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Sample records for krievs leonids ribickis

  1. 2001 Leonid Meteoroid Storm

    DTIC Science & Technology

    2007-11-02

    and discuss their possible consequences and mitigation strategies. 15. SUBJECT TERMS Meteors , Leonids, Meteoroids, Spacecraft, Meteor showers , Impact...release; distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT We present the latest predictions about the November 2001 Leonid Meteor storms

  2. 1997 Leonid Shower from Space

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter; Nugent, David; Tedesco, Ed; Murthy, Jayant

    In November 1997, the Midcourse Space Experiment satellite (MSX) was deployed to observe the Leonid shower from space. The shower lived up to expectations, with abundant bright fireballs. Twenty-nine meteors were detected by a wide-angle, visible wavelength, camera near the limb of the Earth in a 48-minute interval, and three meteors by the narrow field camera. This amounts to a meteoroid influx of 5.5 +/- 0.6 10^-5 km^-2 hr^-1 for masses > 0.3 gram. The limiting magnitude for limb observations of Leonid meteors was measured at M_v = -1.5 magn. The Leonid shower magnitude population index was 1.6 +/- 0.2 down to M_v = -7 magn., with no sign of an upper mass cut-off.

  3. Assessing Leonid Meteoroid Impact Risks

    NASA Astrophysics Data System (ADS)

    Lee, Aleck L.

    2000-10-01

    The Leonid meteoroid storm produced by the passage of its parent comet, 55p/Tempel-Tuttle has been a concern for satellite operators. The recent close approach of the comet to the Earth took place around January 17, 1998. The debris cloud was expected to be several hundred to several thousand times higher than normal in the ensuing years when the Earth passes by the comet trail. Leonid meteoroid storm intensity was predicted before by analyses for satellite mission planning. The low observed Zenith Hourly Rate (ZHR) displayed in 1998 was due to the large distance between the particle and the Earth. In 1998, all of the Leonid material was located interior to the Earth's orbit at distances greater than 0.004 AU. In 1999 there will be two streams located interior to the Earth orbit; the first, consisting of material ejected from the comet in 1932, will be 0.0016 AU from the Earth, and the second composed of material ejected from Tempel-Tuttle in 1965 at 0.004 AU. More importantly, there will exist a third stream of cometary debris, located just 0.0008 AU exterior to Earth's orbit. This stream will consist of the material ejected in 1899, and its close proximity to the Earth means that the space shall be subjected to a Gaussian-like Leonid environment. The predicted probability indicates that there will certainly be a storm with ZHR higher than 1000 in November 1999. It is also likely that there will be another Leonid storm in 2000. A procedure to predict the number of hits by the meteoroids was developed using the ZHR prediction model and the orbit data of GEO communication satellites. The data include the attitude of the satellite and its projected area as a function of orbit position. The number and probability of hits are predicted for these satellites during the 1999 Leonid meteoroid storm. The worst case prediction is also included for comparison.

  4. Leonid meteors, 2001 November 18

    NASA Astrophysics Data System (ADS)

    McGee, H. W.; Mobberley, M. P.

    2002-02-01

    Leonid meteors photographed from Palau, Micronesia, on 2001 November 18. Clockwise from top right: 3 meteors in Corvus, 19.18-19.20 UT; brilliant fireball in Orion, 18.48.30 UT; bright Leonid in Hydra, 19.06 UT. 50mm f/1.8 lens, 1600 ISO Fuji Superia film; M.P. Mobberley. Top left: Composite of three 5-minute exposures between 19.15 and 19.36 UT. 28mm f2.8 lens, 800 ISO Kodak Gold film; H.W. McGee.

  5. Discovery of Leonid Meteoric Cloud

    DTIC Science & Technology

    2007-11-02

    as a local enhancement in sky brightness during the meteor shower in 1998. The radius of the trail, deduced from the spatial extent of the cloud, is...A meteoric cloud is a faint glow of sunlight scattered by the small meteoroids in the trail along a parent comets orbit. Here we report the first...detection of the meteoric cloud associated with the Leonid meteor stream. Our photometric observations, performed on Mauna Kea, Hawaii, reveal the cloud

  6. The Leonid storms of 2003

    NASA Astrophysics Data System (ADS)

    Bone, N.

    2003-02-01

    As they have done in the past several years, the Leonids attracted a lot of interest in 2003 following the forecast by Robert McNaught and David Asher, among others, of further outbursts of enhanced activity close to November 19d 04h 00m and 19d 10h 30m UT. Storm-level activity seen in 2001 at previous encounters with the same debris trails (ejected from comet 55P/Tempel(Tuttle in 1799 and 1866 respectively) heightened the expectation that good activity would ensue in 2003.

  7. Photographic Leonids 1998 Observed at Modra Observatory

    NASA Astrophysics Data System (ADS)

    Tóth, Juraj; Kornoš, Leonard; Porubčan, Vladimir

    Results of photographic observations of the 1998 Leonids performed at Modra Observatory (Slovakia) are presented and discussed. During an exposure time of 7 hr 14 min on November 16/17 a total of 168 meteors were recorded. Photographic rates of bright Leonid meteors as well as their magnitude distribution are presented and compared with the results obtained by other techniques. The photographic 1998 Leonids exhibit a maximum at the solar longitude 234.52°, Equinox 2000.0 (Nov. 17, 01:40 UT).

  8. Leonids: Did They Make it to Earth?

    NASA Technical Reports Server (NTRS)

    Weigel, A.; Lepland, A.; De, Sasadhar; Marti, K.; Arrhenius, G.

    2000-01-01

    On the morning of November 18. 1998, following the spectacular Leonid meteor shower, one of us (S. De) found particles spread over the roof terrace in a residence in Baruipur. a suburb of Calcutta, India. Considering the time and location, these particles possibly derived from the meteor shower, although the fall was not observed. Other particles collected in connection with the Leonid showers in different parts of India proved to be of terrestrial origin.

  9. Search for Organic Matter in Leonid Meteoroids

    NASA Astrophysics Data System (ADS)

    Rairden, Richard L.; Jenniskens, Peter; Laux, Christophe O.

    Near-ultraviolet 300-410 nm spectra of Leonid meteoroids were obtained in an effort to measure the strong B --> X emission band of the radical CN in Leonid meteor spectra at 387 nm. CN is an expected product of ablation of nitrogen containing organic carbon in the meteoroids as well as a possible product of the aerothermochemistry induced by the kinetic energy of the meteor. A slit-less spectrograph with objective grating was deployed on FISTA during the 1999 Leonid Multi-Instrument Aircraft Campaign. Fifteen first-order UV spectra were captured near the 02:00 UT meteor storm peak on November 18. It is found that neutral iron lines dominate the spectrum, with no clear sign of the CN band. The meteor plasma contains less than one CN molecule per 3 Fe atoms at the observed altitude of about 100 km.

  10. Dark skies for the Leonids in November

    NASA Astrophysics Data System (ADS)

    Bone, N.

    2007-10-01

    The 2007 return of the Leonids, with peak expected on Saturday night to Sunday morning of November 17-18, is well-placed with respect to moonlight. The Moon, a day past first quarter, will set around midnight UT, just as the shower radiant - in Leo's 'Sickle' asterism - is rising. By necessity, the Leonids are best observed in the early hours when the radiant is climbing higher into the eastern sky. Peak should occur around Nov 18d 05h UT. Observers are encouraged to make the most of this opportunity to obtain coverage of the Leonids as they return to the more 'normal' activity that prevails for two-thirds of their cycle.

  11. Search for Organic Matter in Leonid Meteoroids

    NASA Technical Reports Server (NTRS)

    Rairden, Richard L.; Jenniskens, Peter; Laux, Christophe O.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Near-ultraviolet 300-410 nm spectra of Leonid meteors were obtained in an effort to measure the strong B to X emission band of the radical CN in Leonid meteor spectra at 387 nm. CN is an expected product of ablation of nitrogen containing organic carbon in the meteoroids as well as a possible product of the aerothermochemistry induced by the kinetic energy of the meteor. A slitless spectrograph with objective grating was deployed on FISTA during the 1999 Leonid Multi-Instrument Aircraft Campaign. Fifteen first-order UV spectra were captured near the 02:00 UT meteor storm peak on November 18. It is found that neutral iron lines dominate the spectrum, with no clear sign of the CN band. The meteor plasma contains less than one CN molecule per three Fe atoms at the observed altitude of about 100 km.

  12. Good prospects for the Leonids this November

    NASA Astrophysics Data System (ADS)

    Bone, N.

    2001-10-01

    Although the parent comet 55P/Tempel(Tuttle is now almost four years past perihelion, the Leonids continue to excite considerable interest, with major activity still possible this year. The model of the Leonid meteoroid stream as a collection of interwoven filaments or arcs of material released at separate perihelion passages of the comet, developed by Robert McNaught and David Asher, has been successful both in predicting intervals of high activity, and explaining past outbursts including that of 1998. In 1999, a Leonid storm with corrected Equivalent Zenithal Hourly Rate (EZHR) around 2500(2700 was seen close to the expected time of November 18d 02h UT by observers under clear skies in Sinai and the Mediterranean region.1

  13. The Leonid Fireball Night from Romania

    NASA Astrophysics Data System (ADS)

    Grigore, V.; Berinde, S.

    1999-02-01

    An overview of the 1998 Leonid activity as seen from Romania by SARM members, with a description of the event on November 16-17 as seen by Valentin Grigore (GRIVA) at Targoviste, lambda=25deg 29' 00'' E, phi=44deg 57' 18'' N, h=350m.

  14. Leonid Pavlovich Shil'nikov (obituary)

    NASA Astrophysics Data System (ADS)

    Anosov, Dmitry V.; Afraimovich, Valentin S.; Bunimovich, Leonid A.; Gonchenko, Sergei V.; Grines, Vyacheslav Z.; Ilyashenko, Yulij S.; Katok, Anatolii B.; Kashchenko, Sergey A.; Kozlov, Valerii V.; Lerman, Lev M.; Morozov, Albert D.; Neishtadt, Anatolii I.; Pesin, Yakov B.; Samoilenko, Anatoly M.; Sinai, Yakov G.; Treschev, Dmitrii V.; Turaev, Dmitry V.; Sharkovskii, Aleksandr N.; Shil'nikov, Andrei L.

    2012-06-01

    A remarkable mathematician, one of the most prominent specialists in the theory of dynamical systems and bifurcation theory, a laureate of the Lyapunov Prize of the Russian Academy of Sciences and of the Lavren'ev Prize of the National Academy of Sciences of Ukraine, a Humboldt Professor, Head of the Department of Differential Equations of the Research Institute of Applied Mathematics and Cybernetics of Nizhnii Novgorod University, Professor Leonid Pavlovich Shil'nikov passed away on 26 December 2011.

  15. Meteor storm forecasting: Leonids 1999-2001

    NASA Astrophysics Data System (ADS)

    Ferrin, I.

    1999-08-01

    We present a method for meteor storm forecasting, that we apply to the Leonids in 1999-2001. The method makes use of a plot where the particle density distribution around the comet is mapped (Fig. 1) and isolines of equal meteor intensity are drawn. The most significant result found is the existence of a ``ridge" or region of high particle density, that corresponds to the great Leonid storms and that we identify with the ``dust trails" that Sykes et al. (1990) and Sykes & Walker (1992) found behind all periodic comets. We present detailed calculations of the trajectories of meteoroids that will reproduce this ridge. We predict the intensity of upcoming Leonid showers by the position of the Earth in relation to the isolines. For 1999 we predict a zenith hourly rate (ZHR) of 3.5 K+/-1 K. For the year 2000 we can only limit the intensity to 5 K

  16. Review on international observations and researches of 1998 - 1999 Leonids

    NASA Astrophysics Data System (ADS)

    Liu, Zhongyuan

    2001-06-01

    Great achievements have been gained from Leonid Meteor Shower observations and researches during the period of 1998 - 1999. In this paper, some results and progresses, including visual, radar, airborne, balloon observations, satellite safe monitoring and observations of Leonid impact on the moon and the lunar sodium tail, are presented briefly.

  17. Leonid Storm Flux Analysis From One Leonid MAC Video AL50R

    NASA Technical Reports Server (NTRS)

    Gural, Peter S.; Jenniskens, Peter; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    A detailed meteor flux analysis is presented of a seventeen-minute portion of one videotape, collected on November 18, 1999, during the Leonid Multi-instrument Aircraft Campaign. The data was recorded around the peak of the Leonid meteor storm using an intensified CCD camera pointed towards the low southern horizon. Positions of meteors on the sky were measured. These measured meteor distributions were compared to a Monte Carlo simulation, which is a new approach to parameter estimation for mass ratio and flux. Comparison of simulated flux versus observed flux levels, seen between 1:50:00 and 2:06:41 UT, indicate a magnitude population index of r = 1.8 +/- 0.1 and mass ratio of s = 1.64 +/- 0.06. The average spatial density of the material contributing to the Leonid storm peak is measured at 0.82 +/- 0.19 particles per square kilometer per hour for particles of at least absolute visual magnitude +6.5. Clustering analysis of the arrival times of Leonids impacting the earth's atmosphere over the total observing interval shows no enhancement or clumping down to time scales of the video frame rate. This indicates a uniformly random temporal distribution of particles in the stream encountered during the 1999 epoch. Based on the observed distribution of meteors on the sky and the model distribution, recommendations am made for the optimal pointing directions for video camera meteor counts during future ground and airborne missions.

  18. Leonid Storm Flux Analysis from One Leonid Mac Video AL50R

    NASA Astrophysics Data System (ADS)

    Gural, Peter S.; Jenniskens, Peter

    A detailed meteor flux analysis is presented of a seventeen-minute portion of one videotape, collected on November 18, 1999, during the Leonid Multi-instrument Aircraft Campaign. The data was recorded around the peak of the Leonid meteor storm using an intensified CCD camera pointed towards the low southern horizon. Positions of meteors on the sky were measured. These measured meteor distributions were compared to a Monte Carlo simulation, which is a new approach to parameter estimation for mass ratio and flux. Comparison of simulated flux versus observed flux levels, seen between 1:50:00 and 2:06:41 UT, indicate a magnitude population index of r = 1.8 +/- 0.1 and mass ratio of s = 1.64 +/- 0.06. The average spatial density of the material contributing to the Leonid storm peak is measured at 0.82 +/- 0.19 particles per square kilometer per hour for particles of at least absolute visual magnitude +6.5. Clustering analysis of the arrival times of Leonids impacting the earth's atmosphere over the total observing interval shows no enhancement or clumping down to time scales of the video frame rate. This indicates a uniformly random temporal distribution of particles in the stream encountered during the 1999 epoch. Based on the observed distribution of meteors on the sky and the model distribution, recommendations are made for the optimal pointing directions for video camera meteor counts during future ground and airborne missions.

  19. The heavens on fire : the great Leonid meteor storms

    NASA Astrophysics Data System (ADS)

    Littmann, Mark

    Imagine the night sky so full of shooting stars that the firmament itself seems to be crashing to Earth. When the most spectacular of all meteor showers - the Leonids - passed in 1966, observers saw 40 every second. In 1833, three widely-separated observers described the Leonid storm as `the heavens on fire'. The returning Leonids are now reaching their peak with great activity expected in 1999 and 2000. The Heavens on Fire vividly tells the history of meteors, and especially the Leonids, whose terrifying beauty established meteor science. Mark Littmann traces the history and mythology of meteors, profiles the fascinating figures whose discoveries advanced the field, and explores how meteors have changed the course of life on Earth. He offers advice on how and where to make the best of the 1999 and 2000 Leonid storms. `a must-have for meteor enthusiasts.' Sky and Telescope

  20. Observations of the Leonids in 2006 from Bulgaria

    NASA Astrophysics Data System (ADS)

    Bozhurova, Eva; Koleva, Katya

    2010-12-01

    We report on results from an expediton to Bolyarci 2006 November 17/18 and 18/19. Boris Stoilov (STOBO), Ivaylo Ivanov (IVAIV) and Valentin Velkov (VELVA) recorded 51 Leonids out of 107 meteors in 7.83 hours of total effective observing time. High activity of the Leonids on 2006 November 18/19 around 4:45-4:48 UT as recorded by other contributors to the IMO data base, was confirmed. Processing the plotted meters using the RADIANT software provided radiant positions of the Leonids, alpha-Monocerotids, Taurids, and new iota-Aurigid meteor shower.

  1. Very Precise Orbits of 1998 Leonid Meteors

    NASA Technical Reports Server (NTRS)

    Betlem, Hans; Jenniskens, Peter; vantLeven, Jaap; terKuile, Casper; Johannink, Carl; Zhao, Hai-Bin; Lei, Chen-Ming; Li, Guan-You; Zhu, Jin; Evans, Steve; hide

    1999-01-01

    Seventy-five orbits of Leonid meteors obtained during the 1998 outburst are presented. Thirty-eight are precise enough to recognize significant dispersion in orbital elements. Results from the nights of 1998 November 16/17 and 17/18 differ, in agreement with the dominant presence of different dust components. The shower rate profile of 1998 November 16/17 was dominated by a broad component, rich in bright meteors. The radiant distribution is compact. The semimajor axis is confined to values close to that of the parent comet, whereas the distribution of inclination has a central condensation in a narrow range. On the other hand, 1998 November 17/18 was dominated by dust responsible for a more narrow secondary peak in the flux curve. The declination of the radiant and the inclination of the orbit are more widely dispersed. The argument of perihelion, inclination, and the perihelion distance are displaced. These data substantiate the hypothesis that trapping in orbital resonances is important for the dynamical evolution of the broad component.

  2. Observations of Leonids 2009 by the Tajikistan Fireball Network

    NASA Technical Reports Server (NTRS)

    Borovicka, J.; Borovicka, J.

    2011-01-01

    The fireball network in Tajikistan has operated since 2009. Five stations of the network covering the territory of near eleven thousands square kilometers are equipped with all-sky cameras with the Zeiss Distagon "fish-eye" objectives and by digital SLR cameras Nikon with the Nikkor "fish-eye" objectives. Observations of the Leonid activity in 2009 were carried out during November 13-21. In this period, 16 Leonid fireballs have been photographed. As a result of astrometric and photometric reductions, the precise data including atmospheric trajectories, velocities, orbits, light curves, photometric masses and densities were determined for 10 fireballs. The radiant positions during the maximum night suggest that the majority of the fireball activity was caused by the annual stream component with only minor contribution from the 1466 trail. According to the PE criterion, the majority of Leonid fireballs belonged to the most fragile and weak fireball group IIIB. However, one detected Leonid belonged to the fireball group I. This is the first detection of an anomalously strong Leonid individual.

