small set of specially targeted images. Somewhat surprisingly, we have not yet been able to detect the halo in any of our images, perhaps because it is obscured by the scattered light from Jupiter's disk, positioned just 4'' outside the HRC's field of view. Preliminary results from this data set are as follows. (1) The ring is substantially less red than the moons, suggesting that fine dust represents a significant fraction of its backscattering intensity. (2) Neither the rings nor the embedded moons Metis and Adrastea have significant opposition surges. We were hoping to use the surge, which is characteristic of most macroscopic bodies but not dust, as an indicator of where any embedded ring parent bodies might reside. (3) Because our data are so sensitive to Metis (radius ˜ 20 km) and Adrastea ( ˜ 8 km), we believe that bodies as small as 3--4 km in radius should have been detected in the data. In an initial search, no additional bodies have been detected. (4) The Amalthea ring shows an enhancement in brightness in its outermost 15,000 km. This is consistent with what was seen in Galileo images at very high phase angles. Support for this work was provided by NASA through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.

  15. The European SL-9/JUPITER Workshop

    NASA Astrophysics Data System (ADS)

    1995-02-01

    During the past six months, many astronomers - observational as well theoretical - have been busy interpreting the many data taken during the impacts and thereafter. This is a very labour-intensive task and although the first conclusions have begun to emerge, it has also become obvious that extensive consultations between the various groups are necessary before it will be possible to understand the very complex processes during the impacts and thereafter. In order to further the interaction among the involved scientists, it has been decided to hold a three-day "European SL-9/Jupiter Workshop" at the Headquarters of the European Southern Observatory. More than 100 astronomers will meet on February 13-15, 1995, and close to 100 reports will be delivered on this occasion. Although most come from European countries, the major groups on other continents are also well represented. This meeting will give the participants the opportunity to exchange information about their individual programmes and will serve to establish future collaborative efforts. SL-9/JUPITER PRESS CONFERENCE In this connection, ESO is pleased to invite the media to a Press Conference: Wednesday, February 15, 1995, 17:30 CET ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany This conference will be held at the end of the Workshop and will provide a thorough overview of the latest results, as presented during the meeting. Media representatives who are interested in participating in this Press Conference are requested to register with the ESO Information Service (Mrs. E. Völk, Tel.: +49-89-32006276; Fax: +49-89-3202362), at the latest on Friday, February 10, 1995. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE).

  16. Jets and Water Clouds on Jupiter

    NASA Astrophysics Data System (ADS)

    Lian, Yuan; Showman, A. P.

    2012-10-01

    Ground-based and spacecraft observations show that Jupiter exhibits multiple banded zonal jet structures. These banded jets correlate with dark and bright clouds, often called "belts" and "zones". The mechanisms that produce these banded zonal jets and clouds are poorly understood. Our previous studies showed that the latent heat released by condensation of water vapor could produce equatorial superrotation along with multiple zonal jets in the mid-to-high latitudes. However, that previous work assumed complete and instant removal of condensate and therefore could not predict the cloud formation. Here we present an improved 3D Jupiter model to investigate some effects of cloud microphysics on large-scale dynamics using a closed water cycle that includes condensation, three-dimensional advection of cloud material by the large-scale circulation, evaporation and sedimentation. We use a dry convective adjustment scheme to adjust the temperature towards a dry adiabat when atmospheric columns become convectively unstable, and the tracers are mixed within the unstable layers accordingly. Other physics parameterizations included in our model are the bottom drag and internal heat flux as well as the choices of either Newtonian heating scheme or gray radiative transfer. Given the poorly understood cloud microphysics, we perform case studies by treating the particle size and condensation/evaporation time scale as free parameters. We find that, in some cases, the active water cycle can produce multiple banded jets and clouds. However, the equatorial jet is generally very weak in all the cases because of insufficient supply of eastward eddy momentum fluxes. These differences may result from differences in the overall vertical stratification, baroclinicity, and moisture distribution in our new models relative to the older ones; we expect to elucidate the dynamical mechanisms in continuing work.

  17. Multiple planets or exomoons in Kepler hot Jupiter systems with transit timing variations?

    NASA Astrophysics Data System (ADS)

    Szabó, R.; Szabó, Gy. M.; Dálya, G.; Simon, A. E.; Hodosán, G.; Kiss, L. L.

    2013-05-01

    Aims: Hot Jupiters are thought to belong to single-planet systems. Somewhat surprisingly, some hot Jupiters have been reported to exhibit transit timing variations (TTVs). The aim of this paper is to identify the origin of these observations, identify possible periodic biases leading to false TTV detections, and refine the sample to a few candidates with likely dynamical TTVs. Methods: We present TTV frequencies and amplitudes of hot Jupiters in Kepler Q0-6 data with Fourier analysis and a frequency-dependent bootstrap calculation to assess the false alarm probability levels of the detections. Results: We identified 36 systems with TTV above four standard deviation confidence, about half of them exhibiting multiple TTV frequencies. Fifteen of these objects (HAT-P-7b, KOI-13, 127, 183, 188, 190, 196, 225, 254, 428, 607, 609, 684, 774, 1176) probably show TTVs due to a systematic observational effect: long cadence data sampling is regularly shifted transit-by-transit, interacting with the transit light curves, introducing a periodic bias, and leading to a stroboscopic period. For other systems, the activity and rotation of the host star can modulate light curves and explain the observed TTVs. By excluding the systems that were inadequately sampled, showed TTV periods related to the stellar rotation, or turned out to be false positives or suspects, we ended up with seven systems. Three of them (KOI-186, 897, 977) show the weakest stellar rotation features, and these are our best candidates for dynamically induced TTV variations. Conclusions: Those systems with periodic TTVs that we cannot explain with systematics from observation, stellar rotation, activity, or inadequate sampling, may be multiple systems or even exomoon hosts. Appendix A is available in electronic form at http://www.aanda.org

  18. Explaining wartime rape.

    PubMed

    Gottschall, Jonathan

    2004-05-01

    In the years since the first reports of mass rapes in the Yugoslavian wars of secession and the genocidal massacres in Rwanda, feminist activists and scholars, human rights organizations, journalists, and social scientists have dedicated unprecedented efforts to document, explain, and seek solutions for the phenomenon of wartime rape. While contributors to this literature agree on much, there is no consensus on causal factors. This paper provides a brief overview of the literature on wartime rape in historical and ethnographical societies and a critical analysis of the four leading explanations for its root causes: the feminist theory, the cultural pathology theory, the strategic rape theory, and the biosocial theory. The paper concludes that the biosocial theory is the only one capable of bringing all the phenomena associated with wartime rape into a single explanatory context.

  19. Explaining immigrant naturalization.

    PubMed

    Yang, P Q

    1994-01-01

    "Prior research on immigrant naturalization has focused mainly on the effects of immigrants' adaptation experiences and demographic characteristics on their propensity to naturalize. This article proposes a broader analytical framework which incorporates immigrants' individual characteristics and larger social contexts in the country of origin and the country of destination to explain the likelihood of citizenship acquisition. The framework is tested for a cohort of recent immigrants, using the PUMS data from the 1980 U.S. census. The results show that economic, political, social, cultural and geographical conditions in the country of origin, and immigrants ethnic communities and urban concentration in the country of destination, to a large extent influence immigrants' propensity for naturalization and that, net of the contextual factors, many of the immigrants' adaptation and demographic characteristics are also significant predictors of citizenship acquisition."

  20. Explaining moral religions.

    PubMed

    Baumard, Nicolas; Boyer, Pascal

    2013-06-01

    Moralizing religions, unlike religions with morally indifferent gods or spirits, appeared only recently in some (but not all) large-scale human societies. A crucial feature of these new religions is their emphasis on proportionality (between deeds and supernatural rewards, between sins and penance, and in the formulation of the Golden Rule, according to which one should treat others as one would like others to treat oneself). Cognitive science models that account for many properties of religion can be extended to these religions. Recent models of evolved dispositions for fairness in cooperation suggest that proportionality-based morality is highly intuitive to human beings. The cultural success of moralizing movements, secular or religious, could be explained based on proportionality.

  1. Explaining moral religions.

    PubMed

    Baumard, Nicolas; Boyer, Pascal

    2013-06-01

    Moralizing religions, unlike religions with morally indifferent gods or spirits, appeared only recently in some (but not all) large-scale human societies. A crucial feature of these new religions is their emphasis on proportionality (between deeds and supernatural rewards, between sins and penance, and in the formulation of the Golden Rule, according to which one should treat others as one would like others to treat oneself). Cognitive science models that account for many properties of religion can be extended to these religions. Recent models of evolved dispositions for fairness in cooperation suggest that proportionality-based morality is highly intuitive to human beings. The cultural success of moralizing movements, secular or religious, could be explained based on proportionality. PMID:23664451

  2. TIDAL AND MAGNETIC INTERACTIONS BETWEEN A HOT JUPITER AND ITS HOST STAR IN THE MAGNETOSPHERIC CAVITY OF A PROTOPLANETARY DISK

    SciTech Connect

    Chang, S.-H.; Gu, P.-G.; Bodenheimer, P. H.

    2010-01-10

    We present a simplified model to study the orbital evolution of a young hot Jupiter inside the magnetospheric cavity of a proto-planetary disk. The model takes into account the disk locking of stellar spin as well as the tidal and magnetic interactions between the star and the planet. We focus on the orbital evolution starting from the orbit in 2:1 resonance with the inner edge of the disk, followed by the inward and then outward orbital migration driven by the tidal and magnetic torques as well as the Roche-lobe overflow of the tidally inflated planet. The goal in this paper is to study how the orbital evolution inside the magnetospheric cavity depends on the cavity size, planet mass, and orbital eccentricity. In the present work, we only target the mass range from 0.7 to 2 Jupiter masses. In the case of the large cavity corresponding to the rotational period approx7 days, the planet of mass >1 Jupiter mass with moderate initial eccentricities (approx>0.3) can move to the region <0.03 AU from its central star in 10{sup 7} yr, while the planet of mass <1 Jupiter mass cannot. We estimate the critical eccentricity beyond which the planet of a given mass will overflow its Roche radius and finally lose all of its gas onto the star due to runaway mass loss. In the case of the small cavity corresponding to the rotational period approx3 days, all of the simulated planets lose all of their gas even in circular orbits. Our results for the orbital evolution of young hot Jupiters may have the potential to explain the absence of low-mass giant planets inside approx0.03 AU from their dwarf stars revealed by transit surveys.

  3. Extreme ultraviolet observations from voyager 1 encounter with jupiter.

    PubMed

    Broadfoot, A L; Belton, M J; Takacs, P Z; Sandel, B R; Shemansky, D E; Holberg, J B; Ajello, J M; Atreya, S K; Donahue, T M; Moos, H W; Bertaux, J L; Blamont, J E; Strobel, D F; McConnell, J C; Dalgarno, A; Goody, R; McElroy, M B

    1979-06-01

    Observations of the optical extreme ultraviolet spectrum of the Jupiter planetary system during the Voyager 1 encounter have revealed previously undetected physical processes of significant proportions. Bright emission lines of S III, S IV, and O III indicating an electron temperature of 10(5) K have been identified in preliminary analyses of the Io plasma torus spectrum. Strong auroral atomic and molecular hydrogen emissions have been observed in the polar regions of Jupiter near magnetic field lines that map the torus into the atmosphere of Jupiter. The observed resonance scattering of solar hydrogen Lyman alpha by the atmosphere of Jupiter and the solar occultation experiment suggest a hot thermosphere (>/= 1000 K) wvith a large atomic hydrogen abundance. A stellar occultation by Ganymede indicates that its atmosphere is at most an exosphere.

  4. GENERAL VIEW OF SITE LOOKING SOUTHWEST. JUPITER 'HOP' STAND, FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL VIEW OF SITE LOOKING SOUTHWEST. JUPITER 'HOP' STAND, FOREGROUND CENTER, REDSTONE TEST STAND FOREGROUND RIGHT, SATURN I C TEST STAND BACKGROUND LEFT. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  5. JUPITER PROJECT - JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY

    EPA Science Inventory

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project builds on the technology of two widely used codes for sensitivity analysis, data assessment, calibration, and uncertainty analysis of environmental models: PEST and UCODE.

  6. Metallization and electrical conductivity of hydrogen in Jupiter.

    PubMed

    Nellis, W J; Weir, S T; Mitchell, A C

    1996-08-16

    Electrical conductivities of molecular hydrogen in Jupiter were calculated by scaling electrical conductivities measured at shock pressures in the range of 10 to 180 gigapascals (0.1 to 1.8 megabars) and temperatures to 4000 kelvin, representative of conditions inside Jupiter. Jupiter's magnetic field is caused by convective dynamo motion of electrically conducting fluid hydrogen. The data imply that Jupiter should become metallic at 140 gigapascals in the fluid, and the electrical conductivity in the jovian molecular envelope at pressures up to metallization is about an order of magnitude larger than expected previously. The large magnetic field is produced in the molecular envelope closer to the surface than previously thought. PMID:8688072

  7. Fitting Orbits to Jupiter's Moons with a Spreadsheet.

    ERIC Educational Resources Information Center

    Bridges, Richard

    1995-01-01

    Describes how a spreadsheet is used to fit a circular orbit model to observations of Jupiter's moons made with a small telescope. Kepler's Third Law and the inverse square law of gravity are observed. (AIM)

  8. Jupiter Magnetospheric Orbiter and Trojan Asteroid Explorer in EJSM

    NASA Astrophysics Data System (ADS)

    Sasaki, Sho; Fujimoto, Masaki; Yano, Hajime; Takashima, Takeshi; Kasaba, Yasumasa; Funase, Ryu; Tsuda, Yuichi; Kawaguchi, Junichiro; Kawakatsu, Yasuhiro; Mori, Osamu; Morimoto, Mutsuko; Yoshida, Fumi; Takato, Naruhisa

    The international mission to explore the Jovian system is planned as Europa Jupiter System Mission (EJSM) aiming at the launch in 2020. EJSM consists of (1) the Jupiter Europa Orbiter (JEO) by NASA, (2) the Jupiter Ganymede Orbiter (JGO) by ESA, and (3) the Jupiter Magnetospheric Orbiter (JMO) studied by JAXA (Japan Aerospace Exploration Agency). In February 2009, NASA and ESA decided to continue the study of EJSM as a candidate of the outer solar system mission. In JAXA, a mission plan combining Trojan asteroid explorer with JMO started. According to the mission plan, as the main spacecraft flies by Jupiter, it will deploy the JMO satellite around Jupiter. Then the main will target one (or two) Trojan asteroids. JMO is a spin-stabilized satellite which will have magnetometers, low-energy plasma spectrome-ters, medium energy particle detectors, energetic particle detectors, electric field / plasma wave instruments, an ENA imager, an EUV spectrometer, and a dust detector. Collaborating with plasma instruments on board JEO and JGO, JMO will investigate the fast-rotating huge mag-netosphere to clarify the energy procurement from the rotation of Jupiter to the magnetosphere and to clarify the interaction between the solar wind and the magnetosphere. JAXA started the study of a solar power sail for deep space explorations. In addition to the function of a solar sail (photon propulsion), the solar power sail system has very efficient ion engines where electric power is produced solar panels within the sail. Currently we are studying a mission to Jupiter and Trojan asteroids using a large (100m-scale) solar power sail that can transfer large payload as far as Jupiter. Trojan asteroids, which orbit around Jupiter's Lagrangian points, are primitive bodies with information of the early solar system as well as raw solid materials of Jovian system. Proposed instruments for the Trojan spacecraft are cameras, IR spectrometers, XRS, a laser altimeter, and a small surface rover

  9. Ohmic Heating Suspends, Not Reverses, the Cooling Contraction of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Wu, Yanqin; Lithwick, Yoram

    2013-01-01

    We study the radius evolution of close-in extra-solar Jupiters under Ohmic heating, a mechanism that was recently proposed to explain the large observed sizes of many of these planets. Planets are born with high entropy and they subsequently cool and contract. We focus on two cases: first, that Ohmic heating commences when the planet is hot (high entropy); and second, that it commences after the planet has cooled. In the former case, we use analytical scaling and numerical experiments to confirm that Ohmic heating is capable of suspending the cooling as long as a few percent of the stellar irradiation is converted into Ohmic heating and the planet has a surface wind that extends to pressures of ~10 bar or deeper. For these parameters, the radii at which cooling is stalled are consistent with (or larger than) the observed radii of most planets. The only two exceptions are WASP-17b and HAT-P-32b. In contrast to the high entropy case, we show that Ohmic heating cannot significantly re-inflate planets after they have already cooled. This leads us to suggest that the diversity of radii observed in hot Jupiters may be partially explained by the different epochs at which they are migrated to their current locations.