  3. The Leonid Meteors and Space Shuttle Risk Assessment

    NASA Technical Reports Server (NTRS)

    Pawlowski, James F.; Hebert, Thomas

    2000-01-01

    The November 1999 Leonid meteor shower was videotaped on the grounds of the NASA Johnson Space Center (JSC) and at the JSC Observatory in Cloudcroft, New Mexico. The videotapes were analyzed using a meteor analysis system developed at JSC. The results of the analysis were compared to the Leonid Meteors Mass Distribution Model derived at JSC and used for micrometeoroid and orbital debris risk assessment performed before each Space Shuttle mission. The observed data compared favorably to the model in the .001 to 0.2 gram range but diverged from the model for the smaller masses. We attribute the divergence to optical equipment limitations. These 1999 results will be compared with the 1998 results which were presented at the April 1999 Leonid Multi-Instrument Aircraft Campaign (MAC) Workshop.

  4. The Leonids: The Lion King of Meteor Showers

    NASA Astrophysics Data System (ADS)

    Rao, J.

    1995-08-01

    The night of November 12-13, 1833, sparked awareness of the Leonids meteor shower as well as the birth of meteor astronomy: from much of North America that night, a rain of shooting stars, a shower of flashing light, spread over the entire sky. More than one superstitious person on that spectacular night was certain that the end of the world had come. People kept repeating that the meteors were falling "like snowflakes". In the aftermath of the display, it was realized that meteors could be produced by an extraterrestrial source: streams or swarms of particle that travel around the Sun in more or less well-defined orbits, grazing, at least at one point, the orbit of our Earth. In 1866, G. Schiaparelli established the orbit of the stream of particles that produce the Leonids, and soon others independently noted a striking resemblance of the Leonids with the orbit of periodic comet Tempel-Tuttle. The comet and meteor stream were subsequently found to be following nearly identical orbits with periods of roughly 33 years. A few years earlier (in 1863) it was discovered similarly spectacular Leonid meteor displays had occured prior to 1833, with accounts of the Leonids traceable as far back as A.D. 902. Based solely on the 33-year cycle, a prediction for a meteor storm in the year 1866 verified. In 1899 a re-enactment of the 1833 storm was confidently expected, despite calculations that demonstrated that the orbit of P/Tempel-Tuttle (and probably the associated Leonid particles) were likely perturbed by the planets Jupiter and Saturn. The failure of a storm to materialize seriously damaged the credibility of astronomers in the eyes of the general public. Since 1899, the Leonids have been following a rather erratic and unpredictable schedule: meteor storms unexpectedly occurred in 1900 and 1901; no storm was noted in 1931 and 1932, leading many to believe that Leonid activity had significantly declined. But during the 1960s, they again revived, capped by a short

  5. The Leonid Meteors and Space Shuttle Risk Assessment

    NASA Astrophysics Data System (ADS)

    Pawlowski, James F.; Hebert, Thomas T.

    The November 1999 Leonid meteor shower was videotaped with a low light level camera from the grounds of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) in Houston, Texas. Additionally, observations of the Leonids were recorded both digitally with the Liquid Mirror Telescope (LMT) and with a low light level camera at the JSC Observatory near Cloudcroft, New Mexico. The tapes were analyzed using a computer-automated meteor analysis system developed at JSC. These results were used to form estimates of the Leonid mass-distribution. These estimates were compared to a Leonid mass distribution model used by NASA in risk assessment calculations associated with Space Shuttle missions. The observed data agrees favorably with the NASA model in the 0.002 to 0.02 milligram range (based upon the LMT observations) and in the 0.02 to 0.2 gram range (based upon the low light level camera observations). This comparison supports the continued use of this model.

  6. Possible satellite-based observations of the 1997 Leonid meteoroids

    SciTech Connect

    Pongratz, M.B.; Carlos, R.C.; Cayton, T.

    1998-12-01

    The Block IIA GPS satellites are equipped with a sensor designed to detect electromagnetic transients. Several phenomena will produce triggers in this sensor. They include earth-based electromagnetic transients such as lightning and two space-based phenomena--deep dielectric discharge and meteoroid or hyper-velocity micro-gram particle impact (HMPI). Energetic electrons in the GPS environment cause the deep dielectric charging. HMPIs cause triggers through the transient electric fields generated by the ejecta plasma. During the 1997 Leonid passage the energetic particle fluxes were very low. In the presence of such low fluxes the typical median trigger rate is 20 per minute with a standard deviation of about 20 per minute. Between 0800 UT and 1200 UT on November 17, 1997, the sensor on a specially configured satellite observed trigger rates more than 10 sigma above the nominal median rate. Sensors on other Block IIA GPS satellites also observed excess triggers during November. Detection is enhanced when the sensor antenna is oriented into the Leonid radiant. While many questions persist the authors feel that it is likely that the excess events during the November interval were caused by the close approach of the satellites to the Leonid meteoroid path.

  7. Comparison of 1998 and 1999 Leonid Light Curve Morphology and Meteoroid Structure

    NASA Technical Reports Server (NTRS)

    Murray, Ian S.; Beech, Martin; Taylor, Michael J.; Jenniskens, Peter; Hawkes, Robert L.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Photometric low-light level video observations of 1999 Leonid storm meteors have been obtained from airborne platforms during the Leonid multi-instrument aircraft campaign (Leonid MAC). The 1999 Leonid light curves tend to be skewed towards the end point of the trajectory, while the 1998 Leonid light curves were not. The variation in the light curves from 1998 and 1999 can be explained as an overall reduction in the mass distribution index, alpha from approximately 1.95 in 1998 to approximately 1.75 in 1999. We have interpreted this behavior as being either indicative of a gradual loss of the "glue" that keeps the grains together, or the fact that the meteoroids sampled in 1998 had a different morphological structure to those sampled in 1999. The early fragmentation of a dustball meteoroid results in a light curve that peaks sooner than that predicted by classical single body ablation theory.

  8. Comet dust trails in the post Leonid storm season

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.

    2003-04-01

    An airborne and ground-based observing campaign was organized to cover the 2002 Leonid meteor storms. Two dust trails of comet 55P/Tempel-Tuttle were directed in Earth's path by planetary perturbations, dating from ejection in 1766 (~ 04:00 UT, Nov. 19) and 1866 (~ 10:30 UT, Nov. 19). Models of comet dust formation and evolution predicted a range of relative peak strength and stream cross section. The airborne effort was deployed from Spain. Enroute to Nebraska, both storm peaks were observed under excellent observing conditions. European observers saw the first storm peak at 04:06 UT (ZHR ~ 2,300/hr), while observers in the America's witnessed a storm peaking at 10:47 UT (ZHR ~ 2,600/hr). Both peaks were narrow, with a full-width-at-half-maximum of only 0.52 and 0.50 hours, respectively, in good agreement with only one of the models, which does not include broadening over time by radiation pressure or perturbations on dynamically different orbits. The strong showing of the 1767-dust trail relative to that of 1866 illustrates again that the trail positions are slightly further inward to the sun than calculated in earlier models. High rates persisted between the two storm peaks, which is probably a manifestation of the Leonid Filament, peaking before 03 UT. The Fillament is thought to be due to perturbations of orbital period over more revolutions. The high abundance of faint meteors in both peaks is a puzzle. Although the smaller grains are supposed to have the higher surface-to-mass ratio and therefore the stronger push from water drag during ejection and solar radiation pressure while in orbit, last year's Leonid storms did not show that effect. Predictions for future meteor outbursts of other streams in the next fifty years will be discussed, which can help increase our understanding of the dynamical evolution of comet dust in the solar system.

  9. Forecast for the Remainder of the Leonid Storm Season

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The dust trails of comet 55P/Tempel-Tuttle lead to Leonid storms on Earth, threatening satellites in orbit. We present a new model that accounts in detail for the observed properties of dust tails evolved by the comet at previous oppositions. The prediction model shows the 1767-dust trail closer to Earth's orbit in 2001 than originally thought; increasing expected peak rates for North America observers. Predictions for the 2002 storms are less affected. We demonstrate that the observed shower profiles can be understood as a projection of the comet lightcurve.

  10. 2002 Leonid storm fluxes and related orbital elements

    NASA Astrophysics Data System (ADS)

    Trigo-Rodríguez, Josep M.; Llorca, Jordi; Lyytinen, Esko; Ortiz, Jose Luis; Caso, Albert Sánchez; Pineda, Carles; Torrell, Sebastià

    2004-09-01

    We report here the observation of the first peak belonging to the 2002 Leonid meteor storm made during the night of November 18-19, 2002. This feature, produced by a 7-revolution dust trail, was observed from several photographic stations of the Spanish Photographic Meteor Network (SPMN) and one video station operated from the Instituto de Astrofı´sica de Andalucı´a (IAA) in an intensive campaign from the ground working in collaboration with the 2002 Leonid MAC mission. We used photography, slow-scan Charge Coupled Devices (CCD) and video CCD-imaging techniques to deduce the meteoroid flux density profiles in different ranges of masses. Additionally, we present multi-station work, developed during the storm, that allows us to deduce the orbital elements of ten meteoroids associated with this dust trail. We have found a clear similarity between their orbits and the one belonging to a theoretical orbit for particles ejected from 55P/Tempel-Tuttle in 1767.

  11. Time Resolved Spectroscopy of a Leonid Fireball Afterglow

    NASA Astrophysics Data System (ADS)

    Borovička, Jiří.; Jenniskens, Peter

    Two video spectra of a meteoric afterglow were obtained for the first time during the 1999 Leonid aircraft campaign. The train was produced by a -13 magnitude Leonid fireball at a relatively low height between 91-75 km. The meteor spectrum has a strong hydrogen emission, proportional to 10-20 II atoms per one Fe atom The train spectrum consisted of a red continuum, yellow continuum, and about 50 atomic lines between 3700-9000 Å. The yellow continuum, possibly due to NO_2, was also detected in the persistent train. The red continuum is interpreted as a thermal radiation of dust from meteoric debris at about 1400 K. Evidence for secondary ablation is found in the afterglow. The atomic lines decayed within seconds of the meteor. The lines of Fe I, Mg I, Na I, Ca I, Ca II, Cr I, Mn I, K I, and possibly Al I were present in the glow together with the 5577 Å forbidden O I line. The gas temperature in the train was close to 5000 K at the beginning and decayed to 1200 K within two seconds. However, thermal equilibrium was not satisfied for all populated levels.

  12. The 2002 Leonid Multi-Instrument Aircraft Campaign

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.

    2003-04-01

    The final mission in the NASA and USAF sponsored Leonid Multi-Instrument Campaign consisted of two instrumented aircraft that flew from Madrid, Spain, to Omaha, Nebraska, putting 38 participating researchers from seven nationalities in a position to study both November 19, 2002, Leonid meteor storms under excellent observing conditions. Two storms were anticipated to result from Earth's encounter with dust ejected by comet 55P/Tempel-Tuttle in 1767 and 1866 (peak at 04:00 and 10:40 UT). Planetary perturbations directed these dust trails in Earth's path. The mission was deployed out of Torrejon de Ardoz, near Madrid, where we were hosted by the Centro de Astrobiologia. In the night of November 19, both aircraft were above clouds en route to Omaha, with a radiant climbing from 35 to 67 degrees and the full Moon relatively low in the sky. All instruments worked as expected. Meteor storms were observed peaking at 04:06 and 10:47 UT, much as predicted. The presentations is a brief overview of experiments and first results, which include new insight into comet dust trail formation and dynamics, comet mass loss, and measurements of elemental abundances of cometary dust and of grain morphology.

  13. Russian Revolutions, Lenin and Trotzky in a Book by Leonid Dobronravov (Donitch)

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    Some reflections concerning the role of Communist Party in the development of sciences and arts in the Soviet Union, following from the book by Leonid Dobronravov (Donitch)(Russian Revolution) and writings by Gennady Gorelik are given.

  14. Mid-Infrared Spectroscopy of Persistent Leonid Trains

    NASA Technical Reports Server (NTRS)

    Russell, Ray W.; Rossano, George S.; Chatelain, Mark A.; Lynch, David K.; Tessensohn, Ted K.; Abendroth, Eric; Kim, Daryl; Jenniskens, Peter; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The first infrared spectroscopy in the 3-13 micron region has been obtained of several persistent Leonid meteor trains with two different instrument types, one at a desert ground-based site and the other on-board a high-flying aircraft. The spectra exhibit common structures assigned to enhanced emissions of warm CH4, CO2, CO and H2O which may originate from heated trace air compounds or materials created in the wake of the meteor. This is the first time that any of these molecules has been observed in the spectra of persistent trains. Hence, the mid-IR observations offer a new perspective on the physical processes that occur in the path of the meteor at some time after the meteor itself has passed by. Continuum emission is observed also, but its origin has not yet been established. No 10 micron dust emission feature has been observed.

  15. Complex Traits and Simple Systems: An Interview with Leonid Kruglyak

    PubMed Central

    Kruglyak, Leonid

    2016-01-01

    The Genetics Society of America’s Edward Novitski Prize recognizes an extraordinary level of creativity and intellectual ingenuity in the solution of significant problems in genetics research. The 2016 winner, Leonid Kruglyak, has made innovative contributions to the fields of linkage analysis, population genetics, and genomics, while drawing on a combination of mathematical, computational, and experimental approaches. Among other achievements, his work on statistical standards for genome-wide linkage studies has transformed their experimental design, and the linkage analysis program GENEHUNTER has been used to identify hundreds of human disease loci. Kruglyak’s group also pioneered expression quantitative trait locus studies, which enabled variation in global gene expression to shed light on the genetics of complex human diseases. In recent years, his laboratory has focused on using genomic technology to establish Saccharomyces cerevisiae and Caenorhabditis elegans as model organisms for studies of complex genetic variation. PMID:27384025

  16. STS-87 Payload Specialist Leonid K. Kadenyuk suits up

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine gives a thumbs up in his launch and entry suit in the Operations and Checkout Building. He and the five other crew members of STS-87will depart shortly for Launch Pad 39B, where the Space Shuttle Columbia awaits liftoff on a 16-day mission to perform microgravity and solar research. Kadenyuk will be flying his first mission on STS-87. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbias middeck and features an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings.

  17. Formation of the Leonid meteor stream and storm

    NASA Technical Reports Server (NTRS)

    Wu, Zidian; Williams, I. P.

    1992-01-01

    It is well known that some meteor showers display a very high level of activity at certain times, the most famous being the Leonid shower with very spectacular displays at roughly 33 year intervals. This period being also the period of the parent comet of the stream, Comet Tempel-Tuttle. An investigation of the geometry of the comet and the Earth at the time of each high activity occurrence by Yeomans suggests that most of the meteoroids are found outside the cometary orbit and lagging the comet. The formation process of such a stream by numerically integrating the orbits of dust particles ejected from the comet and moving under the influence of gravity and radiation pressure are simulated. The intersection of these dust particles with the Earth is also considered and it is concluded that about 12 percent of the ejected particles may be observed and that of those observable, 63 percent will be outside the cometary orbit and behind the comet.

  18. Matters arising from ``The Leonid meteor shower and the history of the Semites''Letter - Matters arising from ``The Leonid meteor shower and the history of the Semites''

    NASA Astrophysics Data System (ADS)

    McBeath, A.

    2009-10-01

    Aspects of a paper by Suleyman (2009) in this journal, relating to theoretically-strong Leonid activity in 569 AD and 1226 BC possibly having been recorded in the Quran and Bible respectively, are discussed. Little reason is found to suppose either textual source referred to such astronomical events.

  19. Leonid's Particle Analyses from Stratospheric Balloon Collection on Xerogel Surfaces

    NASA Technical Reports Server (NTRS)

    Noever, David; Phillips, Tony; Horack, John; Porter, Linda; Myszka, Ed

    1999-01-01

    Recovered from a stratospheric balloon above 20 km on 17-18 November 1998, at least eight candidate microparticles were collected and analyzed from low-density silica xerogel collection plates. Capture time at Leonids' storm peak was validated locally along the balloon trajectory by direct video imaging of meteor fluence up to 24/hr above 98% of the Earth's atmosphere. At least one 30 micron particle agrees morphologically to a smooth, unmelted spherule and compares most closely in non-volatile elemental ratios (Mg/Si, Al/Si, and Fe/Si) to compositional data in surface/ocean meteorite collections. A Euclidean tree diagram based on composition makes a most probable identification as a non-porous stratospherically collected particle and a least probable identification as terrestrial matter or an ordinary chondrite. If of extraterrestrial origin, the mineralogical class would be consistent with a stony (S) type of silicate, olivine [(Mg,Fe)2SiO4] and pyroxene [(Mg, Fe)Si!O3)--or oxides, herecynite [(Fe,Mg) Al2O4].

  20. Leonid meteor ablation, energy exchange and trail morphology

    SciTech Connect

    Zinn, John; Judd, O'Dean P.; ReVelle, D. O.

    2002-01-01

    This paper describes theoretical model studies of the interaction of Leonid meteoroids with the earth's atmosphere. Subject to some modest-to-strenuous approximations we compute the rates of ablation and deceleration, energy deposition, and terminal altitudes of the meteors as functions of their initial mass and bulk density, velocity, trajectory entry angle, drag coefficient, heat of ablation, and an ablation energy transfer fraction. We find that the dominant energy deposition in the atmosphere is associated with the stopping of the ablated meteor particles and vapor by the surrounding air. Then having computed the energy deposition rates versus altitude we compute the hydrodynamic and radiative expansion of the hot wake material in the radial direction, along with the associated air chemistry. From the computed results we can then plot two-dimensional temperature contours -- as functions of the instantaneous distance behind the meteor and radial distance from the center of the wake, at various altitudes along the meteor's path. We also compute the rates of emission of radiation and the radiative efficiency, and discuss comparisons with observations.

  1. Observations of Leonid Meteors Using a Mid-Wave Infrared Imaging Spectrograph

    NASA Technical Reports Server (NTRS)

    Rossano, G. S.; Russell, R. W.; Lynch, D. K.; Tessensohn, T. K.; Warren, D.; Jenniskens, P.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    We report broadband 3-5.5 micrometer detections of two Leonid meteors observed during the 1998 Leonid Multi-Instrument Aircraft Campaign. Each meteor was detected at only one position along their trajectory just prior to the point of maximum light emission. We describe the particular aspects of the Aerospace Corp. Mid-wave Infra-Red Imaging Spectrograph (MIRIS) developed for the observation of short duration transient events that impact its ability to detect Leonid meteors. This instrument had its first deployment during the 1998 Leonid MAC. We infer from our observations that the mid-infrared light curves of two Leonid meteors differed from the visible light curve. At the points of detection, the infrared emission in the MIRIS passband was 25 +/- 4 times that at optical wavelengths for both meteors. In addition, we find an upper limit of 800 K for the solid body temperature of the brighter meteor we observed, at the point in the trajectory where we made our mid-wave infrared detection.

  2. C-H Hot Bands in the Near-IR Emission Spectra of Leonids

    NASA Technical Reports Server (NTRS)

    Freund, F. T.; Scoville, J.; Holm, R.; Seelemann, R.; Freund, M. M.