  10. Is Jupiter's magnetosphere like a pulsar's or earth's?

    NASA Technical Reports Server (NTRS)

    Kennel, C. F.; Coroniti, F. V.

    1974-01-01

    The application of pulsar physics to determine the magnetic structure in the planet Jupiter outer magnetosphere is discussed. A variety of theoretical models are developed to illuminate broad areas of consistency and conflict between theory and experiment. Two possible models of Jupiter's magnetosphere, a pulsar-like radial outflow model and an earth-like convection model, are examined. A compilation of the simple order of magnitude estimates derivable from the various models is provided.

  11. Ulysses operations at Jupiter - Planning for the unknown

    NASA Technical Reports Server (NTRS)

    Angold, N.; Beech, P.; Garcia-Perez, R.; Mcgarry, A.; Standley, S.

    1992-01-01

    The operational preparations for the Ulysses encounter with Jupiter are described with particular attention given to requirements for survival in the Jovian environment, ground-segment planning, a deep-space network, and encounter activities. It is concluded that the successful operation of the Ulysses spacecraft at Jupiter was the culmination of many years of activity, from spacecraft design and mission planning to the coordination of the encounter activities and production of the detailed timeline.

  12. The origin of external oxygen in Jupiter and Saturn's environments

    NASA Astrophysics Data System (ADS)

    Cavalié, T.; Lellouch, E.; Hartogh, P.; Moreno, R.; Billebaud, F.; Bockelée-Morvan, D.; Biver, N.; Cassidy, T.; Courtin, R.; Crovisier, J.; Dobrijevic, M.; Feuchtgruber, H.; González, A.; Greathouse, T.; Jarchow, C.; Kidger, M.; Lara, L. M.; Rengel, M.; Orton, G.; Sagawa, H.; de Val-Borro, M.

    2014-12-01

    This paper reviews the recent findings of the Herschel Solar System Observations Key Program (Hartogh et al. 2009), as well as ground-based supporting observations, regarding the origin of external oxygen in the environments of Jupiter and Saturn. Herschel-HIFI and PACS observations have been used to shown that the Shoemaker-Levy 9 comet is the source of Jupiter's stratospheric water, and that Enceladus (and its geysers) are most probably the source of water for Saturn and Titan.

  13. A Look Inside the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Grammier, Richard S.

    2008-01-01

    Juno, the second mission within the New Frontiers Program, is a Jupiter polar orbiter mission designed to return high-priority science data that spans across multiple divisions within NASA's Science Mission Directorate. Juno's science objectives, coupled with the natural constraints of a cost-capped, PI-led mission and the harsh environment of Jupiter, have led to a very unique mission and spacecraft design.

  14. Photochemistry and clouds of Jupiter, Saturn and Uranus

    NASA Technical Reports Server (NTRS)

    Atreya, S. K.; Romani, P. N.

    1985-01-01

    Photochemistry of ammonia, methane, phosphine, hydrogen sulfide, methylamine, hydrogen cyanide and carbon monoxide in the atmospheres of Jupiter, Saturn and Uranus is discussed. Condensation of ammonia, ammonium hydrosulfide, water, methane, ethane and acetylene below and near the tropopause of these planets is formulated. Whenever necessary, new calculations are included. Candidates for the upper atmospheric hazes, and the reddish-brown chromosphore in the clouds of Jupiter and Saturn are discussed.

  15. Shoemaker-Levy 9/JUPITER Collision Update

    NASA Astrophysics Data System (ADS)

    1994-05-01

    There are many signs that the upcoming collision between comet Shoemaker-Levy 9 and giant planet Jupiter is beginning to catch the imagination of the public. Numerous reports in the various media describe the effects expected during this unique event which according to the latest calculations will start in the evening of July 16 and end in the morning of July 22, 1994. (The times in this Press Release are given in Central European Summer Time (CEST), i.e., Universal Time (UT) + 2 hours. The corresponding local time in Chile is CEST - 6 hours.) Astronomers all over the world are now preparing to observe the associated phenomena with virtually all major telescopes. There will be no less than 12 different investigations at the ESO La Silla observatory during this period. This Press Release updates the information published in ESO PR 02/94 (27 January 1994) and provides details about the special services which will be provided by ESO to the media around this rare astronomical event. SCIENTIFIC EXPECTATIONS The nucleus of comet Shoemaker-Levy 9 broke into many smaller pieces during a near passage of Jupiter in July 1992. They are now moving in parallel orbits around this planet and recent calculations show with close to 100 % certainty that they will all collide with it, just two months from now. At some time, more than 20 individual nuclei were observed. This Press Release is accompanied by a photo that shows this formation, the famous "string of pearls", as it looked like in early May 1994. Both Jupiter and these nuclei have been extensively observed during the past months. A large, coordinated observing programme at La Silla has been active since early April and the first results have become available. However, while we now possess more accurate information about the comet's motion and the times of impact, there is still great uncertainty about the effects which may actually be observed at the time of the impacts. This is first of all due to the fact that it has not

  16. FIRST EARTH-BASED DETECTION OF A SUPERBOLIDE ON JUPITER

    SciTech Connect

    Hueso, R.; Perez-Hoyos, S.; Sanchez-Lavega, A.; Wesley, A.; Go, C.; Wong, M. H.; De Pater, I.; Fletcher, L. N.; Boslough, M. B. E.; Orton, G. S.; Yanamandra-Fisher, P. A.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Clarke, J. T.; Noll, K. S.

    2010-10-01

    Cosmic collisions on planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths. The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light curve of the observations results in an estimated energy of the impact of (0.9-4.0) x 10{sup 15} J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g cm{sup -3}. Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  17. Jupiter's Polar Magnetosphere: Outstanding Issues to be Addressed By Juno

    NASA Astrophysics Data System (ADS)

    Kurth, W. S.; Connerney, J. E. P.; McComas, D. J.; Mauk, B.; Gladstone, R.; Adriani, A.; Bagenal, F.; Bolton, S. J.

    2014-12-01

    Juno is on course to enter polar orbit at Jupiter on July 4, 2016. After a small number of preliminary orbits during which the orbital period is reduced, approximately 30 science orbits will be executed to explore the interior of Jupiter, hence, its origin. A second primary objective of the mission, and the subject of this talk, is to carry out the first exploration of Jupiter's polar magnetosphere. All previous missions to Jupiter, including Ulysses, remained at low Jovian latitudes at close range, hence, our knowledge of Jupiter's polar magnetosphere is a composite of remote sensing (such as radio emissions in the hectometric and decametric bands as well as IR and UV images); application of observations of Earth's auroral and polar cap particles, fields, and auroral emissions; and modeling. While these likely inform our expectations of what Juno will actually measure qualitatively, Juno will provide the first in depth exploration of auroral processes at another planet, other than a small number of very brief encounters of Saturn's kilometric radio source region by Cassini. With a reasonably complete suite of in situ magnetospheric measurements coupled with remote sensing, Juno will enable us to compare Jupiter's polar magnetosphere with those expectations. Certainly, understanding the nature of auroral currents and mechanisms for particle acceleration are high on the list of priorities for these studies. In addition, it is expected that Juno will greatly improve our understanding of the mapping of auroral processes from high latitudes and low altitudes to the middle and outer magnetosphere.

  18. The Photoeccentric Effect and Proto-Hot-Jupiters

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, J. A.; Morton, T.; Murray-Clay, R. A.; Fabrycky, D. C.

    2012-05-01

    Hot Jupiters are an enigmatic class of planet, located so close to their host stars (< 0.1 AU) that they are unlikely to have formed in situ. Socrates et al. (2011) argued that the impulsive migration mechanisms proposed for situating these planets should produce an observable population of highly eccentric proto-hot-Jupiters that have not yet circularized, as well as moderately eccentric failed-hot-Jupiters, with periapses just beyond the influence of fast tidal circularization. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes follow-up by radial velocity, the only technique used to date to measure eccentricities. Here we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star’s density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations ---the ``photoeccentric effect'' ---even with long-cadence Kepler photometry and loosely-constrained stellar parameters. We measure the eccentricity of HD 17156 b from transit photometry and find it is good agreement with the value from radial-velocity measurements. We present initial results from our "distillation" of eccentric proto- and failed- hot-Jupiters from the Kepler sample. Supported by the National Science Foundation Graduate Research Fellowship under grant DGE-1144152

  19. First Earth-Based Detection of a Superbolide on Jupiter

    NASA Technical Reports Server (NTRS)

    Hueso, R.; Wesley, A.; Go, C.; Perez-Hoyos, S.; Wong, M. H.; Fletcher, L. N.; Sanchez-Lavega, A.; Boslough, M. B.; DePater, I.; Orton, G. S.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Hammel, H. B.; Clarke, J. T.; Noll, K. S.; Yanamandra-Fisher, P. A.

    2010-01-01

    Cosmic collisions can planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths, The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light carve of the observations results in an estimated energy of the impact of (0.9-4,0) x 10(exp 15) J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g/cu cm. Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination. of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  20. Galileo Update: The Search for Water in Jupiter's Atmosphere

    NASA Astrophysics Data System (ADS)

    1997-06-01

    This videotape presents a panel discussion press conference about the attempts to discover if there is moisture in the atmosphere of Jupiter. David Seidel, of the Jet Propulsion Laboratory (JPL) moderates the discussion. The panel consists of Andrew Ingersoll, California Institute of Technology, Tobias Owen, of the University of Hawaii, Glenn Orton, Robert Carlson of JPL, and Ashwin Vasavada, a graduate student at Cal Tech. Each of the panelists discusses evidence for moisture in Jupiter's atmosphere. They show video tapes of either animation or shots from the Galileo mission or diagrams of the atmosphere of Jupiter. The videos clips that are shown, include a brief summary of the Galileo mission. A diagram showing the layers of Jupiter's atmosphere is discussed. One panelist discusses and shows shots from the nightside of Jupiter. Another video clip shows evidence for convergence downdrafts around dry spots. Evidence for thunderstorms and updrafts is also reviewed. Shots of the giant red spot on Jupiter are shown, and explanations are given as to what it may be.

  1. Strong tidal dissipation in Io and Jupiter from astrometric observations.

    PubMed

    Lainey, Valéry; Arlot, Jean-Eudes; Karatekin, Ozgür; Van Hoolst, Tim

    2009-06-18

    Io is the volcanically most active body in the Solar System and has a large surface heat flux. The geological activity is thought to be the result of tides raised by Jupiter, but it is not known whether the current tidal heat production is sufficiently high to generate the observed surface heat flow. Io's tidal heat comes from the orbital energy of the Io-Jupiter system (resulting in orbital acceleration), whereas dissipation of energy in Jupiter causes Io's orbital motion to decelerate. Here we report a determination of the tidal dissipation in Io and Jupiter through its effect on the orbital motions of the Galilean moons. Our results show that the rate of internal energy dissipation in Io (k(2)/Q = 0.015 +/- 0.003, where k(2) is the Love number and Q is the quality factor) is in good agreement with the observed surface heat flow, and suggest that Io is close to thermal equilibrium. Dissipation in Jupiter (k(2)/Q = (1.102 +/- 0.203) x 10(-5)) is close to the upper bound of its average value expected from the long-term evolution of the system, and dissipation in extrasolar planets may be higher than presently assumed. The measured secular accelerations indicate that Io is evolving inwards, towards Jupiter, and that the three innermost Galilean moons (Io, Europa and Ganymede) are evolving out of the exact Laplace resonance.

  2. Automated Estimation of the Orbital Parameters of Jupiter's Moons

    NASA Astrophysics Data System (ADS)

    Western, Emma; Ruch, Gerald T.

    2016-01-01

    Every semester the Physics Department at the University of St. Thomas has the Physics 104 class complete a Jupiter lab. This involves taking around twenty images of Jupiter and its moons with the telescope at the University of St. Thomas Observatory over the course of a few nights. The students then take each image and find the distance from each moon to Jupiter and plot the distances versus the elapsed time for the corresponding image. Students use the plot to fit four sinusoidal curves of the moons of Jupiter. I created a script that automates this process for the professor. It takes the list of images and creates a region file used by the students to measure the distance from the moons to Jupiter, a png image that is the graph of all the data points and the fitted curves of the four moons, and a csv file that contains the list of images, the date and time each image was taken, the elapsed time since the first image, and the distances to Jupiter for Io, Europa, Ganymede, and Callisto. This is important because it lets the professor spend more time working with the students and answering questions as opposed to spending time fitting the curves of the moons on the graph, which can be time consuming.

  3. Colors and Properties of Jupiter's Greeks and Trojans

    NASA Astrophysics Data System (ADS)

    Chatelain, Joseph; Henry, Todd J.; French, Linda M.; Trilling, David E.

    2016-10-01

    In this Ph.D. talk, I will present the colors and properties of Jupiter Trojan asteroids examined in my dissertation research. The Jupiter Trojan asteroids are minor bodies that orbit 60 degrees in front and 60 degrees behind Jupiter. Because these orbits are stable over the lifetime of the Solar System, the properties of these objects may inform us about the conditions under which the Solar System formed. We present BVRKCIKC photometry for over 100 of the intrinsically brightest and presumably largest members of the L4 and L5 Jupiter Trojans. We use a new principal color component derived by Chatelain et al. 2016 that is indicative of taxonomic types relevant to the Jupiter Trojan asteroids. We previously found that 76% of the largest L5 Jupiter Trojans are consistent with a D-type classification, while 24% show shallower slopes more consistent with X-type and C-type classifications. Here we extend this study to the L4 cloud and compare the two populations, as well as include findings about specific objects that have resulted from these data. Specifically, multiple photometric observations hint at color variation in some objects, and our richest datasets allow for the determination of phase curves and shapes for a handful of the most compelling asteroids including a new shape model and pole solution for 1173 Anchises. Our goal is to use this study to shed light on these fascinating objects and to place the Trojans in context in the larger Solar System.