    2002-01-01

    The reported infrared (IR) emission spectra from 1999 Leonid fireballs show a 3.4 micron C-H emission band and unidentified bands at longer wavelengths. Upon atmospheric entry, the Leonid meteorites were flash-heated to temperatures around 2400K, which would destroy any organics on the surface of the meteorite grains. We propose that the nu(sub )CH emission band in the Leonid emission spectra arises from matrix-embedded C(sub n)-H-O entities that are protected from instant pyrolysis. Our model is based on IR absorption nu(sub )CH bands, which we observed in laboratory-grown MgO and natural olivine single crystals, where they arise from C(sub n)-H-O units imbedded in the mineral matrix, indicative of aliphatic -CH2- and -CH3 organics. Instead of being pyrolyzed, the C(sub n)-H-O entities in the Leonid trails become vibrationally excited to higher levels n = 1, 2, 3 etc. During de-excitation they emit at 3.4 microns, due to the (0 => 1) transition, and at longer wavelengths, due to hot bands. As a first step toward verifying this hypothesis we measured the C-H vibrational manifold of hexane (C6H14). The calculated positions of the (2 => l ) , (3 => 2), and possibly (4 => 3) hot bands agree with the Leonid emission bands at 3.5, 3.8 and 4.l microns.

  3. The 1998 Leonid Multi-Instrument Aircraft Campaign-An Early Review

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Butow, Steven J.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    The 1998 return of the Leonid shower was the target of the Leonid multi-instrument aircraft campaign (Leonid MAC), an unusual two-aircraft astronomical research mission executed near Okinawa, Japan. The prospect of a meteor storm brought 28 researchers of 7 nationalities together in a concerted effort to observe the shower by imaging, spectroscopic, and ranging techniques. This paper is a review of the major science issues that are behind the deployment of each of the present array of instruments and describes the interconnection of the various experiments. This was NASA's first astrobiology mission. The mission also aimed to study contemporary issues in planetary astronomy, in atmospheric sciences, and concerning the satellite impact hazard. First results of the participating observers are discussed and put in context, in preparation for the deployment of a planned second mission in November of 1999.

  4. LEONID METEOROIDS: RECONCILIATION OF COMETARY OUTGASSING THEORY AND ELECTROPHONIC SOUND DATA

    SciTech Connect

    Molina, A.

    2011-05-15

    We determine the size of the largest particles that can be lifted from the nuclear surface of the comet 55P/Tempel-Tuttle using a classical outgassing model. The values obtained are in agreement with the estimated lower bound to the diameter of a Leonid meteoroid just capable of producing electrophonic sounds. Thus, we reconcile the discrepancy found by Beech between the estimated value for the maximum diameter of the particle ejected from the parent comet and the size of the 1833 Leonid meteoroid calculated as necessary to produce electrophonic sound.

  5. The Dynamical Evolution of A Tubular Leonid Persistent Train

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Nugent, David; Plane, John M. C.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The dynamical evolution of the persistent train of a bright Leonid meteor was examined for evidence of the source of the luminosity and the physical conditions in the meteor path. The train consisted of two parallel somewhat diffuse luminous tracks, interpreted as the walls of a tube. A general lack of wind shear along the trail allowed these structures to remain intact for nearly 200 s, from which it was possible to determine that the tubular structure expanded at a near constant 10.5 m/s, independent of altitude between 86 and 97 km. An initial fast decrease of train intensity below 90 km was followed by an increase in intensity and then a gradual decrease at longer times, whereas at high attitudes the integrated intensity was nearly constant with time. These results are compared to a model that describes the dynamical evolution of the train by diffusion, following an initial rapid expansion of the hot gaseous trail behind the meteoroid. The train luminosity is produced by O ((sup 1)S) emission at 557 nm, driven by elevated atomic O levels produced by the meteor impact, as well as chemiluminescent reactions of the ablated metals Na and Fe with O3. Ozone is rapidly removed within the train, both by thermal decomposition and catalytic destruction by the metallic species. Hence, the brightest emission occurs at the edge of the train between outwardly diffusing metallic species and inwardly diffusing O3. Although the model is able to account plausibly for a number of characteristic features of the train evolution, significant discrepancies remain that cannot easily be resolved.

  6. The Dynamical Evolution of a Tubular Leonid Persistent Train

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter; Nugent, David; Plane, John M. C.

    The dynamical evolution of the persistent train of a bright Leonid meteor was examined for evidence of the source of the luminosity and the physical conditions in the meteor path. The train consisted of two parallel somewhat diffuse luminous tracks, interpreted as the walls of a tube. A general lack of wind shear along the trail allowed these structures to remain intact for nearly 200 s, from which it was possible to determine that the tubular structure expanded at a near constant 10.5 ms^-1, independent of altitude between 86 and 97 km. An initial fast decrease of train intensity below 90 km was followed by an increase in intensity and then a gradual decrease at longer times, whereas at high altitudes the integrated intensity was nearly constant with time. These results are compared to a model that describes the dynamical evolution of the train by diffusion, following an initial rapid expansion of the hot gaseous trail behind the meteoroid. The train luminosity is produced by O (^1S) emission at 557 nm, driven by elevated atomic O levels produced by the meteor impact, as well as chemiluminescent reactions of the ablated metals Na and Fe with O_3. Ozone is rapidly removed within the train, both by thermal decomposition and catalytic destruction by the metallic species. Hence, the brightest emission occurs at the edge of the train between outwardly diffusing metallic species and inwardly diffusing O_3. Although the model is able to account plausibly for a number of characteristic features of the train evolution, significant discrepancies remain that cannot casily be resolved.

  7. Leonid Breznev and Richard Nixon examine plaques presented by Skylab crew

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Leonid I. Breznev, General Secretary of the Communist Party, Union of Soviet Socialist Republics, and President Richard M. Nixon, during ceremonies at the Western White House in San Clemente, California, examine plaques presented by Skylab astronauts Charles Conrad Jr., center; Joseph P. Kerwin, second from right; and Paul J. Weitz, left.

  8. An ET Origin for Stratospheric Particles Collected during the 1998 Leonids Meteor Shower

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Phillips, James A.; Horack, John M.; Jerman, Gregory; Myszka, Ed

    1999-01-01

    On 17 November 1998, a helium-filled weather balloon was launched into tfle strato- sphere, equipped with a xerogel microparticle collector. The three-hour flight was designed to sample the dust environment in the stratosphere during the Leonid meteor shower, and possibly to capture Leonid meteoroids. Environmental Scanning Election Microscope analyses of the returned collectors revealed the capture of a -30-pm particle. with a smooth, multigranular shape, and partially melted, translucent rims; similar to known Antarctic micrometeorites. Energy-dispersive X-ray Mass Spectroscopy shows en- riched concentrations of the non-volatile elements, Mg, Al, and Fe. The particle possesses a high magnesium to iron ratio of 2.96, similar to that observed in 1998 Leonids meteors (Borovicka, et al. 1999) and sharply higher than the ratio expected for typical material from the earth's crust. A statistical nearest-neighbor analysis of the abundance ratios Mg/Si, Al/Si, and Fe/Si demonstrates that the particle is most similar in composition to cosmic spherules captured during airplane flights throucrh the stratosphere. The mineralogical class is consistent with a stony (S) type of silicates. olivine [(Mg, Fe)2SiO4] and pyroxene [(Mg,Fe)SiO3]-or oxides, herecynite [(Fe,Mg) Al2O4]. Attribution to the debris stream of the Leonids' parent body, comet Tempel-Tuttle, would make it the first such material from beyond the orbit of Uranus positively identified on Earth.

  9. Matching cometary ejection processes to the Leonids 1998-2001 using a hybrid numerical model

    NASA Astrophysics Data System (ADS)

    Welch, P. G.

    2003-07-01

    A new scheme for simulating meteor showers is introduced, based on a hybridization of current numerical modelling techniques. It involves an iterative method that generates particles which hit a real-scale Earth, removing the spatial and temporal blurring common to other modelling techniques. The scheme is applied to the activity profile of the Leonids 2001 using three different models of meteoroid ejection velocity and then applied to the Leonids 1998-2000 using the most favourable models. It is shown that to reproduce the observed meteor activity profiles there must be a strong concentration of ejection around perihelion. The modelling also implies that meteoroid density must be towards the higher end of the currently acceptable range, although the derived limits are not independent of the ejection velocity model. We also find that the extreme narrowness of Leonid activity peaks is not easily reproduced with outgassing over the entire day side of the comet but it is fitted well by outgassing in a restricted direction as one would expect from an outgassing jet. In addition, we show that double-peaked features, corresponding to a semihollow meteoroid streamlet, can arise in a meteor shower activity profile from outgassing during a single perihelion passage of the parent comet. It is suggested that this process caused the double-peaked feature in the first maxima of the 2001 Leonids.

  10. Large Leonid entry modeling : application to the bolide of 11/17/1998

    SciTech Connect

    ReVelle, D. O.

    2001-01-01

    In this paper we apply the theoretical entry model of ReVelle (2001c) to the large Leonid bolide of November 17, 1998. We modeled the entry both using hypersonic aerodynamics and compared the results to the infrasonic detection and interpretation of the event by ReVelle and Whitaker (1999).

  11. Observations of the Leonid Meteoroid Stream by a Multistation FS Radio System

    NASA Astrophysics Data System (ADS)

    Cevolani, Giordano; Pupillo, Giuseppe; Hajduk, Anton; Porubčan, Vladimir

    Results of joint campaigns of the Leonid meteoroid stream performed throughout the 1995-1999 years by the BLM (Bologna-Lecce-Modra) forward scatter (FS) radar, are shown and compared with visual observations. In 1998 and 1999 at both the stations of Lecce and Modra, the total reflection time is shown to give a better indication of the Leonid activity. For the two years the trends of the reflection time and of the overdense echoes (T > 8 sec duration) exhibit multiple peaks just at the maximum of the shower activity. In 1999, strong evidence of a short and extremely intense activity at the nodal longitude of the parent comet (November 18, 02h UT), is deduced from the radio data. The Leonid display is shown to follow a Gaussian activity profile and the particle density/stream width relationship is found to match observations of IRAS dust trails of comparable short-period comets. The mass distribution exponent shows a representation of an extended component of larger particles (brighter Leonids) in 1996 and especially in 1998. Average mass and population indices of radio and visual data show a similar trend in the 1995-1999 period.

  12. Infrasonic Detection of a Leonid Bolide: November 17, 1998

    NASA Astrophysics Data System (ADS)

    Revelle, Douglas O.; Whitaker, Rodney W.

    1999-11-01

    During the early morning hours of the night of the peak of the annual Leonid meteor shower on November 17, 1998, a bright fireball (~ -12--14 visual magnitude at 100 km in the zenith) was observed over Northern New Mexico with visual sightings as far away from Los Alamos as Albuquerque (~150 km to the south of Los Alamos), including direct persistent trail observations at the USAF Starfire Optical Range (SOR), which is also near Albuuqerque. This event did not produce any sonic boom reports presumably because of the its high altitude. It was also detected locally by an infrared radiometer at Sandia National Laboratory and by an intensified CCD camera located in Placitas, New Mexico. Subsequent investigations of the data from the six infrasound arrays used by LANL (Los Alamos National Laboratory) and operated for the DOE (Department of Energy) as a part of the CTBT (Comprehensive Test Ban Treaty) Research and Development program for the IMS (International Monitoring System) showed the presence of an infrasonic signal from the proper direction at the correct time for this bolide from two of our six arrays (both located in Los Alamos). The infrasound recordings, i.e., the wave amplitude and period data, indicated that an explosion occurred in the atmosphere at a source height of about ~93.5 km, having its origins slightly to the north and west of Los Alamos. Purely geometric solutions from the ground observers reports combined with direct measurements from the CCD camera at Placitas produced a source height of 91 +/- 7 km. The signal characteristics analyzed from 0.10 to 3.0 Hz, include a total duration of ~ 3 - 4 sec for a source directed from Los Alamos toward 353.6 +/- 0.3 deg measured from true north at a maximum elevation arrival angle of ~ 72.7 degrees. The latter was deduced on the basis of the observed signal trace velocities (for the part of the recording with the highest cross-correlation) and ranged from a constant value of ~920-1150 m/sec (depending on the

  13. A Study Of Leonid Impact Flashes On The Moon In 2004

    NASA Astrophysics Data System (ADS)

    Ortiz, J. L.; Aceituno, F. J.; Santos-Sanz, P.; Quesada, J. A.

    2005-08-01

    In November 2004 the lunar phase was adequate to observe lunar impact flashes at the time of the Leonid meteor shower, as it was the case in 1999 and 2001, because a large number of meteoroidal impacts were expected to hit the night part of the Moon visible from Earth. We again arranged a special multisite observing campaign with telescopes aiming at the night part of the Moon in order to detect and analyze such flashes. In this paper we report our unambiguous detections, our computations of the energy released in each impact, their locations on the Moon and possible inferences on crater sizes. Those fresh craters might perhaps be observable from SMART-1. Some implications on Leonid meteor fluxes on Earth and size distribution of the particles are also discussed. This research was supported by the spanish AYA-2002-0382 project. FEDER funds are also acknowledged.

  14. FeO "Orange Arc" Emission Detected in Optical Spectrum of Leonid Persistent Trains

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Lacey, Matt; Allan, Beverly J.; Self, Daniel E.; Plane, John M. C.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    We report the detection of a broad continuum emission dominating the visual spectrum of a Leonid persistent train. A comparison with laboratory spectra of FeO 1 "orange arc" emission at I mbar shows a general agreement of the band position and shape. The detection of FeO confirms the classical mechanism of metal atom catalyzed recombination of ozone and oxygen atoms as the driving force behind optical emission from persistent trains. Sodium and iron atoms are now confirmed catalysts.

  15. Characteristics of Fe Ablation Trials Observed During the 1998 Leonid Meteor Shower

    NASA Technical Reports Server (NTRS)

    Chu, Xin-Zhao; Pan, Wei-Lin; Papen, George; Swenson, Gary; Gardner, Chester S.; Jenniskens, Peter; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Eighteen Fe ablation trails were observed during the 17/18 Nov 1998 Leonid meteor shower with an airborne Fe lidar aboard the National Simulation Facility/National Center for Atmospheric Research (NSF/NCAR) Electra aircraft over Okinawa. The average altitude of the 18 trails from the high velocity (72 km/s) Leonid meteors, 95.67 +/- 0.93 km, is approximately 6.7 km higher than previously observed for slower (approx. 30 km/s) sporadic meteors. This height difference is consistent with the assumption that meteors ablate when the kinetic energy imparted to the atmosphere reaches a critical threshold. The average age of the Fe trails, determined by a diffusion model, is 10.1 min. The youngest ages were observed below 92 km and above 98 km where chemistry and diffusion dominate, respectively. The average abundance of the trails is ten percent of the abundance of the background Fe layer. Observations suggest that the 1998 Leonid shower did not have a significant impact on the abundance of the background Fe layer.

  16. The 1999 Leonid Multi-Instrument Aircraft Campaign - An Early Review

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter; Butow, Steven J.; Fonda, Mark

    Two B707-type research aircraft of the 452^nd Flight Test Squadron at Edwards Air Force Base were deployed to study the Leonid meteor storm of 1999 over the Mediterranean Sea on Nov. 18. The mission was sponsored by various science programs of NASA, and offered an international team of 35 researchers observing conditions free of clouds and low altitude extinction at a prime location for viewing the storm. This 1999 Leonid Multi-Instrument Aircraft Campaign followed a similar effort in 1998, improving upon mission strategy and scope. As before, spectroscopic and imaging experiments targeted meteors and persistent trains, but also airglow, aurora, elves and sprites. The research aimed to address outstanding questions in astrobiology, planetary science, astronomy, and upper atmospheric research. In addition, USAF co-sponsored the mission to provide near real-time flux measurements for space weather awareness. First results are presented in these issues of Earth, Moon, and Planets in preparation for future missions that will target the exceptional Leonid returns of 2001 and 2002. An early review of the scientific achievements in the context of campaign objectives is given.

  17. High resolution radar observations of the 1999, 2000 and 2001 Leonid meteor storms over middle Europe and Northern Scandinavia

    NASA Astrophysics Data System (ADS)

    Latteck, R.; Singer, W.; Mitchell, N. J.; Weiss, J.; von Zahn, U.

    2004-01-01

    Observations of the Leonid meteor storms have been made with all-sky meteor radars at Juliusruh, Germany (54.6°N), at Kiruna, Sweden (67.9°N) and at Andenes, Norway (69.3°N) in 1999, 2000, and 2001. In the Juliusruh and Andenes experiments acquisition parameters were selected to acquire data at the highest possible rate with an optimum time resolution to locate as many meteors as possible as well as to determine the high entry velocities of the Leonid meteors. Height-dependent meteor rates and distributions of the meteor entry velocities were analyzed in the altitude range 80-115 km with a time-resolution of 10 min (1999 and 2000) and 20 min (2001). During each of the three storm periods, the Leonid storm activity was most prominent at altitudes above 100 km with counts much higher than usual and short-time variations in the Leonid activity were clearly revealed by the radars. Temporary peaks in the Leonid activity during the storms depicted in the radar observations were more pronounced than in the ZHR-curve derived from a multitude of visual observers.

  18. Do comets have chondrules and CAIs? Evidence from the Leonid meteors

    NASA Astrophysics Data System (ADS)

    Swindle, Timothy D.; Campins, Humberto

    2004-10-01

    Chondrules, silicate spheres typically 0.1 to 1 mm in diameter, are the most abundant constituents in the most common meteorites falling on Earth, the ordinary chondrites. In addition, many primitive meteorites have calcium-aluminum-rich inclusions (CAIs). The question of whether comets have chondrules or CAIs is relevant to understanding what the interior of a comet is like and what a cometary meteorite might be like. In addition, one prominent model for forming chondrules and CAIs, the X-wind model, predicts their presence in comets, while most other models do not. At present, the best way to search for chondrules and CAIs in comets is through meteor showers derived from comets, in particular, the Leonid meteor shower. Evidence potentially could be found in the overall mass distribution of the shower, in chemical analyses of meteors, or in light curves. There is no evidence for a chondrule abundance in the Leonid meteors similar to that found in chondritic meteorites. There is intriguing evidence for chondrule- or CAI-sized objects in a small fraction of the light curves, but further work is required to generate a definitive test.

  19. Leonid Shower Probe of Aerothermochemistry in Meteoric Plasmas and Implication for the Origin of Life

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter S. I.; Packan, D.; Laux, C.; Wilson, Mike; Boyd, I. D.; Kruger, C. H.; Popova, O.; Fonda, M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The rarefied and high Mach number (up to 270) of the flow field of a typical meteoroid as it enters the Earth's atmosphere implies conditions of ablation and atmospheric chemistry that have proven to be as difficult to grasp as the proverbial shooting star. An airborne campaign was organized to study these processes during an intense Leonid shower. A probe of molecular band emission now demonstrates that the flash of light from a common meteor originates in the wake of the object rather than in the meteor head. A new theoretical approach using the direct simulation Monte Carlo technique demonstrates that the ablation process is critical in heating the air in that wake. Air molecules impinge on a dense cloud of ablated material in front of the meteoroid head into an extended wake that has the observed excitation temperatures. These processes determine what extraterrestrial materials may have been delivered to Earth at the time of the origin of life.

  20. The ESOC "Meteor Alert Center" (MALC) and Its Application during the 1999 Leonid Shower

    NASA Astrophysics Data System (ADS)

    Zender, Joe; Koschny, Detlef; Neira, Luis

    Spacecraft operators were concerned that the high number density of meteoroid particles during the anticipated 1999 Leonid meteor storm might result in damage to spacecraft. Switching off a spacecraft is expensive and operators try to avoid it, which created a need for real time monitoring systems. At the Space Science Department of ESA, we designed a near-real time meteor monitoring system, displaying observational information at the European Space Operations Center (ESOC) in Darmstadt, Germany. The system consisted of software tools that connect automatic video systems in the field with a central data node. Here, we describe the design, implementation, setup and results of the system. Wireless communication was implemented by means of the Global System for Mobile (GSM) communication. Unfortunately, during the operational phase this communication system failed. Conventional transmission by telephone was used instead. Results of the near real time reporting are presented and discussed.

  1. The 1999 Leonid Multi-Instrument Aircraft Campaign - An Early Review

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Butow, Steven J.; Fonda, Mark; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The Leonid meteor storm of 1999 was observed from two B707-type research aircraft by a team of 35 scientists of seven nationalities over the Mediterranean Sea on Nov. 18, 1999. The mission was sponsored by various science programs of NASA, and offered the best possible observing conditions, free of clouds and at a prime location for viewing the storm. The 1999 mission followed a similar effort in 1998, improving upon mission strategy and scope. As before, spectroscopic and imaging experiments targeted meteors and persistent trains, but also airglow, aurora, elves and sprites. The research aimed to address outstanding questions in Planetary Science, Astronomy, Astrobiology and upper atmospheric research, including Aeronornie. In addition, near real-time flux measurements contributed to a USAF sponsored program for space weather awareness. An overview of the first results is given, which are discussed in preparation for future missions.

  2. Origin and evolution of recent Leonid meteor showers. [perturbed motion of meteor stream

    NASA Technical Reports Server (NTRS)

    Mcintosh, B. A.

    1973-01-01

    The four most prominent returns of the Leonid shower in the past decade fall into two broad classes. The 1966 and 1969 showers were of short duration, had a high proportion of small particles, and occured with the longest apparent delay after the perihelion passage of the parent comet Temple-Tuttle. By contrast, the 1961 and 1965 returns were of long duration, and had more large particles. The 1961 return preceded the comet. There are three major influences on particle orbits: ejection velocity, radiation pressure, and close encounters with planets. The observations are explainable in a qualitative way on the basis of the first two. But some speculation concerning the results of planetary perturbations are invoked.

  3. Precise Trajectories and Orbits of Meteoroids from the 1999 Leonid Meteor Storm

    NASA Technical Reports Server (NTRS)

    Betlem, Hans; Jenniskens, Peter; Spurny, Pavel; VanLeeuwen, Guus Docters; Miskotte, Koen; TerKuile, Casper R.; Zerubin, Peter; Angelos, Chris; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Photographic multi-station observations of 47 Leonid meteors are presented that were obtained from two ground locations in Spain during the 1999 meteor storm. We find an unresolved compact cluster of radiants at alpha = 153.67 +/- 0.05 and delta = 21.70 +/- 0.05 for a mean solar longitude of 235.282 (J2000). The position is identical to that of the November 17/18 outburst of 1998, which implies that both are due to comet 55P/Tempel-Tuttle's ejecta from 1899. We also find a halo which contains about 28% of all meteors. The spatial distribution of radiant positions appears to be Lorentzian, with a similar fraction of meteors in the profile wings as the meteor storm activity curve.

  4. The Leonid meteor shower and the history of the Semites (Arabs and Jews)

    NASA Astrophysics Data System (ADS)

    Suleyman, Mohammed Omar

    2009-06-01

    Every 33 years, when Comet Tempel-Tuttle returns into the inner Solar system, the Earth crosses the most compact part of its dust swarm and this sometimes causes a heavy meteor shower. This paper investigates two legends of the Semites and tries to prove their connection with the `stars shower'. The first legend, connected with the history of the Arabs, tells about the miraculous rescue of Mecca when f/locks of birds dropped small stones on the army of Abraha and masses of his warriors died. The second legend, connected with the history of the Jews, says that the seventh plague which God sent on Egypt at the behest of Moses was a heavy fall of hail. In this paper we argue that the `stars shower' of the Leonid meteor stream was responsible for the two phenomena observed in those two legends, and this happened respectively on 569 AD October 8th and 1226 BC August 15th.

  5. Jet-Like Structures and Wake in Mg I (518 nm) Images of 1999 Leonid Storm Meteors

    NASA Technical Reports Server (NTRS)

    Taylor, M. J.; Murray, I. S.; Jenniskens, P.

    2000-01-01

    Small meteoric fragments are ejected at significant transverse velocities from some (up to approx. 8%) fast Leonid meteors. We reach this conclusion using low light intensified image measurements obtained during the 1999 Leonid Multi-Instrument Aircraft Campaign. High spatial resolution, narrow band image measurements of the Mg I emission at 518 nm have been used to clearly identify jet-like features in the meteor head that are the same as first observed in white light. We postulate that these unusual structures are caused by tiny meteoroid fragments (containing metallic grains) being rapidly ejected away from the core meteoroid as the constituent glue evaporates. Marked curvature observed in the jet-like filaments suggest that the parent meteoroids are spinning and as the whirling fragments are knocked away by the impinging air molecules, or by grain-grain collisions in the fragment ensemble, they ablate quickly generating an extended area of structured luminosity up to about 1-2 km from the meteoroid center. Fragments with smaller transverse velocity components are thought to be responsible for the associated beading evident in the wake of these unusual Leonid meteors.

  6. MSFC Stream Model Preliminary Results: Modeling Recent Leonid and Perseid Encounters

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; Moser, Danielle E.

    2004-01-01

    The cometary meteoroid ejection model of Jones and Brown (1996b) was used to simulate ejection from comets 55P/Tempel-Tuttle during the last 12 revolutions, and the last 9 apparitions of 109P/Swift-Tuttle. Using cometary ephemerides generated by the Jet Propulsion Laboratory s (JPL) HORIZONS Solar System Data and Ephemeris Computation Service, two independent ejection schemes were simulated. In the first case, ejection was simulated in 1 hour time steps along the comet s orbit while it was within 2.5 AU of the Sun. In the second case, ejection was simulated to occur at the hour the comet reached perihelion. A 4th order variable step-size Runge-Kutta integrator was then used to integrate meteoroid position and velocity forward in time, accounting for the effects of radiation pressure, Poynting-Robertson drag, and the gravitational forces of the planets, which were computed using JPL s DE406 planetary ephemerides. An impact parameter was computed for each particle approaching the Earth to create a flux profile, and the results compared to observations of the 1998 and 1999 Leonid showers, and the 1993 and 2004 Perseids.

  7. STS-87 Payload Specialist Leonid Kadenyuk chats with NASA Administrator Daniel Goldin shortly after

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, chats with NASA Administrator Daniel Goldin shortly after the landing of Columbia at Kennedy Space Center. Looking on is back-up Payload Specialist Yaroslav Pustovyi, also of NSAU. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34- minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott, Kalpana Chawla, Ph.D., and Takao Doi, Ph.D., of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  8. STS-87 P.S. Leonid Kadenyuk of NSAU and Daniel Goldin after landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, greets NASA Administrator Daniel Goldin, at right, as back-up Payload Specialist Yaroslav Pustovyi, also of NSAU, looks on. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D. of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  9. Investigation on spectral character of ELF electromagnetic radiations during Leonid 2009 meteor shower

    NASA Astrophysics Data System (ADS)

    Guha, Anirban; De, Barin Kumar; Choudhury, Abhijit; Roy, Rakesh

    2012-10-01

    There are several reports of simultaneous optical flashes as well as audible sounds called electrophonics during the passage of meteors through the Earth's atmosphere, but the exact physical mechanism behind these phenomena is still poorly understood. Some experiments performed during meteor showers indicate the presence of ELF-VLF electromagnetic waves generated simultaneously with the passage of a meteor, which after suitable transduction are converted into audible sound waves. In this context, the present paper investigates the temporal and spectral character of ELF electromagnetic waves produced during the Leonid meteor shower on 18th November, 2009. A well calibrated broadband GPS locked software receiver was used to perform the experiment at the Department of Physics, Tripura University, India (23.50° N 91.25° E). The analysis of temporal data and dynamic spectrogram reveals distinct electromagnetic pulses in the frequency range of a few Hz to 2 kHz during the predicted time of peak activity of the shower. The spectral character of these pulses is found to be completely different from the spectral signatures originating from lightning discharges. During the peak activity period, the meteor counts using ELF method is found to be around 11,000 meteors hr-1, which is around 137 times more than the worldwide reported visible rate. The observational results are discussed from the viewpoint of deposition of meteoric dust particles and its interaction with ionospheric plasma, leading to emission of electromagnetic waves during the passage of meteors through the Earth's atmosphere.

  10. STS-87 Payload Specialist Leonid Kadenyuk chats with NASA Administrator Daniel Goldin shortly after

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, chats with NASA Administrator Daniel Goldin shortly after the landing of Columbia at Kennedy Space Center. Looking on is back-up Payload Specialist Yaroslav Pustovyi, also of NSAU. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34- minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott, Kalpana Chawla, Ph.D., and Takao Doi, Ph.D., of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  11. STS-87 P.S. Leonid Kadenyuk of NSAU and Daniel Goldin after landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, greets NASA Administrator Daniel Goldin, at right, as back-up Payload Specialist Yaroslav Pustovyi, also of NSAU, looks on. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D. of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  12. Lorentz-Shaped Comet Dust Trail Cross Section from New Hybrid Visual and Video Meteor Counting Technique - Implications for Future Leonid Storm Encounters

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Crawford, Chris; Butow, Steven J.; Nugent, David; Koop, Mike; Holman, David; Houston, Jane; Jobse, Klaas; Kronk, Gary

    2000-01-01

    A new hybrid technique of visual and video meteor observations was developed to provide high precision near real-time flux measurements for satellite operators from airborne platforms. A total of 33,000 Leonids. recorded on video during the 1999 Leonid storm, were watched by a team of visual observers using a video head display and an automatic counting tool. The counts reveal that the activity profile of the Leonid storm is a Lorentz profile. By assuming a radial profile for the dust trail that is also a Lorentzian, we make predictions for future encounters. If that assumption is correct, we passed 0.0003 AU deeper into the 1899 trailet than expected during the storm of 1999 and future encounters with the 1866 trailet will be less intense than. predicted elsewhere.

  13. Lorentz Shaped Comet Dust Trail Cross Section from New Hybrid Visual and Video Meteor Counting Technique - Implications for Future Leonid Storm Encounters

    NASA Astrophysics Data System (ADS)

    Jenniskens, Peter; Crawford, Chris; Butow, Steven J.; Nugent, David; Koop, Mike; Holman, David; Houston, Jane; Jobse, Klaas; Kronk, Gary; Beatty, Kelly

    A new hybrid technique of visual and video meteor observations was developed to provide high precision near real-time flux measurements for satellite operators from airborne platforms. A total of 33,000 Leonids, recorded on video during the 1999 Leonid storm, were watched by a team of visual observers using a video head display and an automatic counting tool. The counts reveal that the activity profile of the Leonid storm is a Lorentz profile. By assuming a radial profile for the dust trail that is also a Lorentzian, we make predictions for future encounters. If that assumption is correct, we passed 0.0003 AU deeper into the 1899 trailet than expected during the storm of 1999 and future encounters with the 1866 trailet will be less intense than predicted elsewhere.

  14. Buoyancy of the ''Y2K'' Persistent Train and the Trajectory of the 04:00:29 UT Leonid Fireball

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Rairden, Rick L.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The atmospheric trajectory is calculated of a particularly well studied fireball and train during the 1999 Leonid Multi-Instrument Aircraft Campaign. Less than a minute after the meteor's first appearance, the train curves into a '2'-shape, which persisted until at least 13 minutes after the fireball. We conclude that the shape results because of horizontal winds from gravity waves with a scale height of 8.3 km at 79-91 km altitude, as well as a westerly wind gradient with altitude. In addition, there is downward drift that affects the formation of loops in the train early on.

  15. Ionospheric effects of the Leonid meteor shower in November 2001 as observed by rapid run ionosondes

    NASA Astrophysics Data System (ADS)

    Maruyama, Takashi; Kato, Hisao; Nakamura, Maho

    2003-08-01

    We operated ionosondes at four stations in a rapid-run mode to obtain ionograms every minute for 102 hours during the period of the Leonid meteor shower in November 2001. Plenty of radio echoes that looked like echo traces produced by sporadic E reflection were seen in the ionograms, and this allowed statistical analysis in a single meteor shower event, including discrimination of the backscattering by meteor trails from reflection by a horizontally stratified sporadic E layer. The radio echoes seen in the ionograms were categorized into three types. The first were spontaneous echoes, which were distributed across a wide range of virtual heights; at times during the period of maximum meteor activity, there was a statistically good correlation among the echoes seen at the four stations. The echoes of this type appear to be produced by Fresnel backscattering from meteor trails. The second were also spontaneous echoes observed during the shower period but persisted for several tens of minutes at the same virtual height as the typical sporadic E layer, and the top frequency of these echoes decayed with time. Echoes of this type are thus attributed to the reflection from a meteor-induced sporadic E patch. Echoes of the last type appeared outside the period of maximum activity of the meteor shower in the same range of virtual heights as the conventional sporadic E layer, and there was no time correlation between the events observed at the four stations. These events are attributed to a periodical increase in fOEs, which is modulated by planetary-wave activity, and have no relation with the meteor shower.

  16. Observations of persistent Leonid meteor trails: 4. Buoyant rise/vortex formation as mechanism for creation of parallel meteor train pairs

    NASA Astrophysics Data System (ADS)

    Zinn, John; Drummond, Jack

    2005-04-01

    In this paper we present numerical computations designed to demonstrate effects associated with the buoyant rise of persistent trails produced by large Leonid meteors in cases where the meteor velocity vector has a large horizontal component. We model the meteor trail as a hot cylindrical volume in an equilibrium atmosphere. The computed results show the hot cylinder first expanding radially and then rising because of buoyancy, while evolving into a pair of counterrotating linear vortices. These line vortex phenomena are offered as an explanation for the otherwise mysterious parallel pairs of trails that are often observed. We also show some high-resolution images of double meteor trails observed during the high Leonid meteor activity of 1998-2002. For the case of the Diamond Ring event we compare computed and measured luminosity profiles for the sodium 589 nm emission and for the red-near IR O2 atmospheric band (O2(b1Σg+) - O2(X3Σg-)) emission.

  17. MSFC Stream Model Preliminary Results: Modeling the 1998-2002 Leonid Encounters and the 1993,1994, and 2004 Perseid Encounters

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Cooke, W. J.

    2004-01-01

    The cometary meteoroid ejection models of Jones (1996) and Crifo (1997) were used to simulate ejection from comets 55P/Tempel-Tuttle during the last 12 revolutions, and the 1862, 1737, and 161 0 apparitions of 1 OSP/Swift-Tuttle. Using cometary ephemerides generated by the JPL HORIZONS Solar System Data and Ephemeris Computation Service, ejection was simulated in 1 hour time steps while the comet was within 2.5 AU of the Sun. Also simulated was ejection occurring at the hour of perihelion passage. An RK4 variable step integrator was then used to integrate meteoroid position and velocity forward in time, accounting for the effects of radiation pressure, Poynting-Robertson drag, and the gravitational forces of the planets, which were computed using JPL's DE406 planetary ephemerides. An impact parameter is computed for each particle approaching the Earth, and the results are compared to observations of the 1998-2002 Leonid showers, and the 1993-1 994 Perseids. A prediction for Earth's encounter with the Perseid stream in 2004 is also presented.

  18. Mission goals of a 1998/1999 Leonid storm Multi-instrument Aircraft Campaign (MAC)

    NASA Astrophysics Data System (ADS)

    Jenniskens, P.; Butow, S.

    1998-04-01

    In November of 1998 (or in 1999 with about equal probability) will be our one chance in a lifetime to anticipate with some certainty the occurrence of a meteor storm. For a period of up to 2 hours, rates are expected to increase above 1 meteor per second for a naked eye observer. At that time, Earth passes through the outer regimes of the dust trail of comet 55P/Tempel-Tuttle. The high meteor flux offers unprecedented precision in characterizing the dust trail in terms of spatial and particle size distributions of dust grains and allows the measurement of composition, morphology and orbits of individual cometary grains relatively soon after ejection from the comet. By using the Earth's atmosphere as a detector for the dust trains, grains are sampled over a wide mass range, from the typical grain size of zodiacal dust (40 - 200 micron) up until the rare boulders that can still be lifted off the comet nucleus.

  19. Mission goals of a 1998/1999 Leonid storm Multi-instrument Aircraft Campaign (MAC)

    NASA Technical Reports Server (NTRS)

    Jenniskens, P.; Butow, S.

    1998-01-01

    In November of 1998 (or in 1999 with about equal probability) will be our one chance in a lifetime to anticipate with some certainty the occurrence of a meteor storm. For a period of up to 2 hours, rates are expected to increase above 1 meteor per second for a naked eye observer. At that time, Earth passes through the outer regimes of the dust trail of comet 55P/Tempel-Tuttle. The high meteor flux offers unprecedented precision in characterizing the dust trail in terms of spatial and particle size distributions of dust grains and allows the measurement of composition, morphology and orbits of individual cometary grains relatively soon after ejection from the comet. By using the Earth's atmosphere as a detector for the dust trains, grains are sampled over a wide mass range, from the typical grain size of zodiacal dust (40 - 200 micron) up until the rare boulders that can still be lifted off the comet nucleus.

  20. The 1996 Leonid shower as studied with a potassium lidar: Observations and inferred meteoroid sizes

    NASA Astrophysics Data System (ADS)

    Höffner, Josef; von Zahn, Ulf; McNeil, William J.; Murad, Edmond

    1999-02-01

    We report on the observation and analysis of meteor trails that are detected by ground-based lidar tuned to the D1 fine structure line of K. The lidar is located at Kühlungsborn, Germany. The echo profiles are analyzed with a temporal resolution of about 1 s and altitude resolution of 200 m. Identification of meteor trails in the large archive of raw data is performed with help of an automated computer search code. During the peak of the Lenoid meteor shower on the morning of November 17, 1996, we observed seven meteor trails between 0245 and 0445 UT. Their mean altitude was 89.0 km. The duration of observation of individual trails ranges from 3 s to ~30 min. We model the probability of observing a meteor trail by ground-based lidar as a function of both altitude distribution and duration of the trails. These distributions depend on the mass distribution, entry velocity, and entry angle of the meteoroids, on the altitude-dependent chemical and dynamical lifetimes of the released K atom, and on the absolute detection sensitivity of our lidar experiment. From the modeling, we derive the statistical likelihood of detection of trails from meteoroids of a particular size. These bracket quite well the observed trails. The model also gives estimates of the probable size of the meteoroids based on characteristics of individual trails.