  4. Shoemaker-Levy 9/JUPITER Collision Update

    NASA Astrophysics Data System (ADS)

    1994-05-01

    There are many signs that the upcoming collision between comet Shoemaker-Levy 9 and giant planet Jupiter is beginning to catch the imagination of the public. Numerous reports in the various media describe the effects expected during this unique event which according to the latest calculations will start in the evening of July 16 and end in the morning of July 22, 1994. (The times in this Press Release are given in Central European Summer Time (CEST), i.e., Universal Time (UT) + 2 hours. The corresponding local time in Chile is CEST - 6 hours.) Astronomers all over the world are now preparing to observe the associated phenomena with virtually all major telescopes. There will be no less than 12 different investigations at the ESO La Silla observatory during this period. This Press Release updates the information published in ESO PR 02/94 (27 January 1994) and provides details about the special services which will be provided by ESO to the media around this rare astronomical event. SCIENTIFIC EXPECTATIONS The nucleus of comet Shoemaker-Levy 9 broke into many smaller pieces during a near passage of Jupiter in July 1992. They are now moving in parallel orbits around this planet and recent calculations show with close to 100 % certainty that they will all collide with it, just two months from now. At some time, more than 20 individual nuclei were observed. This Press Release is accompanied by a photo that shows this formation, the famous "string of pearls", as it looked like in early May 1994. Both Jupiter and these nuclei have been extensively observed during the past months. A large, coordinated observing programme at La Silla has been active since early April and the first results have become available. However, while we now possess more accurate information about the comet's motion and the times of impact, there is still great uncertainty about the effects which may actually be observed at the time of the impacts. This is first of all due to the fact that it has not

  5. Temperature Swings in a Hot Jupiter's Atmosphere

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-04-01

    Weather variations in the atmosphere of a planet on a highly eccentric orbit are naturally expected to be extreme. Now, a study has directly measured the wild changes in the atmosphere of a highly eccentric hot Jupiter as it passes close to its host star.Diagram of the HD 80606 system. The inset images labeled AH show the temperature distribution of the planet at different stages as it swings around its star. [de Wit et al. 2016]Eccentric OpportunityFor a hot Jupiter a gas giant that orbits close to its host star the exoplanet HD 80606 b exhibits a fairly unusual path. Rather than having a circularized orbit, HD 80606 b travels on an extremely elliptic 111-day orbit, with an eccentricity of e ~ 0.93. Since the amount of flux HD 80606 b receives from its host varies by a factor of ~850 over the course of its orbit, it stands to reason that this planet must have extreme weather swings!Now a team of scientists led by Julien de Wit (Massachusetts Institute of Technology) has reanalyzed old observations of HD 80606 and obtained new ones using the Spitzer Space Telescope. The longer observing time and new data analysis techniques allowed the team to gain new insights into how the exoplanets atmosphere responds to changes in the stellar flux it receives during its orbit.Extreme VariationsBy measuring the infrared light coming from HD 80606, de Wit and collaborators modeled the planets temperature during 80 hours of its closest approach to its host star. This period of time included the ~20 hours in which most of the planets temperature change is expected to occur, as it approaches to a distance a mere 6 stellar radii from its host.The authors find that the layer of the atmosphere probed by Spitzer heats rapidly from 500K to 1400K (thats ~440F to a scalding 2000+F!) as the planet approaches periastron.The atmosphere then cools similarly quickly as the planet heads away from the star once more.Relative infrared brightness of HD 80606 b at 4.5 and 8 m. The dip marks where

  6. THE CHANGE IN JUPITER'S MOMENT OF INERTIA DUE TO CORE EROSION AND PLANETARY CONTRACTION

    SciTech Connect

    Helled, Ravit

    2012-03-20

    We explore the change in Jupiter's normalized axial moment of inertia (NMOI) assuming that Jupiter undergoes core erosion. It is found that Jupiter's contraction combined with an erosion of 20 M{sub Circled-Plus} from a primordial core of 30 M{sub Circled-Plus} can significantly change Jupiter's NMOI over time. It is shown that Jupiter's NMOI could have changed from {approx}0.235 to {approx}0.264 throughout its evolution. We find that an NMOI value of {approx}0.235 as suggested by dynamical models could, in principle, be consistent with Jupiter's primordial internal structure. Low NMOI values, however, persist only for the first {approx}10{sup 6} years of Jupiter's evolution. Re-evaluation of dynamical stability models as well as more sophisticated evolution models of Jupiter with core erosion seem to be required in order to provide more robust estimates for Jupiter's primordial NMOI.

  7. Magnetohydrodynamic simulations of hot jupiter upper atmospheres

    SciTech Connect

    Trammell, George B.; Li, Zhi-Yun; Arras, Phil E-mail: zl4h@virginia.edu

    2014-06-20

    Two-dimensional simulations of hot Jupiter upper atmospheres including the planet's magnetic field are presented. The goal is to explore magnetic effects on the layer of the atmosphere that is ionized and heated by stellar EUV radiation, and the imprint of these effects on the Lyα transmission spectrum. The simulations are axisymmetric, isothermal, and include both rotation and azimuth-averaged stellar tides. Mass density is converted to atomic hydrogen density through the assumption of ionization equilibrium. The three-zone structure—polar dead zone (DZ), mid-latitude wind zone (WZ), and equatorial DZ—found in previous analytic calculations is confirmed. For a magnetic field comparable to that of Jupiter, the equatorial DZ, which is confined by the magnetic field and corotates with the planet, contributes at least half of the transit signal. For even stronger fields, the gas escaping in the mid-latitude WZ is found to have a smaller contribution to the transit depth than the equatorial DZ. Transmission spectra computed from the simulations are compared to Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys data for HD 209458b and HD 189733b, and the range of model parameters consistent with the data is found. The central result of this paper is that the transit depth increases strongly with magnetic field strength when the hydrogen ionization layer is magnetically dominated, for dipole magnetic field B {sub 0} ≳ 10 G. Hence transit depth is sensitive to magnetic field strength, in addition to standard quantities such as the ratio of thermal to gravitational binding energies. Another effect of the magnetic field is that the planet loses angular momentum orders of magnitude faster than in the non-magnetic case, because the magnetic field greatly increases the lever arm for wind braking of the planet's rotation. Spin-down timescales for magnetized models of HD 209458b that agree with the observed transit depth can be as

  8. Magnetohydrodynamic Simulations of Hot Jupiter Upper Atmospheres

    NASA Astrophysics Data System (ADS)

    Trammell, George B.; Li, Zhi-Yun; Arras, Phil

    2014-06-01

    Two-dimensional simulations of hot Jupiter upper atmospheres including the planet's magnetic field are presented. The goal is to explore magnetic effects on the layer of the atmosphere that is ionized and heated by stellar EUV radiation, and the imprint of these effects on the Lyα transmission spectrum. The simulations are axisymmetric, isothermal, and include both rotation and azimuth-averaged stellar tides. Mass density is converted to atomic hydrogen density through the assumption of ionization equilibrium. The three-zone structure—polar dead zone (DZ), mid-latitude wind zone (WZ), and equatorial DZ—found in previous analytic calculations is confirmed. For a magnetic field comparable to that of Jupiter, the equatorial DZ, which is confined by the magnetic field and corotates with the planet, contributes at least half of the transit signal. For even stronger fields, the gas escaping in the mid-latitude WZ is found to have a smaller contribution to the transit depth than the equatorial DZ. Transmission spectra computed from the simulations are compared to Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys data for HD 209458b and HD 189733b, and the range of model parameters consistent with the data is found. The central result of this paper is that the transit depth increases strongly with magnetic field strength when the hydrogen ionization layer is magnetically dominated, for dipole magnetic field B 0 >~ 10 G. Hence transit depth is sensitive to magnetic field strength, in addition to standard quantities such as the ratio of thermal to gravitational binding energies. Another effect of the magnetic field is that the planet loses angular momentum orders of magnitude faster than in the non-magnetic case, because the magnetic field greatly increases the lever arm for wind braking of the planet's rotation. Spin-down timescales for magnetized models of HD 209458b that agree with the observed transit depth can be as short

  9. Exploration of the Jovian System by EJSM (Europa Jupiter System Mission): Origin of Jupiter and Evolution of Satellites

    NASA Astrophysics Data System (ADS)

    Sasaki, Sho; Fujimoto, Masaki; Takashima, Takeshi; Yano, Hajime; Kasaba, Yasumasa; Takahashi, Yukihiro; Kimura, Jun; Okada, Tatsuaki; Kawakatsu, Yasuhiro; Tsuda, Yuichi; Kawaguchi, Jun-Ichiro; Funase, Ryu; Mori, Osamu; Morimoto, Mutsuko; Ikoma, Masahiro; Naganuma, Takeshi; Yamaji, Atsushi; Hussmann, Hauke; Kurita, Kei; Working Group, Jupiter

    EJSM (Europa Jupiter System Mission) is a planned Jovian system mission with three spacecraft aiming at coordinated observations of the Jovian satellites especially Europa and the magnetosphere, atmosphere and interior of Jupiter. It was formerly called "Laplace" mission. In October 2007, it was selected as one of future ESA scientific missions Cosmic Vision (2015-2025). From the beginning, Japanese group is participating in the discussion process of the mission. JAXA will take a role on the magnetosphere spinner JMO (Jupiter Magnetosphere Orbiter). On the other hand, ESA will take charge of JGO (Jupiter Ganymede Orbiter) and NASA will be responsible for JEO (Jupiter Europa Orbiter). In February 2009, EJSM is prioritized as the first candidate of outer planet flagship mission and mission study continues in the course of Cosmic Vision. The expected launch time of EJSM will be expected in 2020. Currently we are seeking a possibility to combine JMO with a proposed solar sail mission of JAXA for Jupiter and one of Trojan asteroids.

  10. JUPITER WILL BECOME A HOT JUPITER: CONSEQUENCES OF POST-MAIN-SEQUENCE STELLAR EVOLUTION ON GAS GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Madhusudhan, Nikku E-mail: Nikku.Madhusudhan@yale.edu

    2012-09-10

    When the Sun ascends the red giant branch (RGB), its luminosity will increase and all the planets will receive much greater irradiation than they do now. Jupiter, in particular, might end up more highly irradiated than the hot Neptune GJ 436b and, hence, could appropriately be termed a 'hot Jupiter'. When their stars go through the RGB or asymptotic giant branch stages, many of the currently known Jupiter-mass planets in several-AU orbits will receive levels of irradiation comparable to the hot Jupiters, which will transiently increase their atmospheric temperatures to {approx}1000 K or more. Furthermore, massive planets around post-main-sequence stars could accrete a non-negligible amount of material from the enhanced stellar winds, thereby significantly altering their atmospheric chemistry as well as causing a significant accretion luminosity during the epochs of most intense stellar mass loss. Future generations of infrared observatories might be able to probe the thermal and chemical structure of such hot Jupiters' atmospheres. Finally, we argue that, unlike their main-sequence analogs (whose zonal winds are thought to be organized in only a few broad, planetary-scale jets), red-giant hot Jupiters should have multiple, narrow jets of zonal winds and efficient day-night redistribution.

  11. JUpiter ICy moons Explorer (JUICE): An ESA mission to orbit Ganymede and to characterise the Jupiter system

    NASA Astrophysics Data System (ADS)

    Grasset, O.; Dougherty, M. K.; Coustenis, A.; Bunce, E. J.; Erd, C.; Titov, D.; Blanc, M.; Coates, A.; Drossart, P.; Fletcher, L. N.; Hussmann, H.; Jaumann, R.; Krupp, N.; Lebreton, J.-P.; Prieto-Ballesteros, O.; Tortora, P.; Tosi, F.; Van Hoolst, T.

    2013-04-01

    Past exploration of Jupiter's diverse satellite system has forever changed our understanding of the unique environments to be found around gas giants, both in our solar system and beyond. The detailed investigation of three of Jupiter's Galilean satellites (Ganymede, Europa, and Callisto), which are believed to harbour subsurface water oceans, is central to elucidating the conditions for habitability of icy worlds in planetary systems in general. The study of the Jupiter system and the possible existence of habitable environments offer the best opportunity for understanding the origins and formation of the gas giants and their satellite systems. The JUpiter ICy moons Explorer (JUICE) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015-2025, will perform detailed investigations of Jupiter and its system in all their inter-relations and complexity with particular emphasis on Ganymede as a planetary body and potential habitat. The investigations of the neighbouring moons, Europa and Callisto, will complete a comparative picture of the Galilean moons and their potential habitability. Here we describe the scientific motivation for this exciting new European-led exploration of the Jupiter system in the context of our current knowledge and future aspirations for exploration, and the paradigm it will bring in the study of giant (exo) planets in general.

  12. Preparations for VLBA Astrometry of Juno at Jupiter

    NASA Astrophysics Data System (ADS)

    Jones, Dayton L.; Folkner, William M.; Jacobson, Robert A.; Jacobs, Christopher S.; Romney, Jon; Dhawan, Vivek; Fomalont, Edward B.

    2016-01-01

    The Juno mission will provide a unique opportunity to improve our knowledge of the orbit of Jupiter. The Juno spacecraft has been on its way to Jupiter since August 2011, and will enter Jupiter orbit in July 2016. It will orbit the planet more than 30 times during following 1.5 years. This will allow us to improve the orbit of Jupiter in the planetary ephemeris by using the NRAO Very Long Baseline Array (VLBA) to measure precise sky positions of Juno during the orbital phase of its mission. These positions can be combined with orbit solutions for Juno about Jupiter from Deep Space Network tracking to determine positions for the Jupiter system barycenter. This is the same technique that we have used to improve the Saturn ephemeris with VLBA astrometry of Cassini during the past decade. Test observations of Juno with the VLBA have shown that it will provide position accuracies at least as good as Cassini, 0.2-0.4 milliarcseconds (1-2 nrad). This corresponds to errors of approximately 0.8-1.6 km at the average distance of Jupiter from Earth. All previous missions to Jupiter have been single-epoch flybys except for Galileo, whose high gain antenna failed to deploy. Consequently Juno will be our first opportunity to obtain routine sub-milliarcsecond positions for Jupiter during an extended period of time. As was the case for Saturn, we expect a factor of several improvement in Jupiter's orbit as a result of the planned VLBA astrometry of Juno.We gratefully acknowledge support of this project from NASA's Planetary Astronomy division through grant NNX15AJ11G to the Space Science Institute. Part of this research has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. The VLBA is part of the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under a cooperative agreement with Associated Universities, Inc. This work made use of the Swinburne University of Technology

  13. Jupiter's Global Winds in Advance of the Juno Encounters

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; Tollefson, Joshua; Simon, Amy A.; Cosentino, Rick; de Pater, Imke; Marcus, Philip; Orton, Glenn S.; Morales-Juberias, Raul; Johnson, Perianne

    2016-10-01

    We use Hubble/WFC3 imaging observations in February 2016 to derive Jupiter's global wind field, the closest wind velocity measurement to Juno's focused atmospheric campaign (November 2016 through January 2017).Using the methods of Asay-Davis et al. (2011, Icarus 211, 1215), we derive zonal wind profiles from Outer Planet Atmospheres Legacy (OPAL) program data in 2015 and 2016, and from 2009 and 2012 data, all taken at red optical wavelengths with the WFC3/UVIS instrument. Several jets show significant variability in peakspeed over the 2000-2016 time period, while most jets are very stable.We quantify uncertainties in order to determine which changes are significant, and we find a roughly 2x improvement in precision compared to the HST/WFPC2 and Cassini-derived zonal wind profiles in Asay-Davis et al. (2011). Some improvement in precision is likely to be instrumental. The WFC3/UVIS detector better samples the HST point-spread function by about 15% compared to WFPC2, and the larger WFC3/UVIS field of view reduces navigational uncertainty by capturing the entire planetary disk in every image. It is not yet clear whether instrumental effects can explain the entire reduction in uncertainty, which could potentially include time-variable noise due to coherent features (waves, vortices) as well as turbulence. Global variability of this magnitude would be a surprise, since Asay-Davis et al. (2011) found the same level of velocity uncertainty (~11 m/s) in both Cassini data from 2000 and HST/WFPC2 data from 2008.We will generate spatial spectra of kinetic energy and cloud features (in multiple filters), using Fourier transforms of OPAL Jupier imaging data and 2D velocity fields. We will fit composite linear models (Barrado-Izagirre et al. 2009, Icarus 202, 181; Choi and Showman 2011, Icarus 216, 597) to the kinetic energy and cloud albedo spectra, comparing spectral indices to past observations and determining forcing scales.