  1. 76 FR 21743 - Indigo Logistics, LLC, Liliya Ivanenko, and Leonid Ivanenko-Possible Violations of Section 19 of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-18

    ... Shipping Act of 1984 and the Commission's Regulations; Order of Investigation and Hearing AGENCY: Federal... Shipping Act of 1984 and the Commission's Regulations at 46 CFR part 515. Acting pursuant to Section 11 of... Section 19 of the Shipping Act of 1984 are found, civil penalties should be assessed against Indigo...

  2. Singular Value Spectrum Based Detection and Estimation of Non-Stationary Underwater Acoustic Signals and Their Statistical Modelling by Approximation.

    DTIC Science & Technology

    1992-03-01

    APPROXIMATION March 1992 Professors Nenad M Marinovic and Leonid Roytman Department of Electrical Engineering The City College of The City University...Non-Stationary . Underwater Acous’ic Signals and Their Statistical Modelling by Approximation W -,d, s r Nenad M. Marinovic and Leonid Roytman

  3. CUE - B-STIC, Kadenyuk pollinates Brassica rapa plants

    NASA Image and Video Library

    1998-01-05

    STS087-332-034 (19 November – 5 December 1997) --- On the Space Shuttle Columbia's middeck, Leonid Kadenyuk, Ukrainian payload specialist, works with the Brassica Rapa plants being grown for the Collaborative Ukrainian Experiment (CUE). Leonid Kadenyuk joined five astronauts for 16-days in Earth-orbit in support of the United States Microgravity Payload 4 (USMP-4) mission.

  4. Dust Acoustic Mode Manifestations in Earth's Dusty Ionosphere

    SciTech Connect

    Kopnin, S.I.; Popel, S.I.

    2005-10-31

    Dust acoustic mode manifestations in the dusty ionosphere are studied. The reason for an appearance of the low-frequency radio noises associated with such meteor fluxes as Perseids, Orionids, Leonids, and Gemenids is determined.

  5. 73X Faster Than a Speeding Bullet

    NASA Image and Video Library

    On Nov. 17, 2011, a NASA camera in Tullahoma, Tenn., saw a Leonid meteor -- moving 73 times faster than a bullet fired from an M-16 rifle -- as it burned up 71 miles above Nolensville, Tenn., at an...

  6. Virtual Combat Vehicle Experimentation for Duty Cycle Measurement

    DTIC Science & Technology

    2008-04-01

    Amethyst Leonid Loon Perseids ESS ESS RACK MC2 TMBS Rack SCRAMNet Interface SCRAMNet Figure 8. Computer and network architecture of the DCE3 simulator as...Inc. (RTI) [8]. It was used to seamlessly integrate the main processes on Emerald, Leonid, Amethyst , and Pyrite. Emerald, a quad-core Windows XP...SCRAMNet® interface. Amethyst ran the stealth viewer which gives a “parasail” view of the primary vehicle (using SimCreator’s IG). Pyrite runs sim

  7. The danger to satellites from meteor storms

    NASA Astrophysics Data System (ADS)

    Beech, M.; Brown, P.; Jones, J.; Webster, A. R.

    During past meteor storms impact probabilities of between 1 and 0.01 percent have be realized per 50m^2 of exposed surface area at altitudes corresponding to both GEO and LEO. The most likely meteoroid stream to yield a storm in the near future is that of the Leonids. Numerical simulations of the orbital evolution of hypothetical Leonid stream meteoroids suggest that storms may occur in the years 1999 and 2000.

  8. Virtual Combat Vehicle Experimentation for Duty Cycle Measurement

    DTIC Science & Technology

    2008-04-16

    GUNNER STATION Telex Console 1 3 7 . 1 2 8 . 1 1 CONTROL ROOM Emerald Pyrite Amethyst Leonid Loon Perseids ESS ESS RACK MC2 TMBS Rack SCRAMNet Interface...subnets yUDP/IP y Fiber optic deterministic network. Emerald Leonid Amethyst UDP I/F to Simrecorder 1) DIS I/F 2) Audio 1) OE I/F 2) LongHaul Dynamics

  9. Constraining the Physical Properties of Meteor Stream Particles by Light Curve Shapes Using the Virtual Meteor Observatory

    NASA Technical Reports Server (NTRS)

    Koschny, D.; Gritsevich, M.; Barentsen, G.

    2011-01-01

    Different authors have produced models for the physical properties of meteoroids based on the shape of a meteor's light curve, typically from short observing campaigns. We here analyze the height profiles and light curves of approx.200 double-station meteors from the Leonids and Perseids using data from the Virtual Meteor Observatory, to demonstrate that with this web-based meteor database it is possible to analyze very large datasets from different authors in a consistent way. We compute the average heights for begin point, maximum luminosity, and end heights for Perseids and Leonids. We also compute the skew of the light curve, usually called the F-parameter. The results compare well with other author's data. We display the average light curve in a novel way to assess the light curve shape in addition to using the F-parameter. While the Perseids show a peaked light curve, the average Leonid light curve has a more flat peak. This indicates that the particle distribution of Leonid meteors can be described by a Gaussian distribution; the Perseids can be described with a power law. The skew for Leonids is smaller than for Perseids, indicating that the Leonids are more fragile than the Perseids.

  10. PF191012 Myszyniec - highest Orionid meteor ever recorded

    NASA Astrophysics Data System (ADS)

    Olech, A.; Żołaḑek, P.; Wiśniewski, M.; Fietkiewicz, K.; Maciejewski, M.; Tymiński, Z.; Krzyżanowski, T.; Krasnowski, M.; Kwinta, M.; Myszkiewicz, M.; Polakowski, K.; Zarȩba, P.

    2013-09-01

    On the night of Oct. 18/19, 2012, at 00:23 UT, a -14.7 mag Orionid fireball occurred over northeastern Poland. The precise orbit and atmospheric trajectory of the event are presented, based on the data collected by five video stations and one photographic Polish Fireball Network station. The beginning height of the meteor is 168.4 ± 0.6 km, which makes the PF191012 Myszyniec fireball the highest ever observed, well-documented meteor not belonging to the Leonid shower. The ablation became the dominant source of light of the meteor at a height of around 115 km. The thermalization of sputtered particles is suggested to be the source of radiation above that value. The transition height of 115 km is 10-15 km below the transition heights derived for Leonids and might suggest that the material of Leonids is more fragile and probably has smaller bulk density than that of Orionids.

  11. Meteoroids and Meteor Storms: A Threat to Spacecraft

    NASA Technical Reports Server (NTRS)

    Anderson, B. Jeffrey

    1999-01-01

    Robust system design is the best protection against meteoroid damage. Impacts by small meteoroids are common on satellite surfaces, but impacts by meteoroids large enough to damage well designed systems are very rare. Estimating the threat from the normal meteoroid environment is difficult. Estimates for the occasional "storm" are even more uncertain. Common sense precautions are in order for the 1999 Leonids, but wide-spread catastrophic damage is highly unlikely. Strong Leonid showers are also expected in 2000 and 2001, but these pose much less threat than 1999.

  12. Kadenyuk sleeps strapped to the middeck wall

    NASA Image and Video Library

    1997-11-28

    STS087-323-030 (19 November – 5 December 1997) --- Ukrainian payload specialist Leonid K. Kadenyuk blocks out the world and much more as he sleeps on the mid-deck of the Earth-orbiting Space Shuttle Columbia. Kadenyuk joined five NASA astronauts for 16 days aboard Columbia in support of the United States Microgravity Payload (USMP) mission.

  13. USSR Report: Political and Sociological Affairs

    DTIC Science & Technology

    2007-11-02

    awarded twice over the pilots Talgat Begeldinov, Sergey Luganskiy, Leonid Beda, and Ivan Pavlov . Manshuk Mametova and Aliya Moldagulova--the first Eastern...CPSU Obkom. A.V. Pavlov , who previously served as first secretary of the Volosovskiy Party Raykom, was approved as head of the Agriculture and Food

  14. SKYLAB (SL)-2 POSTFLIGHT - COMMEMORATIVE PLAQUES PRESENTATION - CA

    NASA Image and Video Library

    1973-07-19

    S73-30889 (June 1973) --- Leonid I. Breznev, General Secretary of the Communist Party, Union of Soviet Socialist Republics, and President Richard M. Nixon, during ceremonies at the Western White House in San Clemente, California, examine plaques presented by Skylab astronauts Charles Conrad Jr., center; Joseph P. Kerwin, second from right; and Paul J. Weitz, left. Photo credit: NASA

  15. The First Confirmed Videorecordings of Lunar Meteor Impacts

    NASA Technical Reports Server (NTRS)

    Dunham, D. W.; Cudnik, B.; Palmer, D. M.; Sada, P. V.; Melosh, J.; Beech, M.; Pellerin, L.; Asher, D.; Frankenberger R.; Venable R.

    2000-01-01

    North American observers recorded at least six meteors striking the Moon's surface during the Leonid meteor shower on 1999 Nov. 18. Each meteor produced a flash that was recorded from at least two separate locations, marking the first confirmed lunar meteor impacts.

  16. The Politics of Drug Trafficking in Mexican and Mexico-Related Narconovelas

    ERIC Educational Resources Information Center

    Palaversich, Diana

    2006-01-01

    This essay traces the emergence of the Mexican and Mexico-related narconovela. It examines perspectives on drug trafficking and traffickers expressed in novels by Elmer Mendoza, Leonides Alfaro, Gerardo Cornejo, Homero Aridjis, Arturo Perez-Reverte, and Paul Flores. The variety of positions taken refutes the tendency of the Mexican mainstream…

  17. Perspectivas Pedagogicas. Documentos-Ponencias Y Ensayos Proyecto Teacher Corps, Ciclo XII (Pedagogical Perspectives. Documents, Papers and Essays, Teacher Corps Project, Cycle XII).

    ERIC Educational Resources Information Center

    Albino, Isidra, Ed.; Davila, Sonia, Ed.

    The purpose of this book is to stimulate ideas leading to a sharing of approaches, strategies, and methodologies applicable to the education of Puerto Ricans. Following introductory material, 18 papers are presented, the first 10 of which are in Spanish. Titles and authors are: (1) "El maestro que Puerto Rico necesita," Leonides Santos…

  18. The Politics of Drug Trafficking in Mexican and Mexico-Related Narconovelas

    ERIC Educational Resources Information Center

    Palaversich, Diana

    2006-01-01

    This essay traces the emergence of the Mexican and Mexico-related narconovela. It examines perspectives on drug trafficking and traffickers expressed in novels by Elmer Mendoza, Leonides Alfaro, Gerardo Cornejo, Homero Aridjis, Arturo Perez-Reverte, and Paul Flores. The variety of positions taken refutes the tendency of the Mexican mainstream…

  19. Onboard photo: Astronauts at work

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Onboard Space Shuttle Columbia (STS-87) mid-deck, Leonid Kadenyuk, Ukrainian payload specialist, works with the Brassica rapa plants being grown for the Collaborative Ukrainian Experiment (CUE). Kadenyuk joined five astronauts for 16-days in Earth-orbit in support of the United States Microgravity Payload 4 (USMP-4) mission.

  20. Modelling of the new formation structures in the near space.

    PubMed

    Kulikova, N V; Pivnenko, E A

    1992-01-01

    Complex numerical model of young meteor stream formation taking into account reactive deceleration of cometary nucleus and its form change in the process of stream formation is discussed. The model made it possible to predict the existence of fine and superfine structures for young meteor streams, the characteristics of which agree with the observational data on the Draconid and Leonid meteor showers.

  1. Microgravity

    NASA Image and Video Library

    1997-11-19

    Onboard Space Shuttle Columbia (STS-87) mid-deck, Leonid Kadenyuk, Ukrainian payload specialist, works with the Brassica rapa plants being grown for the Collaborative Ukrainian Experiment (CUE). Kadenyuk joined five astronauts for 16-days in Earth-orbit in support of the United States Microgravity Payload 4 (USMP-4) mission.

  2. Onboard photo: Astronauts at work

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Onboard Space Shuttle Columbia (STS-87) mid-deck, Leonid Kadenyuk, Ukrainian payload specialist, works with the Brassica rapa plants being grown for the Collaborative Ukrainian Experiment (CUE). Kadenyuk joined five astronauts for 16-days in Earth-orbit in support of the United States Microgravity Payload 4 (USMP-4) mission.

  3. Tools for Large Graph Mining

    DTIC Science & Technology

    2005-06-01

    Edo , Leonid, Anya, Jason, and all others for their help and insights; and finally to Krishna, old friend, for his constant “Are you done yet?” which...17 3.4.1 (Q1) Accuracy of dynamical system ...4.4.1 (Q1) Accuracy of the dynamical system . . . . . . . . . . . . . . . . . . . 33 4.4.2 (Q2) Accuracy of the threshold condition

  4. Perspectivas Pedagogicas. Documentos-Ponencias Y Ensayos Proyecto Teacher Corps, Ciclo XII (Pedagogical Perspectives. Documents, Papers and Essays, Teacher Corps Project, Cycle XII).

    ERIC Educational Resources Information Center

    Albino, Isidra, Ed.; Davila, Sonia, Ed.

    The purpose of this book is to stimulate ideas leading to a sharing of approaches, strategies, and methodologies applicable to the education of Puerto Ricans. Following introductory material, 18 papers are presented, the first 10 of which are in Spanish. Titles and authors are: (1) "El maestro que Puerto Rico necesita," Leonides Santos…

  5. Meteor Outbursts and Storms from the Spacecraft Hazard Perspective

    NASA Technical Reports Server (NTRS)

    Cooke, William; Moser, Danielle; Suggs, Rob

    2004-01-01

    The recent Leonid meteor storms have propelled meteor shower forecasting from an idea into the realm of practical application, invoked several times per year by numerous spacecraft. This paper will describe shower activity predictions, which give zenith hourly rate (ZHR) as a function of time, and how these are translated into spacecraft risks. Common spacecraft meteor shower mitigation strategies will also be discussed, and the important issue as to when to implement such operations considered. It should be noted that, while the recent meteor storms did not result in the loss of a vehicle, there were a few spacecraft anomalies attributed to Leonid strikes, and the nature of these will be commented upon. Finally, we assess the current state of the art in shower forecasting, and take a look "down the road" at some possible outbursts in the near future.

  6. KSC-97PC1684

    NASA Image and Video Library

    1997-11-19

    The president of the Ukraine, Leonid Kuchma, is flanked by Payload Specialist Leonid Kadenyuk, at left, and backup Payload Specialist Yaroslav Pustovyi, at right, both of the National Space Agency of Ukraine, during prelaunch activities leading up to the scheduled Nov. 19 launch of STS-87. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia's middeck and will feature an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment with Kadenyuk in space. Kadenyuk will be flying his first Shuttle mission on STS-87

  7. KSC-97PC1685

    NASA Image and Video Library

    1997-11-19

    The president of the Ukraine, Leonid Kuchma, shakes hands with Payload Specialist Leonid Kadenyuk, at right, as backup Payload Specialist Yaroslav Pustovyi, both of the National Space Agency of Ukraine, looks on during prelaunch activities leading up to the scheduled Nov. 19 launch of STS-87. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia's middeck and will feature an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment with Kadenyuk in space. Kadenyuk will be flying his first Shuttle mission on STS-87

  8. Stratospheric Sampling and In Situ Atmospheric Chemical Element Analysis During Meteor Showers: A Resource Study

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    2000-01-01

    Resources studies for asteroidal mining evaluation have depended historically on remote sensing analysis for chemical elements. During the November 1998 Leonids meteor shower, a stratospheric balloon and various low-density capture media were used to sample fragments from Comet Tempel-Tuttle debris during a peak Earth crossing. The analysis not only demonstrates how potential sampling strategies may improve the projections for metals or rare elements in astromining, but also benchmarks materials during low temperature (-60 F), high dessication environments as seen during atmospheric exposure. The results indicate high aluminum, magnesium and iron content for various sampled particles recovered, but generalization to the sporadic meteors expected from asteroidal sources will require future improvements in larger sampling volumes before a broad-use strategy for chemical analysis can be described. A repeat of the experimental procedure is planned for the November 1999 Leonids' shower, and various improvements for atmospheric sampling will be discussed.

  9. Meteor Outbursts and Storms from the Spacecraft Hazard Perspective

    NASA Technical Reports Server (NTRS)

    Cooke, William; Moser, Danielle; Suggs, Rob

    2004-01-01

    The recent Leonid meteor storms have propelled meteor shower forecasting from an idea into the realm of practical application, invoked several times per year by numerous spacecraft. This paper will describe shower activity predictions, which give zenith hourly rate (ZHR) as a function of time, and how these are translated into spacecraft risks. Common spacecraft meteor shower mitigation strategies will also be discussed, and the important issue as to when to implement such operations considered. It should be noted that, while the recent meteor storms did not result in the loss of a vehicle, there were a few spacecraft anomalies attributed to Leonid strikes, and the nature of these will be commented upon. Finally, we assess the current state of the art in shower forecasting, and take a look "down the road" at some possible outbursts in the near future.

  10. Generation of infrasonic waves by low-frequency dust acoustic perturbations in the Earth's lower ionosphere

    SciTech Connect

    Kopnin, S. I.; Popel, S. I.

    2008-06-15

    It is shown that, during Perseid, Geminid, Orionid, and Leonid meteor showers, the excitation of low-frequency dust acoustic perturbations by modulational instability in the Earth's ionosphere can lead to the generation of infrasonic waves. The processes accompanying the propagation of these waves are considered, and the possibility of observing the waves from the Earth's surface is discussed, as well as the possible onset of acoustic gravitational vortex structures in the region of dust acoustic perturbations. The generation of such structures during Perseid, Geminid, Orionid, and Leonid meteor showers can show up as an increase in the intensity of green nightglow by an amount on the order of 10% and can be attributed to the formation of nonlinear (vortex) structures at altitudes of 110-120 km.

  11. Stratospheric Sampling and In Situ Atmospheric Chemical Element Analysis During Meteor Showers: A Resource Study

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    2000-01-01

    Resources studies for asteroidal mining evaluation have depended historically on remote sensing analysis for chemical elements. During the November 1998 Leonids meteor shower, a stratospheric balloon and various low-density capture media were used to sample fragments from Comet Tempel-Tuttle debris during a peak Earth crossing. The analysis not only demonstrates how potential sampling strategies may improve the projections for metals or rare elements in astromining, but also benchmarks materials during low temperature (-60 F), high dessication environments as seen during atmospheric exposure. The results indicate high aluminum, magnesium and iron content for various sampled particles recovered, but generalization to the sporadic meteors expected from asteroidal sources will require future improvements in larger sampling volumes before a broad-use strategy for chemical analysis can be described. A repeat of the experimental procedure is planned for the November 1999 Leonids' shower, and various improvements for atmospheric sampling will be discussed.