  14. Tidal reorientation and the fracturing of Jupiter's moon Europa

    USGS Publications Warehouse

    McEwen, A.S.

    1986-01-01

    The most striking characteristic of Europa is the network of long linear albedo markings over the surface, suggestive of global-scale tectonic processes. Various explanations for the fractures have been proposed: Freezing and expansion of an early liquid water ocean1, planetary expansion due to dehydration of hydrated silicates2, localization by weak points in the crust generated by impacts3, and a combination of stresses due to planetary volume change and tidal distortions from orbital recession and orbital eccentricity4,5. Calculations by Yoder6 and Greenberg and Weidenschilling7 have shown that Europa may rotate slightly more rapidly than the synchronous rate, with a rotation period (reorientation through 360??) ranging from 20 to >103 yr if a liquid mantle is present, or up to 1010 yr if the satellite is essentially solid7. Helfen-stein and Parmentier8 modelled the stresses due to nonsynchronous rotation, and concluded that this could explain the long fractures in part of the anti-jovian hemisphere. In this note, I present a global map of lineaments with long arc lengths (>20?? or 550 km), and compare the lineament orientations to the tensile stress trajectories due to tidal distortions (changes in the lengths of three principal semiaxes) and to nonsynchronous rotation (longitudinal reorientation of two of the principal semiaxes). An excellent orthogonal fit to the lineaments is achieved by the stresses due to nonsynchronous rotation with the axis radial to Jupiter located 25?? east of its present position. This fit suggests that nonsynchronous rotation occurred at some time in Europa's history. ?? 1986 Nature Publishing Group.

  15. Tidal Heating in a Magma Ocean within Jupiter's Moon Io

    NASA Astrophysics Data System (ADS)

    Tyler, Robert H.; Henning, Wade G.; Hamilton, Christopher W.

    2015-06-01

    Active volcanism observed on Io is thought to be driven by the temporally periodic, spatially differential projection of Jupiter's gravitational field over the moon. Previous theoretical estimates of the tidal heat have all treated Io as essentially a solid, with fluids addressed only through adjustment of rheological parameters rather than through appropriate extension of the dynamics. These previous estimates of the tidal response and associated heat generation on Io are therefore incomplete and possibly erroneous because dynamical aspects of the fluid behavior are not permitted in the modeling approach. Here we address this by modeling the partial-melt asthenosphere as a global layer of fluid governed by the Laplace Tidal Equations. Solutions for the tidal response are then compared with solutions obtained following the traditional solid-material approach. It is found that the tidal heat in the solid can match that of the average observed heat flux (nominally 2.25 W m-2), though only over a very restricted range of plausible parameters, and that the distribution of the solid tidal heat flux cannot readily explain a longitudinal shift in the observed (inferred) low-latitude heat fluxes. The tidal heat in the fluid reaches that observed over a wider range of plausible parameters, and can also readily provide the longitudinal offset. Finally, expected feedbacks and coupling between the solid/fluid tides are discussed. Most broadly, the results suggest that both solid and fluid tidal-response estimates must be considered in exoplanet studies, particularly where orbital migration under tidal dissipation is addressed.

  16. Distribution of (S II) emission around Jupiter

    SciTech Connect

    Pilcher, C.B.; Morgan, J.S.

    1980-05-15

    We have studied the distribution and intensity of the ''nebular'' (S II) emission (lambdalambda6716, 67731) around Jupiter over a 3 month interval beginning in 1977 December. The data presented here are 46 low-dispersion spectra with high temporal resolution (approx.2.5 minutes) obtained on the 2.2 m telescope at Mauna Kea Observatory. We find that the emission is in the form of a ring in the vicinity of the Jovian magnetic equator with radial limits between 4 and 7 R/sub j/. The ring thickness perpendicular to the magnetic equator is at times at least +- 0.7 R/sub j/, but is almost certainly quite variable. The emission is frequently observable primarily over the approx.180 /sup 0/ of magnetic longitude centered aroung 250 /sup 0/ (lambda/sub III/ (1965)). We propose that this variation in intensity with longitude is caused by preferential plasma loading of field lines associated with the Io-induced Jovian decametric bursts. There is no correlation of emission intensity with the orbital position of Io. The absolute emission intensities vary from approx.200 to approx.500 Rayleighs.

  17. EUVE Observations of the Jupiter System

    NASA Technical Reports Server (NTRS)

    Schneider, Nicholas M.

    2000-01-01

    This document is the final report for NASA Grant NAG5-4615, 'Satellie Atmosphere and Io Torus Observations', Nicholas M. Schneider, P.I., awarded to the University of Colorado, 8/l/97-3/31/00. The grant was originally awarded to Dr. Doyle T. Hall, who left the University of Colorado before the completion of the project. Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to a host of scientifically compelling phenomena, including (1) an atmosphere out of proportion with such a small object, (2) a correspondingly large atmospheric escape rate, (3) a ring of dense plasma locked in a feedback loop with the atmosphere, and (4) a host of Io-induced emissions from radio bursts to UV auroral spots on Jupiter. This proposal seeks to continue our investigation into the physics connecting these phenomena, with emphasis on Io's atmosphere and plasma torus. The physical processes are clearly of interest for Io, and also other places in the solar system where they are important but not readily observable.

  18. Magnetic fields of Jupiter and Saturn

    SciTech Connect

    Ness, N.F.

    1981-01-01

    The magnetic fields of Jupiter and Saturn and the characteristics of their magnetospheres, formed by interaction with the solar wind, are discussed. The origins of both magnetic fields are associated with a dynamo process deep in the planetary interior. The Jovian magnetosphere is analogous to that of a pulsar magnetosphere: a massive central body with a rapid rotation and an associated intense magnetic field. Its most distinctive feature is its magnetodisk of concentrated plasma and particle flux, and reduced magnetic field intensity. The magnetopause near the subsolar point has been observed at radial distances ranging over 50 to 100 Jovian radii, implying a relatively compressible obstacle to solar wind flow. The composition of an embedded current sheet within the magnetic tail is believed to be influenced by volcanic eruptions and emissions from Io. Spectral troughs of the Jovian radiation belts have been interpreted as possible ring particles. The Saturnian magnetosphere appears to be more like the earth in its topology. It is mainly characterized by a dipole axis parallel to the rotational axis of the planet and a magnetic field intensity much less than expected.

  19. Cassini/CIRS results on Jupiter

    NASA Astrophysics Data System (ADS)

    Fouchet, T.; Flasar, M.; Kunde, V.

    The Composite Infrared Spectrometer (CIRS) on board the Cassini orbiter covers the 10-1600 cm-1 at a maximun apodized spectral resolution of 0.5 cm-1. En route to Saturn, Cassini performed a fly-by of Jupiter with a closest approach of ˜10^7 kilometers. At this distance, the spatial resolution on the planet was 2.5 degrees of latitude and longitude at the equator. This dataset was used to map with unprecedented details the spatial variations of the Jovian temperature field (Flasar et al.), and of the Jovian composition field for C_2H_2 and C_2H_6 (Nixon et al.), PH_3 (Irwin et al.), 15N/14N (Abbas et al.; Fouchet et al.). CIRS also detected a new molecule and a radical, C_4H_2 and CH_3 (Kunde et al.). Here, we will present a summary of these investigations and their consequences for our understanding of the chemistry and meteorology of the Giant Planet.

  20. Voyager spacecraft images of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Birnbaum, M. M.

    1982-01-01

    The Voyager imaging system is described, noting that it is made up of a narrow-angle and a wide-angle TV camera, each in turn consisting of optics, a filter wheel and shutter assembly, a vidicon tube, and an electronics subsystem. The narrow-angle camera has a focal length of 1500 mm; its field of view is 0.42 deg and its focal ratio is f/8.5. For the wide-angle camera, the focal length is 200 mm, the field of view 3.2 deg, and the focal ratio of f/3.5. Images are exposed by each camera through one of eight filters in the filter wheel on the photoconductive surface of a magnetically focused and deflected vidicon having a diameter of 25 mm. The vidicon storage surface (target) is a selenium-sulfur film having an active area of 11.14 x 11.14 mm; it holds a frame consisting of 800 lines with 800 picture elements per line. Pictures of Jupiter, Saturn, and their moons are presented, with short descriptions given of the area being viewed.

  1. Cold Friends of Hot Jupiters: NIRSPEC Survey

    NASA Astrophysics Data System (ADS)

    Piskorz, Danielle; Knutson, H. A.; Muirhead, P. S.; Batygin, K.; Crepp, J. R.; Hinkley, S.; Howard, A. W.; Johnson, J. A.; Morton, T. D.

    2013-10-01

    Previous surveys have shown that half of all stars occur in binary systems. Although most exoplanet surveys exclude systems with known binary companions, it is likely that many known planetary systems contain distant, low-mass stellar companions that went unnoticed in the initial survey selection. Such companions may have important effects on the formation and migration of planets (and especially hot Jupiters) around the primary star via three-body interactions such as Kozai-driven migration. The Cold Friends project uses three observing techniques to make a robust determination of the occurrence rate of exoplanets in binary systems: radial velocity monitoring, adaptive optics imaging (see presentation on the AO Survey by H. Ngo et al.), and near-infrared spectroscopy. In this presentation, we focus on the results of the spectroscopy portion of the Cold Friends project. Using NIRSPEC at Keck Observatory, we have obtained high-resolution spectra of roughly fifty exoplanet-hosting stars near 2.3 microns, where low-mass companions will show deep CO absorption features superimposed on the primary stellar spectrum. This method allows for the detection of binary companions located within 50 to 200 AU of the host star. At this location, such a binary companion could conceivably influence the formation and migration of exoplanets orbiting the main star. We describe our method for removing the signal due to the main-sequence FGK host stars and searching for the distinctive spectral features of a low-mass stellar companion.

  2. Energetic electrons in the magnetosphere of jupiter.

    PubMed

    Van Allen, J A; Baker, D N; Randall, B A; Thomsen, M F; Sentman, D D; Flindt, H R

    1974-01-25

    Observations of energetic electrons ( greater, similar 0.07 million electron volts) show that the outer magnetosphere of Jupiter consists of a thin disklike, quasitrapping region extending from about 20 to 100 planetary radii (R(J)). This magnetodisk is confined to the vicinity of the magnetic equatorial plane and appears to be an approximate figure of revolution about the magnetic axis of the planet. Hard trapping is observed within a radial distance of about 20 R(J). The omnidirectional intensity J(0) of electrons with energy greater, similar 21 million electron volts within the region 3 r 20 R(J) is given by the following provisional expression in terms of radial distance r and magnetic latitude theta: J(0) = 2.1 x 10(8) exp[-(r/a) - (theta/b)(2)]. In this expression J(0) is particles per square centimeter per second; a = 1.52 R(J) for 3

  3. The magnetic fields of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Ness, N. F.

    The magnetic fields of Jupiter and Saturn and the characteristics of their magnetospheres, formed by interaction with the solar wind, are discussed. The origins of both magnetic fields are associated with a dynamo process deep in the planetary interior. The Jovian magnetosphere is analogous to that of a pulsar magnetosphere: a massive central body with a rapid rotation and an associated intense magnetic field. Its most distinctive feature is its magnetodisk of concentrated plasma and particle flux, and reduced magnetic field intensity. The magnetopause near the subsolar point has been observed at radial distances ranging over 50 to 100 Jovian radii, implying a relatively compressible obstacle to solar wind flow. The composition of an embedded current sheet within the magnetic tail is believed to be influenced by volcanic eruptions and emissions from Io. Spectral troughs of the Jovian radiation belts have been interpreted as possible ring particles. The Saturnian magnetosphere appears to be more like the earth in its topology. It is mainly characterized by a dipole axis parallel to the rotational axis of the planet and a magnetic field intensity much less than expected.

  4. Strange Latitudinal Variations of the Ammonia Absorption on Jupiter

    NASA Astrophysics Data System (ADS)

    Tejfel, V. G.; Karimov, A. M.; Vdovichenko, V. D.

    2005-08-01

    The ammonia absorption bands at near infrared spectrum of Jupiter are blended with stronger methane absorption and it is hard to study their variations on planetary disk. To extract the ammonia absorption we have used the ratio of Jupiter's spectra to the spectrum of Saturn where the ammonia absorption is very small or absent. Thus we could measure the profile and equivalent widths (W) of the NH3 band at 787 nm as well as the weaker band at 643 nm . More than 200 spectra of Jupiter were recorded in March-May 2004 with spectrograph SGS and CCD-camera ST-7XE at the slit oriented along central meridian or equator. All spectra were processed by this mean. Equatorial spectra show more or less uniform decrease of the NH3 absorption towards both limbs from the disk center. But most of spectra of CM show strange and clearly expressed wide depression of the NH3 band at 787 nm in the temperate latitudes of Northern hemisphere with minimal equivalent widths about 15 A or less when W in Southern hemisphere reach of 20 A or more. We have analyzed all probable artificial reasons of this effect but did not find any influence of instrumental factors. Then we processed a number of Jupiter's spectra recorded in 1997-1998 with other spectrograph and CCD ST-6V and detected the same peculiarity. Finally there were measured 100 zonal spectra ( with slit oriented parallel to equator) scanned all Jupiter's disk from North pole to South pole and recorded 3 May 2005 near upper culmination of the planet. The result is the same: the significant depression of the ammonia absorption in the N-hemisphere of Jupiter is confirmed. We shall continue the study and analysis of this effect to be sure that it is real peculiarity of the gaseous ammonia distribution and behavior on Jupiter.

  5. Science Rationale for Jupiter Entry Probe as Part of JIMO

    NASA Technical Reports Server (NTRS)

    Young, R. E.; Spilker, T. R.

    2003-01-01

    A Jupiter atmospheric entry probe as part of JIMO is a cost effective way to address fundamental science questions identified in the National Research Council Solar System Exploration Decadal Survey (SSEDS): New Frontiers in the Solar System, An Integrated Ex- ploration Strategy. Compared to either the cost of an entirely separate Jupiter mission, or the cost of JIMO itself, inclusion of such a probe on JIMO would be cost advantageous. The probe itself could be relatively simple, and could build on the Galileo Probe heritage. The SSEDS specifically identified the distribution of water across the Solar System as a Key Scientific Question. Correspondingly, knowing the water abun dance on Jupiter is fundamental to understanding almost every aspect of the evolution of the early solar nebula. The Galileo Probe obtained the abundance of several key elements in Jupiter's atmosphere, which data have already caused major rethinking of theories of how Jupiter formed and how the early solar nebula evolved. However, because of a combination of circumstances, the global abundance of the key element oxygen, in the form of water, was not obtained. Without knowledge of the jovian water abundance, further progress in understanding Solar System evolution and planet formation will be greatly inhibited. Therefore, quantifying jovian water abundance should be a goal of the very next mission to the jovian system. Such a measurement would be impossible via remote sensing from the JIMO orbiter because of the large distances the JIMO orbiter maintains from Jupiter. A Jupiter atmospheric entry probe as part of JIMO could achieve the fundamental water measurement. In order that a probe avoid repeating the Galileo probe's experience of failing to obtain the jovian water abundance, the probe should go deep, to at least 100 bars pressure. Probes to 100 bars have been accomplished many times in descending to the surface of Venus, and at 100 bars the temperature of the jovian atmosphere is 60

  6. Source Regions of Energetic Neutral Atoms From Jupiter

    NASA Astrophysics Data System (ADS)

    Mauk, B. H.; Mitchell, D. G.; Paranicas, C. P.; Roelof, E. C.; Krimigis, S. M.

    2002-12-01

    We have discovered that two discrete source regions dominate the emission fluxes of energetic neutral atoms (ENAs) from Jupiter's space environment in the 10's of keV energy range. The source regions are: 1) a ring or torus of emission just beyond the orbit of Europa, and 2) Jupiter's exosphere which glows in ENAs as a result of the near-precipitation of energetic ions onto Jupiter's atmosphere. To identify these sources we: i) deconvolved the instrument response from the ENA images obtained by the Cassini Ion and Neutral Camera during the Cassini flyby of Jupiter in January of 2001 (Krimigis et al., 2002), and ii) combined the images with in situ data obtained from the Galileo Energetic Particle Detector (EPD). The trans-Europa ENA emission source requires neutral densities greater than 10 / cc, and perhaps 10's per cc depending on the exact distribution of the ENA emissions. Thus, we hereby confirm the inference of Lagg et al. (2001), developed using Galileo EPD energetic-ion angle distributions, of the presence of a much denser population of neutral gas in the vicinity of Europa than has been predicted on the basis of the volcanic sources at Io. The Jupiter exospheric ENA source strength offers the most direct measure yet obtained of the flux of energetic ions precipitating over all onto Jupiter's atmosphere. Krimigis et al., A nebula of gasses from Io surrounding Jupiter, Nature, 415, 994, 2002. Lagg, A., N. Krupp, J. Woch, and D. J. Williams, Evidence for an extended neutral torus at Europa, Unpublished Manuscript, 2001.

  7. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion.

    PubMed

    Sing, David K; Fortney, Jonathan J; Nikolov, Nikolay; Wakeford, Hannah R; Kataria, Tiffany; Evans, Thomas M; Aigrain, Suzanne; Ballester, Gilda E; Burrows, Adam S; Deming, Drake; Désert, Jean-Michel; Gibson, Neale P; Henry, Gregory W; Huitson, Catherine M; Knutson, Heather A; des Etangs, Alain Lecavelier; Pont, Frederic; Showman, Adam P; Vidal-Madjar, Alfred; Williamson, Michael H; Wilson, Paul A

    2016-01-01

    Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.

  8. THE MECHANICAL GREENHOUSE: BURIAL OF HEAT BY TURBULENCE IN HOT JUPITER ATMOSPHERES

    SciTech Connect

    Youdin, Andrew N.; Mitchell, Jonathan L.

    2010-10-01

    The intense irradiation received by hot Jupiters suppresses convection in the outer layers of their atmospheres and lowers their cooling rates. 'Inflated' hot Jupiters, i.e., those with anomalously large transit radii, require additional sources of heat or suppressed cooling. We consider the effect of forced turbulent mixing in the radiative layer, which could be driven by atmospheric circulation or by another mechanism. Due to stable stratification in the atmosphere, forced turbulence drives a downward flux of heat. Weak turbulent mixing slows the cooling rate by this process, as if the planet were irradiated more intensely. Stronger turbulent mixing buries heat into the convective interior, provided the turbulence extends to the radiative-convective boundary. This inflates the planet until a balance is reached between the heat buried into and radiated from the interior. We also include the direct injection of heat due to the dissipation of turbulence or other effects. Such heating is already known to slow planetary cooling. We find that dissipation also enhances heat burial from mixing by lowering the threshold for turbulent mixing to drive heat into the interior. Strong turbulent mixing of heavy molecular species such as TiO may be necessary to explain stratospheric thermal inversions. We show that the amount of mixing required to loft TiO may overinflate the planet by our mechanism. This possible refutation of the TiO hypothesis deserves further study. Our inflation mechanism requires a deep stratified layer that only exists when the absorbed stellar flux greatly exceeds the intrinsic emitted flux. Thus, it would be less effective for more luminous brown dwarfs and for longer period gas giants, including Jupiter and Saturn.

  9. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion.

    PubMed

    Sing, David K; Fortney, Jonathan J; Nikolov, Nikolay; Wakeford, Hannah R; Kataria, Tiffany; Evans, Thomas M; Aigrain, Suzanne; Ballester, Gilda E; Burrows, Adam S; Deming, Drake; Désert, Jean-Michel; Gibson, Neale P; Henry, Gregory W; Huitson, Catherine M; Knutson, Heather A; des Etangs, Alain Lecavelier; Pont, Frederic; Showman, Adam P; Vidal-Madjar, Alfred; Williamson, Michael H; Wilson, Paul A

    2016-01-01

    Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures. PMID:26675732

  10. Mass Losses Of Co, Cs And Hcn On Jupiter/sl9

    NASA Astrophysics Data System (ADS)

    Moreno, Raphael; Marten, A.

    2006-09-01

    Since comet Shoemaker-Levy 9 (SL9) collided with Jupiter in 1994, the IRAM 30-m Telescope (Pico Veleta, Spain) and the 15-m JCMT (Mauna Kea,Hawaii) have regularly observed Jupiter at millimeter/submillimeter wavelengths. Molecular trace species such as HCN, CO, CS and their isotopomers have been detected in the upper atmosphere since the collision. Because of the high spectral resolution attained, our data allow one to infer both temperature and abundances in Jupiter's stratosphere with a maximum spatial resolution of 10 arcsec. We have used all these data to monitor the latitudinal spreading since the impacts occurred (Marten et al. 1995), to look for changes in their abundances with time (Moreno et al. 2001, 2003) and to determine several isotopic ratios (Matthews et al. 2002). Data taken in 2004 have shown that latitudinal distributions of all these species were almost homogeneous 10 years after impacts, as predicted by Moreno et al. 2003. Moreover, compared to 1998 results, respective mass loss factors as high as 2-7 have been determined for the three molecular main compounds (Moreno et al. 2005). In order to follow-up our monitoring, new disk mapping observations took place in May 2006 using the IRAM-30m Telescope. Here we report the results of the recent measurements of CO, CS and HCN, and also the search for new species: H2CO, H2CS, CH3CN, CH3OH. Such trace compounds could have explained the mass losses observed in 2004, but no clear detections have been obtained after reasonable integration times. Estimates of the new CO, CS and HCN total masses and upper limits for the trace species searched for will be presented. The loss mechanisms will be discussed. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  11. Identification of a magnetic anomaly at Jupiter from satellite footprints

    NASA Astrophysics Data System (ADS)

    Grodent, Denis

    2004-07-01

    Repeated imaging of Jupiter's aurora has shown that the northern main oval has a distorted 'kidney bean' shape in the general range of 90-140? System III longitude, which appears unchanged since 1994. While it is more difficult to observe the conjugate regions in the southern aurora, no corresponding distortion appears in the south. Recent improved accuracy in locating the satellite footprint auroral emissions has provided new information about the geometry of Jupiter's magnetic field in this and other areas. The study of the magnetic field provides us with insight into the state of matter and the dynamics deep down Jupiter. There is currently no other way to do this from orbit. The persistent pattern of the main oval implies a disturbance of the local magnetic field, and the increased latitudinal separation of the locus of satellite footprints from each other and from the main oval implies a locally weaker field strength. It is possible that these phenomena result from a magnetic anomaly in Jupiter's intrinsic magnetic field, as was proposed by A. Dessler in the 1970's. There is presently only limited evidence from the scarcity of auroral footprints observed in this longitude range. We propose to obtain HST UV images with specific observing geometries of Jupiter to determine the locations of the auroral footprints of Io, Europa, and Ganymede in cycle 13 to accurately determine the magnetic field geometry in the suggested anomaly region, and to either confirm or refute the suggestion of a local magnetic anomaly.

  12. Mean Molecular Weight Gradients in Proto-Jupiter

    NASA Astrophysics Data System (ADS)

    Helled, R.; Bodenheimer, P.; Rosenberg, E. D.; Podolak, M.; Lozovsky, M.

    2015-12-01

    The distribution of heavy elements in Jupiter cannot be directly measured, and must be inferred from structure models. Typically, structure models assume that Jupiter is fully convective with the heavy elements being uniformly distributed. However, in the case of layered-convection there is a gradient in the distribution of heavy elements which affects the temperature profile of the planet, and as a result also its derived composition. We simulate the formation of Jupiter and investigate whether mean molecular weight gradients that can lead to layered-convection are created. We show that planetesimal accretion naturally leads to compositional gradients in the region above the core. It is shown that after about 10^5 years the core of Jupiter is hot and is surrounded by layers that consist mostly heavy-elements but also some hydrogen and helium. As a result, Jupiter's core mass is expected to be 2-5 M_Earth with no sharp transition between the core and the envelope. These findings are important for the interpretation of Juno data and for linking giant planet internal structure with origins.

  13. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    SciTech Connect

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G.

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  14. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    USGS Publications Warehouse

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  15. Imaging Jupiter Radiation Belts At Low Frequencies

    NASA Astrophysics Data System (ADS)

    Girard, J. N.; de Pater, I.; Zarka, P.; Santos-Costa, D.; Sault, R.; Hess, S.; Cecconi, B.; Fender, R.; Pewg, Lofar

    2014-04-01

    The ultra-relativistic electrons, trapped in the inner radiation belts of Jupiter, generates a strong synchrotron radio emission (historically known as the jovian decimeter radiation (DIM)) which is beamed, polarized (~20% linear, ~1% circular) and broadband. It has been extensively observed by radio telescopes/ probes and imaged by radio interferometers over a wide frequency spectrum (from >300 MHz up to 22 GHz). This extended emission presents two main emission peaks constantly located on both sides of the planet close to the magnetic plane. High latitude emissions were also regularly observed at particular frequencies, times and in particular observational configurations. This region of the magnetosphere is "frozen" due to the strong magnetic field (~4.2 G as the equator) and therefore is forced to rotate at the planetary period (T≈9h55m). Due to the tilt (~ 10o) between the spin axis of the planet and the magnetic axis (which can be seen as dipolar in first approximation), the belts and the associated radio emission wobble around the planet center. The analysis of the flux at different frequencies highlighted spatial, temporal and spectral variabilities which origins are now partly understood. The emission varies at different time scales (short-time variations of hours to long-term variation over decades) due to the combination of visibility effect (wobbling, beaming, position of the observer in the magnetic rotating reference frame) [1], [2] and intrinsic local variations (interaction between relativistic electrons and satellites/dust, delayed effect of the solar wind ram pressure, impacts events) [3], [4], [5]. A complete framework is necessary to fully understand the source, loss and transport processes of the electrons originating from outside the belt, migrating by inward diffusion and populating the inner region of the magnetosphere. Only a few and unresolved measurements were made below 300 MHz and the nonsystematic observation of this radio emission

  16. Chemical uncertainties in modeling hot Jupiters atmospheres

    NASA Astrophysics Data System (ADS)

    Hebrard, Eric; Domagal-Goldman, Shawn

    2015-11-01

    Most predictions and interpretations of observations in beyond our Solar System have occurred through the use of 1D photo-thermo-chemical models. Their predicted atmospheric compositions are highly dependent on model parameters. Chemical reactions are based on empirical parameters that must be known at temperatures ranging from 100 K to above 2500 K and at pressures from millibars to hundreds of bars. Obtained from experiments, calculations and educated-guessed estimations, these parameters are always evaluated with substantial uncertainties. However, although of practical use, few models of exoplanetary atmospheres have considered these underlying chemical uncertainties and their consequences. Recent progress has been made recently that allow us to (1) evaluate the accuracy and precision of 1D models of planetary atmospheres, with quantifiable uncertainties on their predictions for the atmospheric composition and associated spectral features, (2) identify the ‘key parameters’ that contribute the most to the models predictivity and should therefore require further experimental or theoretical analysis, (3) reduce and optimize complex chemical networks for their inclusion in multidimensional atmospheric models.First, a global sampling approach based on low discrepancy sequences has been applied in order to propose error bars on simulations of the atmospheres HD 209458b and HD 189733b, using a detailed kinetic model derived from applied combustion models that was methodically validated over a range of temperatures and pressures typical for these hot Jupiters. A two-parameters temperature-dependent uncertainty factor has been assigned to each considered rate constant. Second, a global sensitivity approach based on high dimensional model representations (HDMR) has been applied in order to identify those reactions which make the largest contributions to the overall uncertainty of the simulated results. The HDMR analysis has been restricted to the most important

  17. Impacts with the Earth and Jupiter

    NASA Technical Reports Server (NTRS)

    Morrison, David

    1994-01-01

    The Earth has been subject to impacts from comets and asteroids since its formation, and such impacts have played an important role in the evolution of life on our planet. We now recognize not only the historical role of impacts, but the contemporary hazard posed by such events. In the absence of a complete census of potentially threatening Earth-crossing asteroids or comets (called collectively Near Earth Objects, or NEOs), or even of a comprehensive current search program to identify NEOs, we can consider the hazard only from a probabilistic perspective. In general, the larger the object the greater the hazard, even when allowance is made for the infrequency of large impacts. Most of the danger to human life is associated with impacts by objects roughly 2 km or larger (energy greater than 1 million megatons), which can inject sufficient submicrometer dust into the atmosphere to produce a severe short-term global cooling with subsequent loss of crops, leading to starvation. Hazard estimates suggest that the chance of such an event occurring during a human lifetime is about 1:5000, and the global probability of death from such impacts is of the order of 1:20000, values that can be compared with risks associated with other natural hazards such as earthquakes, volcanic eruptions, and severe storms. The widely-observed impact of Comet Shoemaker-Levy 9 with Jupiter in July 1994 provides a graphic example of such an interplanetary collision and is stimulating worldwide interest in protecting our planet against cosmic impact catastrophes.

  18. Limits to Determining the Core of Jupiter

    NASA Astrophysics Data System (ADS)

    Stevenson, David J.

    2016-10-01

    Simple, approximate models based on perturbations of the n=1 polytrope are used to identify some general properties of models for nearly-isentropic Jupiter-like planets where the total heavy element mass fraction is small. In these models, it is found that the radius is remarkably insensitive to the distribution of heavy elements and is effectively a measure of total heavy element enrichment (sum of core and envelope). The gravity harmonic J2 and the normalized moment of inertia α=I/MR2 are almost entirely determined by the density structure outside the core, and this depends on the reduced core mass, defined to be the actual core mass minus the mass of hydrogen and helium that would occupy that region in the absence of the core. The actual core mass or its radius or composition cannot be well determined, even when there is perfect knowledge of the equation of state, thermal state and envelope enrichment by heavy elements. The central concentration of heavy elements is approximately determined, even when the actual core is more massive and contaminated with hydrogen and helium by mixing or erosion (double diffusive convection). At fixed J2, the dependence of α on core structure is very small, and only exceeds the likely detection limit ~0.1-0.2% for very extended cores. Even though these results are obtained for a simple model, it is argued that they are semi-quantitatively applicable to realistic models. A perturbation scheme is presented for testing this systematically and for assessing the consequences of perturbations to the equation of state, compositional profile and temperature structure for the trade-off between reduced core mass and envelope enrichment.

  19. The mass disruption of Jupiter Family comets

    NASA Astrophysics Data System (ADS)

    Belton, Michael J. S.