  12. Characterization of Atmospheric Turbulence Effects Over 149 km Propagation Path using Multi-Wavelength Laser Beacons

    DTIC Science & Technology

    2010-09-01

    USA Svetlana L . Lachinova Institute for Systems Research, University of Maryland, College Park, Maryland 20742, USA Leonid A . Beresnev...0 0( , , , , )nF C l L z h is a factor represented here as a function of the propagation path characteristics (distance z and elevation h) and the...pp. 7099–7109, 2007. [16] M. S. Belen’kii, E. Cuellar , K. A . Hughes, and V. A . Rye, “Preliminary experimental evidence of anisotropy of turbulence

  13. Herrick, Edward Claudius (1811-62)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Bookseller and librarian, born in New Haven, CT, self-educated by association with Yale University academics, and observer of the 9 August 1837 meteor shower, which he identified as the Perseids. With the Leonids in mind (after a brilliant display in November 1833 they proved to be an annual shower, the first identified), Herrick found other August records of meteor showers. In 1839 he confirmed...

  14. JPRS Report, China.

    DTIC Science & Technology

    1989-05-25

    26th Soviet Party Congress in 1981, Leonid Brezhnev said that attempts to surpass the adver - sary in an arms race, or the expectation of winning...manner, causing some side effects which have adversely affected to a certain extent the stable growth of agricultural production. A solution to...bling paratyphoid fever occurred that was attributed to the use of unsafe vaccine . Pharmacological testing of the same batch of vaccine for

  15. Radioactivity and Environmental Security in the Oceans: New Research and Policy Priorities in the Arctic and North Atlantic

    DTIC Science & Technology

    1993-06-09

    wreme of form. Lv 401 2. Comrpiefe teons I and2. B. REPORg TITLE AND/OR NUMBER(• ,- /’fCk+ at-.v,• ,ý 0-4 •.,•n,•1 . 3. Attachformnto reports ptilfel"YVL...Washington, DC 20375 Tel: 202-767-5692 Fax: 202-767-3709 83 Leonid Polyak Byrd Polar Research Center Ohio State University 1090 Carmack Road Columbus, OH

  16. Integrating Language and Cognition in Grounded Adaptive Agents

    DTIC Science & Technology

    2008-11-21

    session on “Modelling Language Acquisition and Evolution” at the IJCNN06 conference. Cangelosi was the chair of the Special Session on “Modelling... Language Acquisition and Evolution” held on July 2006 at the IJCNN2006 conference. The session was organized in collaboration with Dr. Leonid Perlovsky...learning during language acquisition . 5. Webpage for grant Tikhanoff has designed a web page dedicated to the project. This includes an overview of

  17. The Emergence of Compositional Communication in a Synthetic Ethology Framework

    DTIC Science & Technology

    2005-08-12

    differentiation in the Modeling Field Theory framework 26 Language acquisition and category discrimination in the Modeling Field...Fontanari and Leonid I. Perlovsky, " Language acquisition and category discrimination in the Modeling Field Theory framework", Proceedings of the...somehow from its parent is ft = 1 — (1 — u)2. Henceforth, we will refer to [i as the proba- bility of error in language acquisition . To facilitate

  18. Theoretical and Observational Studies of Meteor Interactions with the Ionosphere

    DTIC Science & Technology

    2006-06-01

    Spaceborne Ultraviolet 251-384 nm Spectroscopy of a Meteor During the 1997 Leonid Shower , Meteorites and Planetary Science, 37. Jones, W., 1997...RTO-MP-IST-056 12 - 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Theoretical and Observational Studies of Meteor Interactions with the...ABSTRACT An intense flux of small-mass meteors has been seen in large-aperture radar scattering for many years. At high altitudes, these meteoroids

  19. Archive of radar observations of meteors in Tomsk in 1965-1966. (Russian Title: Архив радиолокационных наблюдений метеоров в Томске в 1965-1966 гг.)

    NASA Astrophysics Data System (ADS)

    Ryabova, G. O.

    2010-12-01

    The archive of data of radar observations of Geminid, Quadrantid, Daytime Arietid, Perseid, Ursid, Lyrid, Orionid and Leonid meteor showers in Tomsk in 1965-1966 is described. In certain cases registrations of the sporadic background before and after a shower exist. Primary data of echo registrations contain time of a registration, distance, duration and amplitude of an echo, allowing to obtain corresponding distributions essential for calculation of the incident flux density of meteors. Work on the archive digitization has been started.

  20. Meteor Beliefs Project: Seven years and counting

    NASA Astrophysics Data System (ADS)

    McBeath, A.; Drobnock, G. J.; Gheorghe, A. D.

    2010-04-01

    The Meteor Beliefs Project's seventh anniversary is celebrated with an eclectic mixture of meteor beliefs from the 1799 Leonids in Britain, the folkloric link between meteors and wishing in some Anglo-American sources, how a meteoric omen came to feature in Nathaniel Hawthorne's 1850 novel The Scarlet Letter, and a humorous item from the satirical magazine Punch in 1861, all helping to show how meteor beliefs can be transformed by different parts of society.

  1. Vague-to-Crisp Dynamics of Percept Formation Modeled as Operant (Selectionist) Process

    DTIC Science & Technology

    2013-04-04

    framework with cognitive processing and the intentional neurodynamic cycle. Vague-to-crisp dynamics of percept formation m Approved for public...13: Supplementary Note © 2013 . Published in Cognitive Neurodynamics , Vol. Ed. 0 8, (1) (2013), (, (1). DoD Components reserve a royalty-free...operant (selectionist) process Roman Ilin, J un Zhang, Leonid Perlovsky & Robert Kozma Cognitive Neurodynamics ISSN 1871 4080 Cogn Neurodyn

  2. Cognitively Inspired Neural Network for Situation Recognition

    DTIC Science & Technology

    2010-01-14

    Neurodynamics of Higher-Level Cognition and Consciousness, Eds. Perlovsky, 1.I., Kozma, R. Springer Verlag, Heidelberg, Germany. Perlovsky, L.I., Deming...Perlovsky L. I., Kozma R. (2007) Eds. Neurodynamics of Higher-Level Cognition and Consciousness. Heidelberg, Germany: Springer-Verlag. Perlovsky, L.1...AFRL-RY -HS-TR-20 10-0028 Cognitively Inspired Neural Network for Situation Recognition Roman Ilin and Leonid Perlovsky AFRURYHE 80 Scott Drive

  3. Homeostatic and Circadian Modulation of Cognition: Integrating Mathematical and Computational Modeling Approaches

    DTIC Science & Technology

    2012-08-20

    Leonid V. Kalachev, Ph.D. (University of Montana, not supported on grant) Daniel J. Mollicone, Ph.D. ( Pulsar Informatics, Inc., not supported on grant...project to Pulsar Informatics, Inc., who are providing an implementation suitable for integration with crew rostering to the U.S. Navy (key...individuals involved: Daniel Mollicone, Ph.D. and Mike Stubna, Ph.D. of Pulsar Informatics, Inc.).  We transitioned a numerical library for the mathematical

  4. Soviet Foreign Policy in the Middle East: Internal and External Determinants.

    DTIC Science & Technology

    1987-06-01

    Soviet policies, the’limits of Soviet ability to control a client state, and the difficulties Moscow mght encounter in subsequent client...Leonid Brezhnev, was the primary proponent of Soviet detente policy with the United States. The views expressed by Pravda during this period stress the...generals and adhirals may express their own particular views - does not correspond with the actualit of the tight Party-military control that is exercised

  5. The Soviet Quest for Regional Security Studies of Foreign Policy Decision-Making in the USSR.

    DTIC Science & Technology

    1986-09-01

    leaders also dwelt upon the Afghanistan crisis. It was pointed out that imperialist infiltration was the main reason for the Soviet actions in Afghanistan...continued and enlarged Western action . This reasoning was followed up by Leonid Brezhnev during this major report to the Twenty-Sixth Congress of the...Watson. 1 The reasons for his security obsession are obvious. Russia lacked natural, defensible borders both to the West and to the East. Frequent

  6. ESA's experts are ready for a storm of comet dust

    NASA Astrophysics Data System (ADS)

    1998-11-01

    Minute grains of dust create the glowing heads and tails that make comets famous. A trail of dust traces the orbit of each comet, and when the Earth encounters a comet trail the result is a meteor shower. Comet Tempel-Tuttle has just refreshed its dust trail on a visit to the Sun's vicinity, which it makes every 33 years. The Leonids approach the Earth from the direction of the constellation Leo. As a precaution, the Hubble Space Telescope will turn its back on Leo for ten hours around the predicted peak of the Leonid event, which is at about 20:30 CET on 17 November. Astronomers will take the opportunity to look for undiscovered galaxies in the opposite direction in the sky. Any disturbances caused to the 11.6-tonne Hubble spacecraft by the Leonid dust impacts will be recorded for analysis by dust specialists. One of the teams chosen for this study includes ESA and UK scientists and is headed by John Zarnecki of the University of Kent. Zarnecki comments: "It seems like doing an experiment with the crown jewels. But Hubble is a fantastically accurate star pointer, so we should detect wobbles due to quite small impacts. We hope to check our theories about the numbers of grains of different masses. But I'd hate to see any harm come to Hubble," Zarnecki adds. "Or any other spacecraft for that matter." Taking account of the risk to spacecraft This year Comet Tempel-Tuttle passed within 1.2 million kilometres of the Earth's orbit, which is very near by astronomical standards. Similar close encounters have produced widely differing results in the past. In 1932 the count of visible meteors in the Leonids reached an unremarkable rate of 240 per hour, compared with a normal background of about 10-20 sporadic meteors per hour at quiet times. Yet in 1966 the count-rate for the Leonids was 15,000 per hour, or 4 per second, and some observers reported even higher rates. If the rate is again 15,000 per hour, a spacecraft presenting a target of 10 square metres to the Leonid

  7. Latin America Report

    DTIC Science & Technology

    1985-07-25

    Buenos Aires strongman Herminio Iglesias were chosen as the party’s top authorities there. Many complaints were voiced about some of the procedures...Vicente Leonides Saadi, who left the Rio Hondo ranks and reached an agreement with Lorenzo Miguel and Herminio Iglesias to hold "a plenary meeting to...Bercovich Rodriguez agreed a few days later to the automatic convocation of the congress that Saadi, Iglesias and Miguel were requesting and that, according

  8. Ancient Chinese Observations and Modern Cometary Models

    NASA Technical Reports Server (NTRS)

    Yeomans, D. K.

    1995-01-01

    Ancient astronomical observations, primarily by Chinese, represent the only data source for discerning the long-term behavior of comets. These sky watchers produced astrological forecasts for their emperors. The comets Halley, Swift-Tuttle, and Tempel-Tuttle have been observed for 2000 years. Records of the Leonid meteor showers, starting from A.D.902, are used to guide predictions for the 1998-1999 reoccurrence.

  9. Lagrangian Turbulence and Transport in Semi-Enclosed Basins and Coastal Regions

    DTIC Science & Technology

    2003-09-30

    involved in the application of the assimilation methods ; Leonid Piterbarg (USC) in the mathematical formulation of the method; Milena Veneziani (RSMAS...MPO) in the analysis of Lagrangian data; Mike Chin (RSMAS/MPO) in the comparison of the assimilation methods . WORK COMPLETED 1) Application of...Lagrangian statistics even in presence of coherent structures. TRANSITIONS Lagrangian data assimilation methods are planned to be used in the

  10. The Heavens on Fire

    NASA Astrophysics Data System (ADS)

    Littmann, Mark

    1998-10-01

    Meteor succeeded meteor in such rapid succession that it was impossible to count them; at times the sky seemed full of them, and the earth was illuminated as with a morning light. Eye-witness accounts such as this, and every spectacular detail of the Leonids, the greatest meteor showers of all, can be found in the acclaimed The Heavens on Fire. In this volume, author Mark Littmann vividly tells the history of meteors, and especially the Leonids, whose terrifying beauty established meteor science. He traces the history and mythology of meteors, profiles the fascinating figures whose discoveries advanced the field, and explores how meteors have changed the course of life on Earth. Crisp illustrations capture the excitement of past meteor showers and help elucidate important concepts. The returning Leonids are now reaching their peak with great activity expected in 1999 and 2000. For all those who wish to take part in this rare experience, Littmann offers advice on how and where to find the best view. Filled with practical tips, clear explanations, and descriptions of a sight that more than one observer has called "brilliant beyond conception," The Heavens on Fire will delight every reader. Mark Littmann teaches astronomy at the University of Tennessee. His previous books include Comet Halley: Once in a Lifetime and Planets Beyond: Discovering the Outer Solar System. Both books were chosen by the Astronomical Society of the Pacific as Astronomy Books of the Year.

  11. Analysis of historical meteor and meteor shower records: Korea, China, and Japan

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Jin; Park, Changbom; Park, Myeong-Gu

    2005-05-01

    We have compiled and analyzed historical Korean meteor and meteor shower records in three Korean official history books, Samguksagi which covers the three Kingdoms period (57 B.C.-A.D. 935), Goryeosa of Goryeo dynasty (A.D. 918-1392), and Joseonwangjosillok of Joseon dynasty (A.D. 1392-1910). We have found 3861 meteor and 31 meteor shower records. We have confirmed the peaks of Perseids and an excess due to the mixture of Orionids, north-Taurids, or Leonids through the Monte Carlo test. The peaks persist from the period of Goryeo dynasty to that of Joseon dynasty, for almost one thousand years. Korean records show a decrease of Perseids activity and an increase of Orionids/north-Taurids/Leonids activity. We have also analyzed seasonal variation of sporadic meteors from Korean records. We confirm the seasonal variation of sporadic meteors from the records of Joseon dynasty with the maximum number of events being roughly 1.7 times the minimum. The Korean records are compared with Chinese and Japanese records for the same periods. Major features in Chinese meteor shower records are quite consistent with those of Korean records, particularly for the last millennium. Japanese records also show Perseids feature and Orionids/north-Taurids/Leonids feature, although they are less prominent compared to those of Korean or Chinese records.

  12. Topography and Dynamics of Synthesis of Structural Proteins of Newcastle Disease Virus

    PubMed Central

    Zhdanov, Victor M.; Azadova, Nonna B.; Uryvayev, Leonid V.

    1966-01-01

    Zhdanov, Victor M. (The D. I. Ivanovsky Institute of Virology, Moscow, USSR), Nonna B. Azadova, and Leonid V. Uryvayev. Topography and dynamics of synthesis of structural proteins of Newcastle disease virus. J. Bacteriol. 91:1902–1906. 1966.—Newcastle disease virus S and V antigens are synthesized in the cytoplasm, as revealed by the immunofluorescence method. In some experiments, S antigen was found also in the nucleoli. Actinomycin D moderately decreased the titer of infectious virus and V antigen and accelerated the time of appearance of mature virus. Proflavine sharply decreased the synthesis of both antigens and the release of mature virus. Images PMID:5327911

  13. Conjoined twins: scientific cinema and Pavlovian physiology.

    PubMed

    Krementsov, Nikolai

    2015-01-01

    Through the lens of a 1957 documentary film, "Neural and humoral factors in the regulation of bodily functions (research on conjoined twins)," produced by the USSR Academy of Medical Sciences, this essay traces the entwined histories of Soviet physiology, studies of conjoined twins and scientific cinema. It examines the role of Ivan Pavlov and his students, including Leonid Voskresenkii, Dmitrii Fursikov and Petr Anokhin, in the development of "scientific film" as a particular cinematographic genre in Soviet Russia and explores numerous puzzles hidden behind the film's striking visuals. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  14. KSC-97PC1688

    NASA Image and Video Library

    1997-11-18

    STS-87 Commander Kevin Kregel poses with his wife, Jeannie Kregel, in front of Kennedy Space Center's Launch Pad 39B during final prelaunch activities leading up to the scheduled Nov. 19 liftoff. The other STS-87 crew members are Pilot Steven Lindsey; Mission Specialists Kalpana Chawla, Ph.D., Winston Scott, and Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite

  15. Optical detection of meteoroidal impacts on the Moon

    PubMed

    Ortiz; Sada; Bellot Rubio LR; Aceituno; Aceituno; Gutierrez; Thiele

    2000-06-22

    Impacts of meteoroids on the Moon should cause detectable optical flashes, but the population of objects that are big enough is very low, and hitherto no unambiguous impact flashes have been recorded. The flux of meteoroids associated with the Leonid meteor shower of 18 November 1999 was predicted to produce observable flashes on the night side of the Moon. Here we report the unambiguous detection of five such impact flashes, three of which were seen simultaneously by other observers. We also observed a possible impact flash on 16 July 1999. All of the flashes were of very brief duration (<0.02 s), as expected for high-speed impacts.

  16. From H.G. Wells to Unmanned Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Boyd, John W.

    2005-01-01

    The possibility of planetary exploration has been a dream of the human race since Galileo discovered the moons of Jupiter in 1610. Visual sightings of bodies entering Earth s atmosphere have been made by Earth s inhabitants over the centuries. Over time, the many meteor showers (Leonid, Perseid) have provided dramatic evidence of the intense heat generated by a body entering Earth s atmosphere at hypervelocity speeds. More recently (in 1908), few viewed the Tunguska meteor that impacted in Siberia, but the destructive power on the countryside was awesome.

  17. STS-87 Payload Specialist Kadenyuk in white room

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine is assisted with final preparations before launch in the white room at Launch Pad 39B by Danny Wyatt, NASA quality assurance specialist, at left; Dave Law, USA mechanical technician, facing Kadenyuk; and Travis Thompson, USA orbiter vehicle closeout chief, at right. STS-87 is the fourth flight of the United States Microgravity Payload and Spartan-201. The 16- day mission will include the Collaborative Ukrainian Experiment (CUE), a collection of 10 plant space biology experiments that will fly in Columbias middeck and will feature an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings.

  18. Prospects for Ukrainian denuclearization after the Moscow trilateral statement

    SciTech Connect

    1994-03-01

    On January 14, at the Moscow summit, Presidents Bill Clinton, Boris Yeltsin of Russia and Leonid Kravchuk of Ukraine issued a trilateral statement that again commits Ukraine to denuclearize in compliance with START I and the Lisbon Protocol and to join the nuclear Non-Proliferation Treaty (NPT) as a non-nuclear-weapon state. Recognizing that scant media attention had been paid to the importance of the trilateral statement, the Arms Control Association (ACA) held a news conference on January 28 to provide background and context on the many issues that affect prospects for Ukrainian denuclearization.

  19. Possible Ursid Outburst on December 22, 2000

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Lyytinen, Esko; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The Ursid shower has broad Filament-type outbursts around the perihelion passage of parent 8P/Tuttle, but also isolated narrow outbursts at aphelion. We calculated Tuttle's dust trail encounters in the same way as for the Leonid showers. We discovered that it takes 6 centuries to change the orbit enough to bring the meteoroids to Earth's orbit. During that time, the meteoroids and comet separate in mean anomaly by 6 years, thus explaining the unusual aphelion occurrences. We predict enhanced activity on December 22, 2000, at around 7:29 LT.