    2015-01-01

    I show that the size-distribution of small scattered-disk trans-neptunian objects when derived from the observed size-distribution of Jupiter Family comets (JFCs) and other observational constraints implies that a large percentage (94-97%) of newly arrived active comets within a range of 0.2-15.4 km effective radius must physically disrupt, i.e., macroscopically disintegrate, within their median dynamical lifetime. Additional observational constraints include the numbers of dormant and active nuclei in the near-Earth object (NEO) population and the slope of their size distributions. I show that the cumulative power-law slope (-2.86 to -3.15) of the scattered-disk TNO hot population between 0.2 and 15.4 km effective radius is only weakly dependent on the size-dependence of the otherwise unknown disruption mechanism. Evidently, as JFC nuclei from the scattered disk evolve into the inner Solar System only a fraction achieve dormancy while the vast majority of small nuclei (e.g., primarily those with effective radius <2 km) break-up. The percentage disruption rate appears to be comparable with that of the dynamically distinct Oort cloud and Halley type comets (Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A., Bottke Jr., W.F. [2002]. Science 296, 2212-2215) suggesting that all types of comet nuclei may have similar structural characteristics even though they may have different source regions and thermal histories. The typical disruption rate for a 1 km radius active nucleus is ∼5 × 10-5 disruptions/year and the dormancy rate is typically 3 times less. We also estimate that average fragmentation rates range from 0.01 to 0.04 events/year/comet, somewhat above the lower limit of 0.01 events/year/comet observed by Chen and Jewitt (Chen, J., Jewitt, D.C. [1994]. Icarus 108, 265-271).

  20. Infrared spectroscopy of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Knacke, Roger F.

    1993-01-01

    Infrared spectroscopy provides unique insights into the chemistry and dynamics of the atmospheres of Jupiter, Saturn, and Titan. In 1991 we obtained data at J, H, K, and M and made repeated observations of Titan's albedo as the satellite orbited Saturn. The J albedo is 12% +/- 3% greater than the albedo measured in 1979; the H and K albedos are the same. There was no evidence for variations at any wavelength over the eastern half of Titan's orbit. We also obtained low resolution (R=50) spectra of Titan between 3.1 and 5.1 microns. The spectra contain evidence for CO and CH3D absorptions. Spectra of Callisto and Ganymede in the 4.5 micron spectral region are featureless and give albedos of 0.08 and 0.04 respectively. If Titan's atmosphere is transparent near 5 microns, its surface albedo there is similar to Callisto's. In 1992 and 1993 we obtained further spectroscopic data of Titan with the UKIRT CGS4 spectrometer. We discovered two unexpected and unexplained spectral features in the 3-4 micron spectrum of Titan. An apparent emission feature near the 3 micron (nu sub 3) band of methane indicated temperatures higher than known to be present in Titan's upper stratosphere and may be caused by unexpected non-LTE emission. An absorption feature near 3.47 microns may be caused by absorption in solid grains or aerosols in Titan's clouds. The feature is similar but not identical to organics in the interstellar matter and in comets.

  1. On the Long-Term Variability of Jupiter's Winds and Brightness as Observed from Hubble

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Gierasch, Peter J.

    2010-01-01

    Hubble Space Telescope Wide Field Planetary Camera 2 imaging data of Jupiter were combined with wind profiles from Voyager and Cassini data to study long-term variability in Jupiter's winds and cloud brightness. Searches for evidence of wind velocity periodicity yielded a few latitudes with potential variability; the most significant periods were found nearly symmetrically about the equator at 0 deg., 10-12 deg. N, and 14-18 deg. S planetographic latitude. The low to mid-latitude signals have components consistent with the measured stratospheric temperature Quasi-Quadrennial Oscillation (QQO) period of-5 years, while the equatorial signal is approximately seasonal and could be tied to mesoscale wave formation, robustness tests indicate that a constant or continuously varying periodic signal near 4.5 years would appear with high significance in the data periodograms as long as uncertainties or noise in the data are not of greater magnitude. However, the lack of a consistent signal over many latitudes makes it difficult to interpret as a QQO-related change. In addition, further analyses of calibrated 410-nm and 953-nm brightness scans found few corresponding changes in troposphere haze and cloud structure on QQO timescales. However, stratospheric haze reflectance at 255-nm did appear to vary on seasonal timescales, though the data do not have enough temporal coverage or photometric accuracy to be conclusive. Sufficient temporal coverage and spacing, as well as data quality, are critical to this type of search.

  2. Habitability potential of satellites around Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Coustenis, Athena; Raulin, Francois; Encrenaz, Therese; Grasset, Olivier; Solomonidou, Anezina

    2016-07-01

    biomarkers. Currently, for Titan and Enceladus, geophysical models try to explain the possible existence of an oceanic layer that decouples the mantle from the icy crust. Titan has further been suggested to be a possible cryovolcanic world due to the presence of local complex volcanic-like geomorphology and the indications of surface albedo changes with time [7,8]. Such dynamic activity that would most probably include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. In one of our geophysical studies [4], we have showed that tidal forces are a constant and significant source of internal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of ammonia concentrations, thus completing the set of parameters needed for a truly habitable planetary body. If the silicate mantles of Europa and Ganymede and the liquid sources of Titan and Enceladus are geologically active as on Earth, giving rise to the equivalent of hydrothermal systems, the simultaneous presence of water, geodynamic interactions, chemical energy sources and a diversity of key chemical elements may fulfill the basic conditions for habitability. Such habitability indications from bodies at distances of 10 AU, are essential discoveries brought to us by space exploration and which have recently revolutionized our perception of habitability in the solar system. In the solar system's neighborhood, such potential habitats can only be investigated with appropriate designed space missions, like JUICE (JUpiter ICy moon Explorer) for Ganymede and Europa [9]. JUICE is an ESA mission to Jupiter and its icy moons, recently selected to launch in 2022. Other future mission concepts are being studied for exploring the moons around Saturn. References: [1] Coustenis, A., Encrenaz, Th., in "Life Beyond Earth

  3. Darkness on the Edge of Light: Stable Dark Spots in Jupiter's Ionosphere

    NASA Astrophysics Data System (ADS)

    Stallard, T.; Melin, H.; Miller, S.; O'Donoghue, J.; Johnson, R.

    2014-12-01

    We present the detection of dark regions in the jovian sub-auroral H3+ emission, first observed in recent December 2012 observations of Jupiter's aurora using CRIRES/VLT and confirmed to be stable on long timescales using a re-analysis of auroral images taken by J. Connerney and T. Satoh as a part of their 1995-2000 NSFCam/IRTF observations of the aurora.While the auroral region of Jupiter has been studied in great detail, the region equatorward of this has long been thought of as a gently gradated boundary region, with reduced emission towards Jupiter's equator. However, this new detection reveals what appears to be highly localised variable emission: dark regions with sharp boundaries and distinct shapes, offset from the auroral region. These dark features are broadly stable in both magnetic longitude and latitude over timescales of more than fifteen years, and yet vary in small-scale morphology over timescales of less than a month. This changing H3+ emission could represent the localised destruction of H3+, producing a reduction in H3+ density or, alternatively, a cooling of the co-located neutral atmosphere may be reducing the thermalised H3+ emission.However, what planetary process drives such changes is not clear. These unexplained features cannot be weather systems propagating from lower altitudes, as lower altitude weather systems generally drift along latitudinally bound bands, and these features are fixed in longitude over seasonal timescales. This strongly suggests a magnetospheric origin for the dimming. Perhaps the lack of emission is comparable to the 'Ring Rain' features seen in Saturn's equatorial regions. However, since these dark spots are confined to specific longitudes, unlike the bands of emission seen at Saturn, and their morphology appears to change with time, it is difficult to assign a magnetospheric source that would cause such a reduction in either H3+ density or temperature. Alternatively, the darkening may represent previously

  4. Waves from the collisions of comet Shoemaker-Levy 9 with Jupiter.

    PubMed

    Ingersoll, A P; Kanamori, H

    1995-04-20

    Observations of the collisions of the fragments of comet Shoemaker-Levy 9 with Jupiter provided an unprecedented opportunity to probe the depths of the planet's atmosphere. Images taken by the Hubble Space Telescope revealed circular rings surrounding five of the impact sites. The rings were observed for up to 2.5 hours after the impacts and spread at a constant velocity of 450 m s-1. There are three types of disturbance that might explain these observations: acoustic waves trapped at the tropopause temperature minimum, gravity waves propagating vertically and horizontally in the stratosphere, and gravity waves trapped in a stable layer which acts as a horizontal waveguide and is located within the hypothesized tropospheric water cloud. Here we show that only the last of these phenomena can match the speed and relative amplitude of the observed waves, with the requirement that the impacts were deep and the stability of the trapping layer is large. The origin of the stable layer is still uncertain, but if it is produced by moist convection in the water cloud, then the ratio of oxygen to hydrogen on Jupiter must be surprisingly large--approximately ten times that on the Sun.

  5. SPECTROSCOPIC EVIDENCE FOR A TEMPERATURE INVERSION IN THE DAYSIDE ATMOSPHERE OF HOT JUPITER WASP-33b

    SciTech Connect

    Haynes, Korey; Mandell, Avi M.; Madhusudhan, Nikku; Deming, Drake; Knutson, Heather

    2015-06-20

    We present observations of two occultations of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is the most highly irradiated hot Jupiter discovered to date, and the only exoplanet known to orbit a δ-Scuti star. We observed in spatial scan mode to decrease instrument systematic effects in the data, and removed fluctuations in the data due to stellar pulsations. The rms for our final, binned spectrum is 1.05 times the photon noise. We compare our final spectrum, along with previously published photometric data, to atmospheric models of WASP-33b spanning a wide range in temperature profiles and chemical compositions. We find that the data require models with an oxygen-rich chemical composition and a temperature profile that increases at high altitude. We find that our measured spectrum displays an excess in the measured flux toward short wavelengths that is best explained as emission from TiO. If confirmed by additional measurements at shorter wavelengths, this planet would become the first hot Jupiter with a thermal inversion that can be definitively attributed to the presence of TiO in its dayside atmosphere.

  6. Early Results from the Juno Mission at Jupiter

    NASA Astrophysics Data System (ADS)

    Bolton, Scott; Juno Science Team

    2016-10-01

    The Juno mission is the second mission in NASA's New Frontiers program. Launched in August 2011, Juno arrived at Jupiter July 4, 2016. Juno science goals include the study of Jupiter's origin, interior structure, deep atmosphere, aurora and magnetosphere. Juno's orbit around Jupiter is a polar elliptical orbit with perijove approximately 5000 km above the visible cloud tops. The payload consists of a set of microwave antennas for deep sounding, magnetometers, gravity radio science, low and high energy charged particle detectors, electric and magnetic field radio and plasma wave experiment, ultraviolet imaging spectrograph, infrared imager and a visible camera. Early results from the mission will be presented as well as an overview of planned observations.

  7. The galilean satellites and jupiter: voyager 2 imaging science results.

    PubMed

    Smith, B A; Soderblom, L A; Beebe, R; Boyce, J; Briggs, G; Carr, M; Collins, S A; Cook, A F; Danielson, G E; Davies, M E; Hunt, G E; Ingersoll, A; Johnson, T V; Masursky, H; McCauley, J; Morrison, D; Owen, T; Sagan, C; Shoemaker, E M; Strom, R; Suomi, V E; Veverka, J

    1979-11-23

    Voyager 2, during its encounter with the Jupiter system, provided images that both complement and supplement in important ways the Voyager 1 images. While many changes have been observed in Jupiter's visual appearance, few, yet significant, changes have been detected in the principal atmospheric currents. Jupiter's ring system is strongly forward scattering at visual wavelengths and consists of a narrow annulus of highest particle density, within which is a broader region in which the density is lower. On Io, changes are observed in eruptive activity, plume structure, and surface albedo patterns. Europa's surface retains little or no record of intense meteorite bombardment, but does reveal a complex and, as yet, little-understood system of overlapping bright and dark linear features. Ganymede is found to have at least one unit of heavily cratered terrain on a surface that otherwise suggests widespread tectonism. Except for two large ringed basins, Callisto's entire surface is heavily cratered.

  8. Plasma observations near jupiter: initial results from voyager 1.

    PubMed

    Bridge, H S; Belcher, J W; Lazarus, A J; Sullivan, J D; McNutt, R L; Bagenal, F; Scudder, J D; Sittler, E C; Siscoe, G L; Vasyliunas, V M; Goertz, C K; Yeates, C M

    1979-06-01

    Extensive measurements of low-energy positive ions and electrons were made throughout the Jupiter encounter of Voyager 1. The bow shock and magneto-pause were crossed several times at distances consistent with variations in the upstream solar wind pressure measured on Voyager 2. During the inbound pass, the number density increased by six orders of magnitude between the innermost magnetopause crossing at approximately 47 Jupiter radii and near closest approach at approximately 5 Jupiter radii; the plasma flow during this period was predominately in the direction of corotation. Marked increases in number density were observed twice per planetary rotation, near the magnetic equator. Jupiterward of the Io plasma torus, a cold, corotating plasma was observed and the energylcharge spectra show well-resolved, heavy-ion peaks at mass-to-charge ratios A/Z* = 8, 16, 32, and 64.

  9. Magnetic field studies at Jupiter by Voyager 2 - Preliminary results

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Acuna, M. H.; Lepping, R. P.; Burlaga, L. F.; Behannon, K. W.; Neubauer, F. M.

    1979-01-01

    The Voyager 2 magnetic field experiment, for which the instrumentation is identical to that on Voyager 1, operated flawlessly throughout the second Jupiter encounter. The paper presents a brief overview of the results obtained to date on the Jovian magnetosphere, the bow shock, the magnetopause, and the extended magnetic tail. The results and the magnetic field geometry confirm the earlier conclusion from Voyager 1 that Jupiter has an enormous magnetic tail, approximately 300-400 Jupiter radii in diameter, trailing behind the planet with respect to the supersonic flow of the solar wind. Additional observations of the distortion of the inner magnetosphere by a concentrated plasma show a spatial merging of the equatorial magnetodisk current with the current sheet in the magnetic tail. Disturbances near Ganymede are discussed.

  10. The galilean satellites and Jupiter: Voyager 2 imaging science results

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.A.; Beebe, R.; Boyce, J.; Briggs, G.; Carr, M.; Collins, S.A.; Cook, A.F.; Danielson, G.E.; Davies, M.E.; Hunt, G.E.; Ingersoll, A.; Johnson, T.V.; Masursky, H.; McCauley, J.; Morrison, D.; Owen, editors, Timothy W.; Sagan, C.; Shoemaker, E.M.; Strom, R.; Suomi, V.E.; Veverka, J.

    1979-01-01

    Voyager 2, during its encounter with the Jupiter system, provided images that both complement and supplement in important ways the Voyager 1 images. While many changes have been observed in Jupiter's visual appearance, few, yet significant, changes have been detected in the principal atmospheric currents. Jupiter's ring system is strongly forward scattering at visual wavelengths and consists of a narrow annulus of highest particle density, within which is a broader region in which the density is lower. On Io, changes are observed in eruptive activity, plume structure, and surface albedo patterns. Europa's surface retains little or no record of intense meteorite bombardment, but does reveal a complex and, as yet, little-understood system of overlapping bright and dark linear features. Ganymede is found to have at least one unit of heavily cratered terrain on a surface that otherwise suggests widespread tectonism. Except for two large ringed basins, Callisto's entire surface is heavily cratered. Copyright ?? 1979 AAAS.

  11. An Overview of the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Grammier, Richard S.

    2006-01-01

    Arriving in orbit around the planet Jupiter in 2016 after a five-year journey, the Juno spacecraft will begin a one-year investigation of the gas giant in order to understand its origin and evolution by determining its water abundance and constraining its core mass. In addition, Juno will map the planet's magnetic and gravitational fields, map its atmosphere, and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras. Juno will discriminate among different models for giant planet formation. These investigations will be conducted over the course of thirty-two 11-day elliptical polar orbits of the planet. The orbits are designed to avoid Jupiter's highest radiation regions. The spacecraft is a spinning, solar-powered system carrying a complement of eight science instruments for conducting the investigations. The spacecraft systems and instruments take advantage of significant design and operational heritage from previous space missions.

  12. In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter H.; Laughlin, Gregory P.

    2016-10-01

    Hot Jupiters, giant extrasolar planets with orbital periods shorter than ˜10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we offer the contrasting view that a substantial fraction of the hot Jupiter population formed in situ via the core-accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by super-Earth-type planets, comprising 10-20 Earth masses of refractory material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ˜100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems’ lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  13. Comparison of magnetospheres and radio emissions of Jupiter with earth

    NASA Technical Reports Server (NTRS)

    Libby, L. M.; Libby, W. F.

    1975-01-01

    The magnetosphere and radio emission of Jupiter is compared with those of the earth. It was predicted that Jupiter would have a Van Allen belt at a radius such that its magnetic field strength would be about equal to that in earth's Van Allen belt and that Jupiter's moon Io travels in the Van Allen belt. Because of Io's low conductivity, plasma sweeping past hits Io, producing a turbulent plasma proboscis which forms hydrodynamic shocks. These shocks travel down the magnetic field lines to the Jovian magnetosphere where they stimulate electron cyclotron emission and free radical spin-flip emission. The free radicals likely to exist abundantly and the richness of the likely decametric frequencies resulting from the many g values of the free radicals are discussed.

  14. WASP-47: a Hot Jupiter with Close Friends

    NASA Astrophysics Data System (ADS)

    Becker, Juliette; Adams, Fred C.

    2016-05-01

    WASP-47 was observed in Campaign 5 of the extended Kepler mission, K2. We report the discovery of two nearby planetary companions in this system, with periods of roughly 0.8 days and 9 days, respectively. This system is the first (and, at the date of writing this abstract, only) hot Jupiter to be found to have such nearby companions, one of which was detectable through the transit timing variations of the hot Jupiter. Using the K2 photometry and the results of several follow-up measurements, we will discuss the architecture of this intriguing system and the implications its detection has on our understanding of the formation and migration of hot Jupiters.

  15. Galileo's first images of Jupiter and the Galilean satellites

    USGS Publications Warehouse

    Belton, M.J.S.; Head, J. W.; Ingersoll, A.P.; Greeley, R.; McEwen, A.S.; Klaasen, K.P.; Senske, D.; Pappalardo, R.; Collins, G.; Vasavada, A.R.; Sullivan, R.; Simonelli, D.; Geissler, P.; Carr, M.H.; Davies, M.E.; Veverka, J.; Gierasch, P.J.; Banfield, D.; Bell, M.; Chapman, C.R.; Anger, C.; Greenberg, R.; Neukum, G.; Pilcher, C.B.; Beebe, R.F.; Burns, J.A.; Fanale, F.; Ip, W.; Johnson, T.V.; Morrison, D.; Moore, J.; Orton, G.S.; Thomas, P.; West, R.A.

    1996-01-01

    The first images of Jupiter, Io, Europa, and Ganymede from the Galileo spacecraft reveal new information about Jupiter's Great Red Spot (GRS) and the surfaces of the Galilean satellites. Features similar to clusters of thunderstorms were found in the GRS. Nearby wave structures suggest that the GRS may be a shallow atmospheric feature. Changes in surface color and plume distribution indicate differences in resurfacing processes near hot spots on lo. Patchy emissions were seen while Io was in eclipse by Jupiter. The outer margins of prominent linear markings (triple bands) on Europa are diffuse, suggesting that material has been vented from fractures. Numerous small circular craters indicate localized areas of relatively old surface. Pervasive brittle deformation of an ice layer appears to have formed grooves on Ganymede. Dark terrain unexpectedly shows distinctive albedo variations to the limit of resolution.

  16. Jupiter: Atmospheric Sounding and Sensing of the Interior (JASSI)

    NASA Technical Reports Server (NTRS)

    Bolton, S. J.; Owen, T.; Gautier, D.; Gulkis, S.; Janssen, M.; Atreya, S.; Guillot, T.; Anderson, J.; Allison, M.; Lunine, J.

    2001-01-01

    The formation of the giant planets is one of the most fundamental questions in solar system exploration. Understanding the process that led to the creation of Jupiter is essential to understanding the nature of the primordial solar nebula, and the formation of our solar system and others currently being discovered. Data from Galileo combined with HST and Ulysses results validated our basic understanding of Jupiter as a giant planet whose gaseous envelope consists of solar nebula gas enriched in elements heavier than He by in falling icy planetesimals. However, the current Galileo Probe data set does not itself allow firm conclusions about the original planetesimal composition or the process of giant planet formation - we crucially need the O and N abundances that Galileo could not determine. We propose a new and simple concept capable of determining these abundance in Jupiter plus substantial gravity science. Additional information is contained in the original extended abstract.

  17. Chemical models of the deep atmospheres of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.; Lodders, Katharina

    1994-01-01

    New and updated chemical kinetic data, elemental abundances, and thermodynamic data are used for thermochemical equilibrium and, where relevant, thermochemical kinetic calculations of gas abundances and condensate stability in the hot, deep atmospheres of Jupiter and Saturn. Over 2000 compounds of all naturally occurring elements in the periodic table are considered. The calculations range from 298 to 2000 K and are done for adiabatic models of the two planetary atmospheres. The results predict the abundances of many gases which are potentially observable by the Galileo probe to Jupiter, by the Cassini mission to Saturn, and by Earth-based and Earth-orbital telescopes. In addition, the results also predict many new species which are potentially observable by a new generation of entry probes capable of penetrating deeper into the atmospheres of Jupiter and Saturn.

  18. Planar Close Encounter Trajectories for Spacecrafts Passing Near Jupiter

    NASA Astrophysics Data System (ADS)

    Prado, A. F.; Broucke, R. A.

    In the present paper we study and classify Swing-By trajectories that use the planet Jupiter as the body for the close approach. The goal is to simulate a complete set of initial conditions for those orbits and classify them according to the effects caused by the close approach with Jupiter on the orbit of the spacecraft. The well-known planar restricted circular three-body problem is used as the mathematical model. The equations are regularized (using Lemaître's regularization), so it is possible to avoid the numerical problems that come from the close approach with Jupiter. After that, the velocity increment required to start or to stop the spacecraft at the Earth and the flight path angle at the meeting point are calculated. A section is also written to compare the results obtained with the dynamics given by the restricted problem and the "patched-conics" approximation. It is especially checked which ones of those orbits have a passage near the Earth in the outbound (starting at the Earth) and in the inbound (starting at Jupiter) trajectories. This is very important, because those orbits have more chances of practical application. The outbound trajectories are useful to send a spacecraft to Jupiter and the inbound trajectories are important because an asteroid passing by Jupiter may follow this trajectory to collide with the Earth. The results are shown in plots where one letter describing the effects of the Swing-by is assigned to the respective area in a two-dimensional graph that has in the horizontal axis the angle Psi (the approach angle) and in the vertical axis the Jacobian constant of the spacecraft. There is one plot for each value of the parameter Rp. After that, the velocity change required to start or to stop the spacecraft at the Earth and the flight path angle at the meeting point are calculated.

  19. Carbon monoxide and disequilibrium dynamics in Saturn and Jupiter

    SciTech Connect

    Noll, K.S.

    1987-01-01

    High resolution ({sup {xi}}/{sub {Delta}{xi}} {approximately} 30,000) spectra of Jupiter and Saturn were obtained in order to study the composition and dynamics of Jupiter and Saturn. The shapes of CO absorption lines in Jupiter are broad, consistent with line formation at P {approximately} 2-9 bars. This is strong evidence in favor of internal mixing as the source of CO in Jupiter. Further, we find that the O abundance at 1100 K must be nearly solar. No variations in CO abundance were found between the North Equatorial Belt, the North Tropical Zone, and the Great Red Spot. Because CO is very sensitive to variations in the rate of mixing, we conclude that there are no gross variations in mixing with location on Jupiter. We observed CO in Saturn for the first time. The source of CO in Saturn is uncertain, although theoretical arguments favor an external source to an internal one. If Saturn's rings are the source of the oxygen that eventually leads to CO in Saturn, the rate of influx required imposes an upper limit to the lifetime of the rings of t < 100 million years. We have also found the first evidence for GeH{sub 4} in the atmosphere of Saturn. Absorption lines in the P and R branch of GeH{sub 4} are observed although no evidence of the stronger Q branch is found. We postulate that scattered solar radiation may be responsible for altering the thermal spectrum in regions of very low flux such as the Q branch region. The abundance of GeH{sub 4} is consistent with the expected disequilibration from internal mixing in Saturn. Finally, we found more acetylene in the stratosphere of Saturn as compared to Jupiter, indicating possibly faster mixing in Saturn's upper atmosphere.

  20. JUpiter ICy moons Explorer (juice): AN ESA L-Class Mission Candidate to the Jupiter System

    NASA Astrophysics Data System (ADS)

    Dougherty, M. K.; Grasset, O.; Erd, C.; Titov, D.; Bunce, E. J.; Coustenis, A.; Blanc, M.; Coates, A. J.; Drossart, P.; Fletcher, L.; Hussmann, H.; Jaumann, R.; Krupp, N.; Prieto-Ballesteros, O.; Tortora, P.; Tosi, F.; Van Hoolst, T.

    2012-04-01

    the first subsurface observations of this icy moon, including the first determination of the minimal thickness of the icy crust over the most recently active regions. JUICE will determine the characteristics of liquid-water oceans below the icy surfaces of the moons. This will lead to an understanding of the possible sources and cycling of chemical and thermal energy, allow investigation of the evolution and chemical composition of the surfaces and of the subsurface oceans, and enable an evaluation of the processes that have affected the satellites and their environments through time. The study of the diversity of the satellite system will be enhanced with additional information gathered remotely on Io and smaller moons. The mis-sion will also focus on characterising the diversity of processes in the Jupiter system which may be required in order to provide a stable environment at Ganymede, Europa and Callisto on geologic time scales, including gravitational coupling between the Galilean satellites and their long term tidal influence on the system as a whole. Focused stud-ies of Jupiter's atmosphere, and magnetosphere and their interaction with the Galilean satellites will further enhance our understanding of the evolution and dynamics of the Jovian system. The circulation, meteorology, chemistry and structure of Jupiter will be studied from the cloud tops to the thermosphere. These observations will be attained over a sufficiently long temporal baseline with broad latitudinal coverage to investigate evolving weather systems and the mechanisms of transporting energy, momentum and material between the different layers. The focus in Jupiter's magnetosphere will include an investigation of the three dimensional properties of the magnetodisc and in-depth study of the coupling processes within the magnetosphere, ionosphere and thermosphere. Aurora and radio emissions and their response to the solar wind will be elucidated.

  1. Planets of the solar system. [Jupiter and Venus

    NASA Technical Reports Server (NTRS)

    Kondratyev, K. Y.; Moskalenko, N. I.

    1978-01-01

    Venera and Mariner spacecraft and ground based radio astronomy and spectroscopic observations of the atmosphere and surface of venus are examined. The composition and structural parameters of the atmosphere are discussed as the basis for development of models and theories of the vertical structure of the atmosphere, the greenhouse effect, atmospheric circulation and cloud cover. Recommendations for further meteorological studies are given. Ground based and Pioneer satellite observation data on Jupiter are explored as well as calculations and models of the cloud structure, atmospheric circulation and thermal emission field of Jupiter.

  2. Radiosounding of Jupiters Atmosphere with EJSM-Laplace

    NASA Astrophysics Data System (ADS)

    Pätzold, M.; Andert, T.; Häusler, B.; Keil, W.; Mai, W.; Schäfer, W.; Schwall, T.; Tellmann, S.; Tyler, G. L.

    2011-10-01

    The feasibility and performance of a radio science experiment on EJSM-Laplace for the sounding of Jupiters atmosphere and ionosphere (occultation experiment) has been studied. The experiment intends to use two downlink frequencies provided by the spacecraft radio subsystem and stabilized by an Ultrastable Oscillator (USO). Opportunities and performance based on the technical provisions and the baseline orbit will be shown. Solutions have been developed for the the hardening and shielding of the USO versus the harsh radiation in Jupiters environment. As an option or alternative an uplink experiment has been studied in parallel which may be of advantage for certain constellations.

  3. Planar close encounter trajectories for spacecrafts passing near Jupiter

    NASA Astrophysics Data System (ADS)

    de Almeida Prado, Antonio Fernando Bertachini; Broucke, Roger A.

    In this research, we study trajectories that make a close approach with the planet Jupiter. The main goal is to obtain the velocity increments required to start or to stop the spacecraft at the Earth and the flight path angle at the meeting point for trajectories that cross the Earth's orbit around the Sun before or after the passage by Jupiter. The regularized planar restricted circular three-body problem is used as the mathematical model. Several trajectories are found and shown in detail, including the impulses required for those maneuvers.

  4. Cassini imaging of Jupiter's atmosphere, satellites, and rings.

    PubMed

    Porco, Carolyn C; West, Robert A; McEwen, Alfred; Del Genio, Anthony D; Ingersoll, Andrew P; Thomas, Peter; Squyres, Steve; Dones, Luke; Murray, Carl D; Johnson, Torrence V; Burns, Joseph A; Brahic, Andre; Neukum, Gerhard; Veverka, Joseph; Barbara, John M; Denk, Tilmann; Evans, Michael; Ferrier, Joseph J; Geissler, Paul; Helfenstein, Paul; Roatsch, Thomas; Throop, Henry; Tiscareno, Matthew; Vasavada, Ashwin R

    2003-03-01

    The Cassini Imaging Science Subsystem acquired about 26,000 images of the Jupiter system as the spacecraft encountered the giant planet en route to Saturn. We report findings on Jupiter's zonal winds, convective storms, low-latitude upper troposphere, polar stratosphere, and northern aurora. We also describe previously unseen emissions arising from Io and Europa in eclipse, a giant volcanic plume over Io's north pole, disk-resolved images of the satellite Himalia, circumstantial evidence for a causal relation between the satellites Metis and Adrastea and the main jovian ring, and information on the nature of the ring particles. PMID:12624258

  5. Recent Simulations of the Late Stages Growth of Jupiter

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; D'Angelo, Gennaro; Hubickyj, Olenka

    2012-01-01

    Presented by Lissauer et al. (2009, Icarus 199, 338) are used to test the model of capture of Jupiter's irregular satellites within proto-Jupiter's distended and thermally-supported envelope. We find such capture highly unlikely, since the envelope shrinks too slowly for a large number of moons to be retained, and many of those that would be retained would orbit closer to the planet than do the observed Jovian irregulars. Our calculations do not address (and therefore do not exclude) the possibility that the irregular satellites were captured as a result of gas drag within a circumjovian disk. Support for this research from NASA Outer Planets Research Program is gratefully acknowledged.