  20. Hazards of Hypervelocity Impacts on Spacecraft

    DTIC Science & Technology

    2002-02-01

    Advances in Space Research , Vol. 20, No. 8, avoid impact penetration. 1997, pp. 1509-1512. 114 LAI, MURAD, AND McNEIL 8Foschini, L., and Cevolani, G...Results from the 1998 The FRECOPA Experiment," Advances in Space Research , Vol. 11, No. 12, Leonid Shower: I. Atmospheric Trajectories and Physical...Charging Effects," a 94 kms- 1 Microparticle Impact," Advances in Space Research , Vol. 17, NASA TP 2361, 1984. No. 12, 1996, pp. 87-91. 41Lal, S.

  1. The history of meteors and meteor showers

    NASA Astrophysics Data System (ADS)

    Hughes, David W.

    The history of meteors and meteor showers can effectively start with the work of Edmond Halley who overcome the Aristotelean view of meteors as being an upper atmospheric phenomenon and introduced their extraterrestrial nature. Halley also estimated their height and velocity. The observations of the Leonids in 1799, 1833 and 1866 established meteoroids as cometary debris. Two red herrings were caught — fixed radiants and hyperbolic velocities. But the 1890 to 1950 period with two-station meteor photography, meteor spectroscopy and the radar detection of meteors saw the subject well established.

  2. STS-87 Commander Kregel and his wife pose at LC 39B

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Commander Kevin Kregel poses with his wife, Jeannie Kregel, in front of Kennedy Space Center's Launch Pad 39B during final prelaunch activities leading up to the scheduled Nov. 19 liftoff. The other STS-87 crew members are Pilot Steven Lindsey; Mission Specialists Kalpana Chawla, Ph.D., Winston Scott, and Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite.

  3. Results of the IMO Video Meteor Network - January 2013

    NASA Astrophysics Data System (ADS)

    Molau, Sirko; Kac, Javor; Berko, Erno; Crivello, Stefano; Stomeo, Enrico; Igaz, Antal; Barentsen, Geert; Goncalves, Rui

    2013-04-01

    The January 2013 report of the IMO Video Meteor Network is presented, based on more than 13 000 meteors recorded by 71 cameras in nearly 5 000 hours of observing time. The flux density profile of the Quadrantids is presented which peaked on January 3. Shower parameters for December α-Draconids, January Leonids, Northern δ-Cancrids, ξ-Coronae Borealids, January ξ-Ursae Majorids, γ-Ursae Minorids, January Comae Berenicids, α-Coronae Borealids, and February ε-Virginids are presented. A possible new shower η-Corvids is announced, being active between January 20 and 26.

  4. The wave of the future - Searching for gravity waves

    NASA Astrophysics Data System (ADS)

    Goldsmith, Donald

    1991-04-01

    Research on gravity waves conducted by such scientists as Gamov, Wheeler, Weber and Zel'dovich is discussed. Particular attention is given to current trends in the theoretical analysis of gravity waves carried out by theorists Kip Thorne and Leonid Grishchuk. The problems discussed include the search for gravity waves; calculation of the types of gravity waves; the possibility of detecting gravity waves from localized sources, e.g., from the collision of two black holes in a distant galaxy or the collapse of a star, through the Laser Interferometer Gravitational Wave Observatory; and detection primordial gravity waves from the big bang.

  5. Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X)

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.

    2004-01-01

    We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

  6. Meteor-induced transient sporadic E as inferred from rapid-run ionosonde observations at midlatitudes

    NASA Astrophysics Data System (ADS)

    Maruyama, Takashi; Kato, Hisao; Nakamura, Maho

    2008-09-01

    Observations were made with a rapid-run ionosonde during a 1-month period from the end of July to the end of August 2002 that included the Perseid meteor shower. Ionograms were obtained at 1-minute intervals. All the echo traces below a virtual height of 200 km were hand-scaled for detecting weak and broken traces as well as well-determined sporadic E. Among the scaled E-region traces, a distinct meteor echo persisting for 40 min was observed. This long-duration meteor event was similar to that observed during the Leonid meteor shower in 2001. However the apparent height of the echo traces in the current event first decreased and then increased after equaling the height of a persistent sporadic E layer, while the apparent height of the long-duration meteor echo trace observed in Leonids 2001 remained nearly constant. The descending rate of the meteor echo was approximately 22 m/s, which was considerably greater than that of the tidal ion layer trapped in a downward-moving wind shear node. We ascribe the long-duration meteor echo to a transient and horizontally drifting sporadic E patch generated from meteor trail plasma.

  7. Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X).

    PubMed

    Jenniskens, Peter; Laux, Christophe O

    2004-01-01

    We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

  8. The mass and speed dependence of meteor air plasma temperatures.

    PubMed

    Jenniskens, Peter; Laux, Christophe O; Wilson, Michael A; Schaller, Emily L

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  9. Ukraine President Leonis Kuchma with P.S. Kadenyuk

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Kennedy Space Center, Fla. The president of the Ukraine, Leonid Kuchma, is flanked by Payload Specialist Leonid Kadenyuk, at left, and backup Payload Specialist Yaroslav Pustovyi, at right, both of the National Space Agency of Ukraine, during pre-launch activities leading up to the scheduled Nov. 19 launch of STS-87. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbias middeck and features an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk will be flying his first Shuttle mission on STS- 87.

  10. Influence of the meteoric stream on weather conditions: preliminary consideration

    NASA Astrophysics Data System (ADS)

    Granitskii, Lev V.; Borisevich, A. N.

    2000-12-01

    By the some estimation, about 150 tons of the meteoric matter are fall on the Earth every day. Some researchers note coincidence of the periods of activity of the most powerful meteoric stream with the periods of intensive falling of atmospheric precipitation. The unique meteoric stream Leonids represents the great interest as an example of possible correlation between meteors and power precipitation. The comet produced this stream is well known as Tempel-Tuttl comet, its orbital period is 33.3 years. With the same periodicity, the sharp strengthening of activity of a stream, which is called meteoric shower, is observed. Such meteoric stream during a night could cover the average monthly norm of fall of meteoric bodies at once in tens time. The analysis of meteorological data shows, that the winters of 1933, 1966, 1998 and 1999 years of a maximum Leonids activity are characterized by huge amount of snow. These anomalies have resulted in disasters in some of region. Under our suggestions, the anomaly rate of falling precipitation can be explained by the meteoric dust, which plays the role of the nucleuses of condensation. Thus, taking in to account the dada of regular meteoric stream, it's possible to make long term weather forecasting with the more preciseness.

  11. Ukraine President Leonis Kuchma with P.S. Kadenyuk

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Kennedy Space Center, Fla. The president of the Ukraine, Leonid Kuchma, is flanked by Payload Specialist Leonid Kadenyuk, at left, and backup Payload Specialist Yaroslav Pustovyi, at right, both of the National Space Agency of Ukraine, during pre-launch activities leading up to the scheduled Nov. 19 launch of STS-87. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbias middeck and features an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk will be flying his first Shuttle mission on STS- 87.

  12. Meteor44 Video Meteor Photometry

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.; Cooke, William J.

    2004-01-01

    Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The dynamic range of the (8bit) video data is extended by approximately 4 magnitudes for both meteors and stellar images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image's plate coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera s spectral response is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional visual magnitude units. Recent efforts include improved camera calibration procedures, long focal length 'streak' meteor photometry and two-station track determination. Meteor44 has been used to analyze data from the 2001, 2002 and 2003 MSFC Leonid observational campaigns as well as several lesser showers. The software is interactive and can be demonstrated using data from recent Leonid campaigns.

  13. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  14. Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X)

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.

    2004-01-01

    We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

  15. The Hubble Helix

    NASA Astrophysics Data System (ADS)

    McCullough, P. R.; Hubble Helix Team

    2002-12-01

    For the 14 hours of peak Leonid meteoroid flux in November 2002, the Hubble Space Telescope was pointed away from incoming meteoroids, and the solar arrays were oriented to minimize their cross-section. By coincidence, one of the most prominent planetary nebulae, the Helix Nebula, a.k.a. NGC 7293, was nearly opposite the incoming Leonids and could be observed. A ``Hubble Helix Team'' of volunteers led by M. Meixner (STScI) organized a nine-orbit campaign to observe the Helix with the ACS, WFPC2, NICMOS, and STIS. A contiguous 3 by 3 grid of 4kx4k-pixel ACS images covering much but not all of the Helix was exposed in two filters, Hα +[N II] (F658N) and [O III] (F502N). A few of the WFPC2 images observed in parallel also observed the nebula in [O I] (F631N) or He II 4686 (F469N) or Hα (F656N). NICMOS/NIC3 observations were obtained at two locations on the nebula and two off, in H2 (F212N) and Paschen-α (F187N). A few of the STIS parallel observations in [OII] (F28X0OII) were located on the nebula. The main purpose of this presentation is to advertise to all interested parties the availability of the non-proprietary data via the HST archive. Initial data analysis by the Hubble Helix Team will be presented in this poster.

  16. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  17. Meteor44 Video Meteor Photometry

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.; Cooke, William J.

    2004-01-01

    Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The dynamic range of the (8bit) video data is extended by approximately 4 magnitudes for both meteors and stellar images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image's plate coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera s spectral response is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional visual magnitude units. Recent efforts include improved camera calibration procedures, long focal length 'streak' meteor photometry and two-station track determination. Meteor44 has been used to analyze data from the 2001, 2002 and 2003 MSFC Leonid observational campaigns as well as several lesser showers. The software is interactive and can be demonstrated using data from recent Leonid campaigns.

  18. Meteor44 Video Meteor Photometry

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.; Cooke, William J.

    2004-01-01

    Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The dynamic range of the (8bit) video data is extended by approximately 4 magnitudes for both meteors and stellar images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image s plate coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera s spectral response is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional visual magnitude units. Recent efforts include improved camera calibration procedures, long focal length "streak" meteor photome&y and two-station track determination. Meteor44 has been used to analyze data from the 2001.2002 and 2003 MSFC Leonid observational campaigns as well as several lesser showers. The software is interactive and can be demonstrated using data from recent Leonid campaigns.

  19. Anomalous meteors from the observations with super-isocon TV systems

    NASA Astrophysics Data System (ADS)

    Kozak, P.; Watanabe, J.; Sato, M.

    2014-07-01

    There is a range of both optical and radar observations of meteors the behavior of which essentially differs from the behavior of most meteors. In some cases such meteors cannot be explained in the frame of the classic physical theory of meteors, in other cases the meteors are just of rare type. First of all these are the meteors with true hyperbolic velocities. In spite of the fact that most of hyperbolic orbits are the results of calculation errors, the meteors with extremely high velocities appreciably exceeding the hyperbolic limit of 73 km/s exist and can be of interstellar origin [1--3]. Another very rare phenomenon describes the possible cluster structure of meteor streams, which could be connected with the ejection of the substance from the cometary nucleus shortly before collision of the particles with the Earth [4]. Among anomalies connected with the meteor motion in the atmosphere one can note, first of all, the ultra-high altitudes of meteor beginnings exceeding 130--140 km [5--7]. Some other observations point to the beginning heights of bright meteors from Leonid shower on altitudes near 200 km [8]. The classic physical theory of meteors cannot explain their radiation on such high altitudes because of low air density [9]. Recently the results of TV observations of meteors with diffusive and cloudy structure appeared [9,10]. The results of observations in which, according to author's opinion, the meteors have a few kilometers transverse jets [9--11] were presented as well. There are video frames with bright meteor obtained with high temporal resolution, where authors declared the radiation, which could be an effect of a spread directly of the shock wave [12]. During many years' double-station observations of meteors which have been carrying out at Astronomical Observatory of Kyiv National Taras Shevchenko University the ultra-sensitive TV transmitting tubes of super-isocon type were used [7]. Given type of the tube is one of the most sensitive in the

  20. KSC-97PC1676

    NASA Image and Video Library

    1997-11-19

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine gives a ‘thumbs up’ in his launch and entry suit in the Operations and Checkout Building. He and the five other crew members of STS-87 will depart shortly for Launch Pad 39B, where the Space Shuttle Columbia awaits liftoff on a 16-day mission to perform microgravity and solar research. Kadenyuk will be flying his first mission on STS-87. During the mission, Kadenyuk will pollinate Brassica rapa plants as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia’s middeck and features an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings

  1. Abrupt climate change: Mechanisms, patterns, and impacts

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-08-01

    In the span of only a few decades, the global temperature can soar by more than a dozen degrees Celsius, a feat that 20 years ago was considered improbable, if not impossible. But recent research in the nascent field of rapid climate change has upended the dominant views of decades past. Focusing primarily on events during and after the most recent glaciation, from 80,000 years ago, the AGU monograph Abrupt Climate Change: Mechanisms, Patterns, and Impacts, edited by Harunur Rashid, Leonid Polyak, and Ellen Mosley-Thompson, explores the transient climate transitions that were only recently uncovered in climate proxies around the world. In this interview, Eos talks to Harunur Rashid about piecing together ancient climes, the effect of abrupt change on historical civilizations, and why younger researchers may be more worried about modern warming than their teachers.

  2. STS-87 Crew Breakfast

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The STS-87 flight crew enjoys the traditional pre-liftoff breakfast in the crew quarters of the Operations and Checkout Building. They are, from left, Mission Specialist Winston Scott; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; Commander Kevin Kregel; Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine; Mission Specialist Kalpana Chawla, Ph.D.; and Pilot Steven Lindsey. After a weather briefing, the flight crew will be fitted with their launch and entry suits and depart for Launch Pad 39B. Once there, they will take their positions in the crew cabin of the Space Shuttle Columbia to await liftoff during a two-and-a-half-hour window that will open at 2:46 p.m. EDT, Nov. 19.

  3. The STS-87 crew members and their spouses pose in front of Columbia at LC 39B

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crew of STS-87 pose with their spouses in front of Kennedy Space Center's Launch Pad 39B during final prelaunch activities leading up to the scheduled Nov. 19 liftoff. From left to right are: Vera Kadenyuk, wife of Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine who is next to Vera; Mission Specialist Winston Scott and his wife, Marilyn; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, and his wife, Hitomi; Jeannie Kregel, who is married to Commander Kevin Kregel standing next to her; Mission Specialist Kalpana Chawla, Ph.D., and her husband, Jean-Pierre Harrison; and Pilot Steven Lindsey and his wife Diane. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite.

  4. KSC-97PC1690

    NASA Image and Video Library

    1997-11-18

    The crew of STS-87 pose with their spouses in front of Kennedy Space Center’s Launch Pad 39B during final prelaunch activities leading up to the scheduled Nov. 19 liftoff. From left to right are: Vera Kadenyuk, wife of Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine who is next to Vera; Mission Specialist Winston Scott and his wife, Marilyn; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, and his wife, Hitomi; Jeannie Kregel, who is married to Commander Kevin Kregel standing next to her; Mission Specialist Kalpana Chawla, Ph.D., and her husband, Jean-Pierre Harrison; and Pilot Steven Lindsey and his wife Diane. STS-87 will be the fourth flight of the United States Microgravity Payload and the Spartan-201 deployable satellite

  5. Extraterrestrial meteors: a martian meteor and its parent comet.

    PubMed

    Selsis, Franck; Lemmon, Mark T; Vaubaillon, Jérémie; Bell, James F

    2005-06-02

    Regular meteor showers occur when a planet approaches the orbit of a periodic comet--for example, the Leonid shower is evident around 17 November every year as Earth skims past the dusty trail of comet Tempel-Tuttle. Such showers are expected to occur on Mars as well, and on 7 March last year, the panoramic camera of Spirit, the Mars Exploration Rover, revealed a curious streak across the martian sky. Here we show that the timing and orientation of this streak, and the shape of its light curve, are consistent with the existence of a regular meteor shower associated with the comet Wiseman-Skiff, which could be characterized as martian Cepheids.

  6. An Evaluation of the Accuracy of Meteor Shower Forecasts

    NASA Technical Reports Server (NTRS)

    Cooke, W.; Moser, D.

    2004-01-01

    Brought into being by the recent Leonid meteor storms, meteor shower forecasts are now regarded by many spacecraft projects as necessary inputs into the planning of spacecraft operations. We compare the shower forecasts made by various researchers over the past six years to actual shower observations in an attempt to create an overall picture of forecast accuracy, specifically focusing on the three aspects most important to space vehicles: 1) the time of shower maximum, 2) the half-width (duration), and 3) the maximum Zenith Hourly Rate (ZHR). It will be noted that, while the times of maxima are generally predicted to within several minutes, the peak ZHRs are often overestimated and shower half-widths are frequently not even calculated. The difficulties involved in converting shower ZHRs into the meteoroid fluxes needed to assess spacecraft risk are also discussed.

  7. The breast: from Ancient Greek myths to Hippocrates and Galen.

    PubMed

    Iavazzo, C R; Trompoukis, C; Siempos, I I; Falagas, M E

    2009-01-01

    This is a historical article about Ancient Greek literature from mythological times until the first centuries AD with regard to the female breast. We endeavoured to collect several elegant narratives on the topic as well as to explore the knowledge of Ancient Greek doctors on the role, physiology and pathology of breast and the treatment of its diseases. We identified such descriptions in myths regarding Amazons, Hercules, Zeus, Hera and Amaltheia. Furthermore, descriptions on the topic were also found in the work of Hippocrates, Aristoteles, Soranos, Alexander of Aphrodisias, Celsus, Archigenis, Leonides, Galen and Oribasius. We may conclude that some of today's medical knowledge or practice regarding the breast was also known in the historical period.

  8. ARACHNE: A neural-neuroglial network builder with remotely controlled parallel computing.

    PubMed

    Aleksin, Sergey G; Zheng, Kaiyu; Rusakov, Dmitri A; Savtchenko, Leonid P

    2017-03-31

    Creating and running realistic models of neural networks has hitherto been a task for computing professionals rather than experimental neuroscientists. This is mainly because such networks usually engage substantial computational resources, the handling of which requires specific programing skills. Here we put forward a newly developed simulation environment ARACHNE: it enables an investigator to build and explore cellular networks of arbitrary biophysical and architectural complexity using the logic of NEURON and a simple interface on a local computer or a mobile device. The interface can control, through the internet, an optimized computational kernel installed on a remote computer cluster. ARACHNE can combine neuronal (wired) and astroglial (extracellular volume-transmission driven) network types and adopt realistic cell models from the NEURON library. The program and documentation (current version) are available at GitHub repository https://github.com/LeonidSavtchenko/Arachne under the MIT License (MIT).

  9. STS-87 Payload Specialist Kadenyuk participates in the CEIT for his mission

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center is STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU). Here, Cosmonaut Kadenyuk is inspecting flowers for pollination and fertilization, which will occur as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission, scheduled to take off from KSC's Launch Pad 39-B on Nov. 19. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia's middeck and feature an educational component that involves evaluating the effects of microgravity on the pollinating Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk of the Ukraine will be flying his first Shuttle mission on STS-87.

  10. An Evaluation of the Accuracy of Meteor Shower Forecasts

    NASA Technical Reports Server (NTRS)

    Cooke, W.; Moser, D.