  6. Launch Period Development for the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Kowalkowski, Theresa D.; Johannesen, Jennie R.; Lam, Try

    2008-01-01

    The Juno mission to Jupiter is targeted to launch in 2011 and would reach the giant planet about five years later. The interplanetary trajectory is planned to include two large deep space maneuvers and an Earth gravity assist a little more than two years after launch. In this paper, we describe the development of a 21-day launch period for Juno with the objective of keeping overall launch energy and delta-V low while meeting constraints imposed on Earth departure, the deep space maneuvers' timing and geometry, and Jupiter arrival.

  7. THE JOINT ESA-NASA EUROPA JUPITER SYSTEM MISSION (EJSM)

    NASA Astrophysics Data System (ADS)

    Lebreton, J.; Pappalardo, R. T.; Blanc, M.; Bunce, E. J.; Dougherty, M. K.; Erd, C.; Grasset, O.; Greeley, R.; Johnson, T. V.; Clark, K. B.; Prockter, L. M.; Senske, D. A.

    2009-12-01

    The joint "Europa Jupiter System Mission" (EJSM) is an international mission under study in collaboration between NASA and ESA. Its goal is to study Jupiter and its magnetosphere, the diversity of the Galilean satellites, the physical characteristics, composition and geology of their surfaces. Europa and Ganymede are two primary targets of the mission. The reference mission architecture consists of the NASA-led Jupiter Europa Orbiter (JEO) and the ESA-led Jupiter Ganymede Orbiter (JGO). The two primary goals of the mission are i) to determine whether the Jupiter system harbors habitable worlds and ii) to characterize the processes within the Jupiter system. The science objectives addressing the first goal are to: i) characterize and determine the extent of subsurface oceans and their relations to the deeper interior, ii) characterize the ice shells and any subsurface water, including the heterogeneity of the ice, and the nature of surface-ice-ocean exchange; iii) characterize the deep internal structure, differentiation history, and (for Ganymede) the intrinsic magnetic field; iv) compare the exospheres, plasma environments, and magnetospheric interactions; v) determine global surface composition and chemistry, especially as related to habitability; vi) understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future in situ exploration. The science objectives for addressing the second goal are to: i) understand the Jovian satellite system, especially as context for Europa and Ganymede; ii) evaluate the structure and dynamics of the Jovian atmosphere; iii) characterize processes of the Jovian magnetodisk/magnetosphere; iv) determine the interactions occurring in the Jovian system; and v) constrain models for the origin of the Jupiter system. Both spacecraft would carry a complement of 11-12 instruments launch separately in 2020 and use a Venus-Earth-Earth Gravity Assist (VEEGA

  8. Differential rotation in Jupiter: A comparison of methods

    NASA Astrophysics Data System (ADS)

    Wisdom, J.; Hubbard, W. B.

    2016-03-01

    Whether Jupiter rotates as a solid body or has some element of differential rotation along concentric cylinders is unknown. But Jupiter's zonal wind is not north/south symmetric so at most some average of the north/south zonal winds could be an expression of cylinders. Here we explore the signature in the gravitational moments of such a smooth differential rotation. We carry out this investigation with two general methods for solving for the interior structure of a differentially rotating planet: the CMS method of Hubbard (Hubbard, W.B. [2013]. Astrophys. J. 768, 1-8) and the CLC method of Wisdom (Wisdom, J. [1996]. Non-Perturbative Hydrostatic Equilibrium.

  9. Ultraviolet Studies of Jupiter's Hydrocarbons and Aerosols from Galileo

    NASA Technical Reports Server (NTRS)

    Gladstone, G. Randall

    2001-01-01

    This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the variability of the auroral emissions rather than the absorption signatures of hydrocarbons, although we have done some work in this area with related HST-STIS data.

  10. Cassini imaging of Jupiter's atmosphere, satellites, and rings.

    PubMed

    Porco, Carolyn C; West, Robert A; McEwen, Alfred; Del Genio, Anthony D; Ingersoll, Andrew P; Thomas, Peter; Squyres, Steve; Dones, Luke; Murray, Carl D; Johnson, Torrence V; Burns, Joseph A; Brahic, Andre; Neukum, Gerhard; Veverka, Joseph; Barbara, John M; Denk, Tilmann; Evans, Michael; Ferrier, Joseph J; Geissler, Paul; Helfenstein, Paul; Roatsch, Thomas; Throop, Henry; Tiscareno, Matthew; Vasavada, Ashwin R

    2003-03-01

    The Cassini Imaging Science Subsystem acquired about 26,000 images of the Jupiter system as the spacecraft encountered the giant planet en route to Saturn. We report findings on Jupiter's zonal winds, convective storms, low-latitude upper troposphere, polar stratosphere, and northern aurora. We also describe previously unseen emissions arising from Io and Europa in eclipse, a giant volcanic plume over Io's north pole, disk-resolved images of the satellite Himalia, circumstantial evidence for a causal relation between the satellites Metis and Adrastea and the main jovian ring, and information on the nature of the ring particles.

  11. Vibrationally excited molecular hydrogen in the upper atmosphere of Jupiter

    NASA Astrophysics Data System (ADS)

    Cravens, T. E.

    1987-10-01

    Experiments on the Voyager 1 and 2 spacecraft and observations made by the International Ultraviolet Explorer (IUE) have provided evidence for the existence of energetic particle precipitation into the upper atmosphere of Jupiter from the magnetosphere. This auroral precipitation has been shown to generate large ionization and dissociation rates, to excite auroral emissions, and also to vibrationally excite molecular hydrogen. A theoretical model of vibrationally excited H2 in the upper atmosphere of Jupiter is presented in this paper. Models are considered for both the auroral region and also for lower latitudes, where H2 is vibrationally excited owing to processes associated with the absorption of solar ultraviolet radiation.

  12. Evaluation of Jupiter longitudes in System III/1965/

    NASA Technical Reports Server (NTRS)

    Seidelmann, P. K.; Divine, N.

    1977-01-01

    Commission 40 of the International Astronomical Union has adopted a new longitude system for Jupiter, labelled System III(1965), to replace the provisional System III(1957.0). The specification of the prime meridian and epoch for the new system differs slightly from that recently published. Its rotation rate implies a period of 9 hr 55 min 29.711 (plus or minus 0.04) sec, consistent with recent determinations from decimetric and decametric data. For both the new and older systems, equations are provided which are useful in the evaluation of longitudes for the analysis of Jupiter radio, particle, and field data from earth and spacecraft observations.

  13. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... Order No. 7202 (61 FR 29758 (1996)), which reserved public land on Jupiter Inlet, Florida, for... Bureau of Land Management Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse... Management to continue to be managed as part of the Jupiter Inlet Lighthouse Outstanding Natural Area....

  14. Temporally Varying Ethylene Emission on Jupiter

    NASA Technical Reports Server (NTRS)

    Romani, Paul N.; Jennings, Donald E.; Bjoraker, Gordon L.; Sada, Pedro V.; McCabe. Geprge; Boyle, Robert J.

    2008-01-01

    Ethylene (C2H4) emission has been measured in the poles and equator of Jupiter. The 949 cm(sup -1) spectra were recorded with a high resolution spectrometer at the McMath-Pierce telescope at Kitt Peak in October-November 1998 and at the Infrared Telescope Facility at Mauna Kea in June 2000. C2H4 is an important product of methane chemistry in the outer planets. Knowledge of its abundance can help discriminate among the various proposed sets of CH4 photolysis branching ratios at Ly-alpha, and determine the relative importance of the reaction pathways that produce C2H2 and C2H6. In the equatorial region the C2H4 emission is weak, and we were only able to detect it at high air-mass, near the limb. We derive a peak equatorial molar abundance of C2H4 of 4.5 x 10(exp -7) - 1.7 x 10(exp -6) near 2.2 x 10(exp -3) mbar, with a total column of 5.7 x 10(exp 14) - 2.2 x 10(exp 15) molecules cm(exp -2) above 10 mbar depending upon choice of thermal profile. We observed enhanced C2H4 emission from the poles in the regions where auroras are seen in X-ray, UV, and near infrared images. In 2000 we measured a short-term change in the distribution of polar C2H4 emission; the emission in the north IR auroral "hot spot" decreased by a factor of three over a two-day interval. This transient its contribution peak at 5-10 microbar suggests that the polar e is primarily a thermal effect coupled with vertical transport. Comparing our observations from Kitt Peak and Mauna Kea shows that the C2H4 emission of the northern non-"hot spot" auroral regions did not change over the three-year period while that in the southern polar regions decreased.

  15. Making Space Travel to Jupiter Possible

    NASA Technical Reports Server (NTRS)

    Barker, Samuel P.

    2004-01-01

    From man landing on the moon to a simple satellite being launched into orbit, many incredible space accomplishments have been witnessed by us all. However, what goes un-noticed to the common man is the extensive research and testing that lasts months, years, and even decades. Much of this required research just so happens to take place in the corridors of the Glen Research Center building number 49. In the Advanced Materials division of G.R.C., a number of researchers have the responsibility of discovering which metal, ceramic, or polymer is best for a specific application. Under the guidance of mentor extraordinaire Frank Ritzert, I am involved in many critical projects dealing with refractory metals, two of which I will mention in this report. The Jupiter Icy Moons Orbiter (JIMO) project actually was under full swing back in the 50's and early 60's. To enable the 14 year trek to the icy moons of Europa, Callisto, and Ganymede, nuclear propulsion methods were selected. Due to the extreme temperature of the reactor and the extended time period, a refractory metal would need to be implemented. After years of research and progress, the program was suddenly canceled. About a decade ago, the JIMO project was re-instated and now has a goal for departure around 2014. However, a few obstacles lie in our way concerning the use of refractory metals. In certain areas of the orbiter a joint is required between the refractories and other less dense metals. Two of these joints are with nickel based super alloys. Being an intern for Frank Ritzert, the refractory metals expert, I have the opportunity to develop the best method to braze refractory metals to Nickel 201. This involves the actual brazing, electron microscopy and reporting the results. My second project involves a certain part of the orbiter where Niobium 1Zirconium, a refractory metal, is joined with Hastelloy-X a Ni based metal. Small quantities of oxygen, helium and other impurities in the Ni alloy could diffuse

  16. Explosions of infalling comets in Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Chevalier, Roger A.; Sarazin, Craig L.

    1994-01-01

    In view of the expected collision of comet Shoemaker-Levy 9 (1993e) with Jupiter in 1994 July, we calculate basic properties of the initial interaction for a simplified Jovian atmosphere. The comet is expected to impact Jupiter at 60 km/sec and at an angle of 45 deg to the zenith. The shock wave generated by the bolide should be optically thick once it has penetrated to an atmospheric density approximately 10(exp -6) gr/cm(exp 3), and we calculate the post-shock conditions assuming local thermodynamic equilibrium (LTE) for shock velocities v(sub sh) in the range 10 to 60 km/sec and preshock densities rho(sub a) = 10(exp -6) to 10(exp -2) gr/cm(exp 3). Our shock calculations include molecular hydrogen, atomic hydrogen, ionized hydrogen, neutral helium, and singly ionized helium. Even at the highest shock velocity, the gas is only partially ionized and the postshock temperature rises with preshock density in order to maintain the ionization. The value of the effective shock adiabatic index gamma(sub sh) varies from 1.17 (at low v(sub sh) and rho(sub a) to 1.40 (at high v(sub sh) and rho(sub a). The ablation rate is limited by the radiative flux that reaches the bolide surface. We argue that the ablated gas does not efficiently transfer its kinetic energy to the atmosphere, and it ultimately slows in a similar fashion to the comet material. As the bolide initially falls through the atmosphere, the character of the shock emission changes. At rho(sub a) approximately 10(exp -8) gr/cm (exp 3), the gas is optically thin and we expect line emission; in the optical spectrum, Balmer emission is expected from the shocked atmosphere and low-ionization metal lines from ablated cometary material. At rho(sub a) approximately 10(exp -6) gr/m(exp 3), the shocked gas is optically thick and the shock front near the bolide produces a blackbody spectrum. The temperature is favorable for ultraviolet (1000 to 3000 A) emission and the luminosity may be approximately 5 x 10(exp 23) ergs

  17. 3D Modeling of Spectra and Light Curves of Hot Jupiters with PHOENIX; a First Approach

    NASA Astrophysics Data System (ADS)

    Jiménez-Torres, J. J.

    2016-04-01

    A detailed global circulation model was used to feed the PHOENIX code and calculate 3D spectra and light curves of hot Jupiters. Cloud free and dusty radiative fluxes for the planet HD179949b were modeled to show differences between them. The PHOENIX simulations can explain the broad features of the observed 8 μm light curves, including the fact that the planet-star flux ratio peaks before the secondary eclipse. The PHOENIX reflection spectrum matches the Spitzer secondary-eclipse depth at 3.6 μm and underpredicts eclipse depths at 4.5, 5.8 and 8.0 μm. These discrepancies result from the chemical composition and suggest the incorporation of different metallicities in future studies.

  18. Possible radio wave precursors associated with the comet Shoemaker-Levy 9/Jupiter impacts

    NASA Technical Reports Server (NTRS)

    Farrell, W. M.; Kaiser, M. L.; Desch, M. D.; Macdowall, R. J.

    1994-01-01

    We suggest that prior to its impact with Jupiter, comet Shoemaker-Levy 9 will behave as an electrical generator in the Jovian magnetosphere, converting planetary rotational energy to electrical energy via a dust/plasma interaction. This electrical energy will then be deposited in the dayside auroral region where it may drive various auroral phenomena including cyclotron radio emission. Such emission could be detected by spacecraft like Ulysses and Galileo many hours prior to the actual comet impact with the upper atmosphere. We apply the theory originally developed to explain the spokes in Saturn's rings. This theory allows us to quantify the driving potential associated with the comet and, consequently, to determine the radio power created in the auroral region. We conclude that if enough fine dust is present in the cometary system, comet-induced auroral radio emissions will reach detectable levels. This emission should be observable in the dayside hemisphere about 12-24 hours prior to each fragment impact.

  19. Jupiter Data Analysis Program: Analysis of Voyager wideband plasma wave observations

    NASA Technical Reports Server (NTRS)

    Kurth, W. S.

    1983-01-01

    Voyager plasma wave wideband frames from the Jovian encounters are analyzed. The 511 frames which were analyzed were chosen on the basis of low-rate spectrum analyzer data from the plasma wave receiver. These frames were obtained in regions and during times of various types of plasma or radio wave activity as determined by the low-rate, low-resolution data and were processed in order to provide high resolution measurements of the plasma wave spectrum for use in the study of a number of outstanding problems. Chorus emissions at Jupiter were analyzed. The detailed temporal and spectral form of the very complex chorus emissions near L = 8 on the Voyager 1 inbound passage was compared to both terrestrial chorus emissions as well as to the theory which was developed to explain the terrestrial waves.

  20. An Overview of the Jupiter Europa Orbiter Concept's Europa Science Phase Orbit Design

    NASA Technical Reports Server (NTRS)

    Lock, Robert E.; Ludwinski, Jan M.; Petropoulos, Anastassios E.; Clark, Karla B.; Pappalardo, Robert T.

    2009-01-01

    Jupiter Europa Orbiter (JEO), the proposed NASA element of the proposed joint NASA-ESA Europa Jupiter System Mission (EJSM), could launch in February 2020 and conceivably arrive at Jupiter in December of 2025. The concept is to perform a multi-year study of Europa and the Jupiter system, including 30 months of Jupiter system science and a comprehensive Europa orbit phase of 9 months. This paper provides an overview of the JEO concept and describes the Europa Science phase orbit design and the related science priorities, model pay-load and operations scenarios needed to conduct the Europa Science phase. This overview is for planning and discussion purposes only.