    2004-01-01

    Brought into being by the recent Leonid meteor storms, meteor shower forecasts are now regarded by many spacecraft projects as necessary inputs into the planning of spacecraft operations. We compare the shower forecasts made by various researchers over the past six years to actual shower observations in an attempt to create an overall picture of forecast accuracy, specifically focusing on the three aspects most important to space vehicles: 1) the time of shower maximum, 2) the half-width (duration), and 3) the maximum Zenith Hourly Rate (ZHR). It will be noted that, while the times of maxima are generally predicted to within several minutes, the peak ZHRs are often overestimated and shower half-widths are frequently not even calculated. The difficulties involved in converting shower ZHRs into the meteoroid fluxes needed to assess spacecraft risk are also discussed.

  11. KSC-97PC1704

    NASA Image and Video Library

    1997-11-19

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine is assisted with final preparations before launch in the white room at Launch Pad 39B by Danny Wyatt, NASA quality assurance specialist, at left; George Schram, USA mechanical technician, facing Kadenyuk; and Travis Thompson, USA orbiter vehicle closeout chief, at right. STS-87 is the fourth flight of the United States Microgravity Payload and Spartan-201. The 16-day mission will include the Collaborative Ukrainian Experiment (CUE), a collection of 10 plant space biology experiments that will fly in Columbia’s middeck and will feature an educational component that involves evaluating the effects of microgravity on Brassica rapa seedlings

  12. Systolic time intervals after a seven-day orbital flight

    NASA Astrophysics Data System (ADS)

    Groza, P.; Vrâncianu, R.; Lazǎr, M.; Baevski, R. M.; Funtova, V. L.

    Heart rate, systolic time intervals (pre-ejection period, left ventricular ejection time), ejection fraction, stroke volume and QT interval of two cosmonauts (Leonid Popov - L.P. and Dumitru Prunariu - D.P.) were studied before, during, and after an ergometric bicycle exercise test performed before and after the seven-day Soviet-Romanian orbital flight on the Soyuz 40 - Salyut 6 Complex in May 1981. For this purpose one precordial electrocardiogram (ecg) and the ear photodensitogram (den) were recorded stimulaneously. The method used permitted recording even during exercise, Ecg and den signals were stored on magnetic tape, processed in an analogue device and in a digital computer. The data obtained after landing suggest a slight cardiac deconditioning in L.P., demonstrated especially by augmentation of the pre-ejection period, which was unchanged in D.P. corresponding to a sympathoadrenergic hypertonia. The seven-day orbital flight has not produced important cardiovascular changes.

  13. KSC-97PC1516

    NASA Image and Video Library

    1997-10-02

    Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center is STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU). Here, Cosmonaut Kadenyuk is inspecting flowers for pollination and fertilization, which will occur as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission, scheduled to take off from KSC’s Launch Pad 39-B on Nov. 19. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia’s middeck and feature an educational component that involves evaluating the effects of microgravity on the pollinating Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk of the Ukraine will be flying his first Shuttle mission on STS-87

  14. KSC-97PC1517

    NASA Image and Video Library

    1997-10-02

    Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center is STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU). Here, Cosmonaut Kadenyuk is inspecting flowers for pollination and fertilization, which will occur as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission, scheduled to take off from KSC’s Launch Pad 39-B on Nov. 19. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia’s middeck and feature an educational component that involves evaluating the effects of microgravity on the pollinating Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk of the Ukraine will be flying his first Shuttle mission on STS-87

  15. STS-87 Payload Specialist Kadenyuk participates in the CEIT for his mission

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Participating in the Crew Equipment Integration Test (CEIT) at Kennedy Space Center is STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU). Here, Cosmonaut Kadenyuk is inspecting flowers for pollination and fertilization, which will occur as part of the Collaborative Ukrainian Experiment, or CUE, aboard Columbia during its 16-day mission, scheduled to take off from KSC's Launch Pad 39-B on Nov. 19. The CUE experiment is a collection of 10 plant space biology experiments that will fly in Columbia's middeck and feature an educational component that involves evaluating the effects of microgravity on the pollinating Brassica rapa seedlings. Students in Ukrainian and American schools will participate in the same experiment on the ground and have several live opportunities to discuss the experiment with Kadenyuk in Space. Kadenyuk of the Ukraine will be flying his first Shuttle mission on STS-87.

  16. Meteor storm evidence against the recent formation of lunar crater Giordano Bruno

    NASA Astrophysics Data System (ADS)

    Withers, Paul

    2001-04-01

    It has been suggested that the formation of the 22 km diameter lunar crater Giordano Bruno was witnessed in June 1178 A.D. To date, this hypothesis has not been well tested. Such an impact on the Earth would be "civilization threatening". Previous studies have shown that the formation of Giordano Bruno would lead to the arrival of 10 million tonnes of ejecta in the Earth's atmosphere in the following week. I calculate that this would cause a week-long meteor storm potentially comparable to the peak of the 1966 Leonids storm. The lack of any known historical records of such a storm is evidence against the recent formation of Giordano Bruno. Other tests of the hypothesis are also discussed, with emphasis on the lack of corroborating evidence for a very recent formation of the crater.

  17. Some problems of the theory of gravitation

    NASA Astrophysics Data System (ADS)

    Verozub, Leonid

    Leonid Verozub, lverozub@gmail.com Kharkov National University, Kharkov, Ukraine The contemporary observations pose serious challenges to the fundamental physics and astro-physics. We proceed from the equations of gravitation, based on an examination of foundations of the theory. (Ann. Phys. (Leipzig) 17, No. 1, 28 -51 (2008)). Namely, these equations are based on going back to Poincare's ideas about the relativity of geometry of space and time to the properties of measuring instruments, and on the consideration of the geodesic invariance as gauge invariance in the theory of gravitation. These equations do not contradict the observa-tional data, however, lead to two unexpected consequences, which allow you to test the theory: 1. They predict the existence of super-massive compact objects without event horizons, which are an alternative to black holes in the centers of galaxies. 2. They provide a simple and natural explanation for the accelerating expansion of the universe.

  18. A fireball analysis from Spanish meteor observations

    NASA Astrophysics Data System (ADS)

    Benítez Sánchez, O.; Ocaña González, F.

    2004-03-01

    Naked eye meteor records from Spain are used for an analysis of 3240 fireballs reported by members of the Sociedad de Observadores de Meteoros Y Cometas de España (SOMYCE) and by casual eye-witnesses from 1982 to 2000. This analysis concerns various areas, such as statistical studies of the colours and the frequency of fireballs in annual meteor showers. Annual and diurnal variations are also discussed. We describe the population index r for magnitudes brighter than m=-2 for ORI, VIR, AQU, TAU, CAP, QUA, GEM, LYR, LEO, KCG, PER and sporadic fireballs. The typical population index is always in the range ≃ 1.2 to 1.9, except for Perseids and Geminids. An investigation of visual fireballs radiants was attempted with the Radiant software. The sample of fireballs (282 fireballs with the path reported) only shows evidence for the Perseids and Leonids.

  19. An Alternative Explanation for a Screw-like Meteoric Train Photographed by Double-Station Observations

    NASA Astrophysics Data System (ADS)

    Wu, Guang-Jie

    2007-12-01

    Two-station observation of meteors, especially a meteor trains, provides an effective approach to the measurement of the physical parameters. We have collected four special groups of photographs of meteoric trains taken at two stations during Leonids 2001. One representative group has been measured and analyzed in detail. An analysis has been reported in our first paper. In this paper, an alternative explanation for the screw-like meteoric train is suggested based on some physical calculations. The results reveal that this train has a screw-like structure and, apparently, spoke beams. The mother meteor of this train may be negatively charged and moves forward along a left-hand screw trajectory under the effect of the geomagnetic field. The spoke beams might be the visual effect of the long time exposure of many particles released from the disintegrated meteoroid.

  20. KSC-97PC1750

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia makes a smooth touchdown on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5, completing the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  1. KSC-97PC1743

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia, with its drag chute deployed, touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  2. KSC-97PC1740

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  3. KSC-97PC1739

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  4. KSC-97PC1751

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia, with its drag chute deployed, touches down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  5. KSC-pa06l87

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia glides moments before its touchdown on Runway 33 at KSC’s Shuttle Landing Facility. Main gear touchdown occurred at 7:20:04 a.m. EST on Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  6. KSC-97PC1742

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  7. KSC-pa05l87

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia glides to its touchdown on Runway 33, the numbers visible below the orbiter, at KSC’s Shuttle Landing Facility. Main gear touchdown occurred at 7:20:04 a.m. EST on Dec. 5 to complete the 15-day, 16-hour and 34-minutelong STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  8. KSC-pa03l87

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  9. KSC-97PC1738

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia touches its main gear down on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5 to complete the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  10. KSC-97PC1749

    NASA Image and Video Library

    1997-12-05

    With Commander Kevin Kregel and Pilot Steven Lindsey at the controls, the orbiter Columbia makes a smooth touchdown on Runway 33 at KSC’s Shuttle Landing Facility at 7:20:04 a.m. EST Dec. 5, completing the 15-day, 16-hour and 34-minute-long STS-87 mission of 6.5 million miles. Also onboard the orbiter are Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of the National Space Development Agency of Japan; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  11. Near-Earth Object (NEO) Hazard Background

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.

    2005-01-01

    The fundamental problem regarding NEO hazards is that the Earth and other planets, as well as their moons, share the solar system with a vast number of small planetary bodies and orbiting debris. Objects of substantial size are typically classified as either comets or asteroids. Although the solar system is quite expansive, the planets and moons (as well as the Sun) are occasionally impacted by these objects. We live in a cosmic shooting gallery where collisions with Earth occur on a regular basis. Because the number of smaller comets and asteroids is believed to be much greater than larger objects, the frequency of impacts is significantly higher. Fortunately, the smaller objects, which are much more numerous, are usually neutralized by the Earth's protective atmosphere. It is estimated that between 1000 and 10,000 tons of debris fall to Earth each year, most of it in the form of dust particles and extremely small meteorites. With no atmosphere, the Moon's surface is continuously impacted with dust and small debris. On November 17 and 18, 1999, during the annual Leonid meteor shower, several lunar surface impacts were observed by amateur astronomers in North America. The Leonids result from the Earth's passage each year through the debris ejected from Comet Tempel-Tuttle. These annual showers provide a periodic reminder of the possibility of a much more consequential cosmic collision, and the heavily cratered lunar surface acts a constant testimony to the impact threat. The impact problem and those planetary bodies that are a threat have been discussed in great depth in a wide range of publications and books, such as The Spaceguard Survey , Hazards Due to Comets and Asteroids, and Cosmic Catastrophes. This paper gives a brief overview on the background of this problem and address some limitations of ground-based surveys for detection of small and/or faint near-Earth objects.

  12. Meteors do not break exogenous organic molecules into high yields of diatomics

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Schaller, Emily L.; Laux, Christophe O.; Wilson, Michael A.; Schmidt, Greg; Rairden, Rick L.

    2004-01-01

    Meteoroids that dominate the Earth's extraterrestrial mass influx (50-300 microm size range) may have contributed a unique blend of exogenous organic molecules at the time of the origin of life. Such meteoroids are so large that most of their mass is ablated in the Earth's atmosphere. In the process, organic molecules are decomposed and chemically altered to molecules differently from those delivered to the Earth's surface by smaller (<50 microm) micrometeorites and larger (>10 cm) meteorites. The question addressed here is whether the organic matter in these meteoroids is fully decomposed into atoms or diatomic compounds during ablation. If not, then the ablation products made available for prebiotic organic chemistry, and perhaps early biology, might have retained some memory of their astrophysical nature. To test this hypothesis we searched for CN emission in meteor spectra in an airborne experiment during the 2001 Leonid meteor storm. We found that the meteor's light-emitting air plasma, which included products of meteor ablation, contained less than 1 CN molecule for every 30 meteoric iron atoms. This contrasts sharply with the nitrogen/iron ratio of 1:1.2 in the solid matter of comet 1P/Halley. Unless the nitrogen content or the abundance of complex organic matter in the Leonid parent body, comet 55P/Tempel-Tuttle, differs from that in comet 1P/Halley, it appears that very little of that organic nitrogen decomposes into CN molecules during meteor ablation in the rarefied flow conditions that characterize the atmospheric entry of meteoroids approximately 50 microm-10 cm in size. We propose that the organics of such meteoroids survive instead as larger compounds.

  13. Studies of Transient Meteor Activity

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter M. M.

    2002-01-01

    Meteoroids bombard Earth's atmosphere daily, but occasionally meteor rates increase to unusual high levels when Earth crosses the relatively fresh ejecta of comets. These transient events in meteor activity provide clues about the whereabouts of Earth-threatening long-period comets, the mechanisms of large-grain dust ejection from comets, and the particle composition and size distribution of the cometary ejecta. Observations of these transient events provide important insight in natural processes that determine the large grain dust environment of comets, in natural phenomena that were prevalent during the time of the origin of life, and in processes that determine the hazard of civilizations to large impacts and of man-made satellites to the periodic blizzard of small meteoroids. In this proposal, three tasks form a coherent program aimed at elucidating various aspects of meteor outbursts, with special reference to planetary astronomy and astrobiology. Task 1 was a ground-based effort to observe periods of transient meteor activity. This includes: (1) stereoscopic imaging of meteors during transient meteor events for measurements of particle size distribution, meteoroid orbital dispersions and fluxes; and (2) technical support for Global-MS-Net, a network of amateur-operated automatic counting stations for meteor reflections from commercial VHF radio and TV broadcasting stations, keeping a 24h vigil on the level of meteor activity for the detection of new meteor streams. Task 2 consisted of ground-based and satellite born spectroscopic observations of meteors and meteor trains during transient meteor events for measurements of elemental composition, the presence of organic matter in the meteoroids, and products generated by the interaction of the meteoroid with the atmosphere. Task 3 was an airborne effort to explore the 2000 Leonid meteor outbursts, which are anticipated to be the most significant of transient meteor activity events in the remainder of the

  14. Meteors do not break exogenous organic molecules into high yields of diatomics.

    PubMed

    Jenniskens, Peter; Schaller, Emily L; Laux, Christophe O; Wilson, Michael A; Schmidt, Greg; Rairden, Rick L

    2004-01-01

    Meteoroids that dominate the Earth's extraterrestrial mass influx (50-300 microm size range) may have contributed a unique blend of exogenous organic molecules at the time of the origin of life. Such meteoroids are so large that most of their mass is ablated in the Earth's atmosphere. In the process, organic molecules are decomposed and chemically altered to molecules differently from those delivered to the Earth's surface by smaller (<50 microm) micrometeorites and larger (>10 cm) meteorites. The question addressed here is whether the organic matter in these meteoroids is fully decomposed into atoms or diatomic compounds during ablation. If not, then the ablation products made available for prebiotic organic chemistry, and perhaps early biology, might have retained some memory of their astrophysical nature. To test this hypothesis we searched for CN emission in meteor spectra in an airborne experiment during the 2001 Leonid meteor storm. We found that the meteor's light-emitting air plasma, which included products of meteor ablation, contained less than 1 CN molecule for every 30 meteoric iron atoms. This contrasts sharply with the nitrogen/iron ratio of 1:1.2 in the solid matter of comet 1P/Halley. Unless the nitrogen content or the abundance of complex organic matter in the Leonid parent body, comet 55P/Tempel-Tuttle, differs from that in comet 1P/Halley, it appears that very little of that organic nitrogen decomposes into CN molecules during meteor ablation in the rarefied flow conditions that characterize the atmospheric entry of meteoroids approximately 50 microm-10 cm in size. We propose that the organics of such meteoroids survive instead as larger compounds.

  15. Lunar Sodium Data and Constraints on Source Processes

    NASA Astrophysics Data System (ADS)

    Naidu, Shantanu; Killen, R. M.; Sarantos, M.; Potter, A. E.; Sharma, A. S.

    2008-09-01

    One of the controversies concerning the origin of surface-bounded exospheres is whether sputtering is a viable source of exospheric particles, and in particular whether sputtering by highly charged ions is an extremely effective process. Another process that has been suggested by Sarantos et al (2008) is that ion-induced defects can enhance photon-stimulated desorption. The Moon offers a unique laboratory in which these processes can be studied. We have ancillary data about the Moon, including data on composition of the surface and on the flux of electrons to the surface. The Earth's Moon is unique in that it traverses the Earth's magnetosphere, where it is shielded from the solar wind. At times in its orbit the Moon traverses through the Earth's plasma sheet, while at other times it is not exposed to plasma sheet ions in its path through the magnetosphere. Lunar Prospector orbited the Moon for 18 months beginning in January, 1998. We have ground-based observations of the sodium exosphere during this time period, only some of which were published (Potter et al., 2000). We have reduced additional data obtained at the McMath-Pierce solar telescope during the decade preceding Lunar Prospector and during the mission. The observations coincide with two Magnetic Cloud events, one interplanetary shock event, two nominal solar wind times, and one intense meteor shower event, that of the Leonids 1998. By modeling the atmosphere using in-situ observations from Lunar Prospector, and ancillary data from ACE, we will constrain the importance of sputtering and photon-stimulated desorption. By comparing the exosphere during the Leonid shower event with that nominal inside the magnetosphere, we can constrain the importance of micrometeoritic vaporization, a continuous source caused by extremely small dust grains. We acknowledge support of this work by the NASA Planetary Astronomy and LASER programs.

  16. Meteors do not break exogenous organic molecules into high yields of diatomics

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Schaller, Emily L.; Laux, Christophe O.; Wilson, Michael A.; Schmidt, Greg; Rairden, Rick L.

    2004-01-01

    Meteoroids that dominate the Earth's extraterrestrial mass influx (50-300 microm size range) may have contributed a unique blend of exogenous organic molecules at the time of the origin of life. Such meteoroids are so large that most of their mass is ablated in the Earth's atmosphere. In the process, organic molecules are decomposed and chemically altered to molecules differently from those delivered to the Earth's surface by smaller (<50 microm) micrometeorites and larger (>10 cm) meteorites. The question addressed here is whether the organic matter in these meteoroids is fully decomposed into atoms or diatomic compounds during ablation. If not, then the ablation products made available for prebiotic organic chemistry, and perhaps early biology, might have retained some memory of their astrophysical nature. To test this hypothesis we searched for CN emission in meteor spectra in an airborne experiment during the 2001 Leonid meteor storm. We found that the meteor's light-emitting air plasma, which included products of meteor ablation, contained less than 1 CN molecule for every 30 meteoric iron atoms. This contrasts sharply with the nitrogen/iron ratio of 1:1.2 in the solid matter of comet 1P/Halley. Unless the nitrogen content or the abundance of complex organic matter in the Leonid parent body, comet 55P/Tempel-Tuttle, differs from that in comet 1P/Halley, it appears that very little of that organic nitrogen decomposes into CN molecules during meteor ablation in the rarefied flow conditions that characterize the atmospheric entry of meteoroids approximately 50 microm-10 cm in size. We propose that the organics of such meteoroids survive instead as larger compounds.

  17. Determination of meteoroid fluxes by using a high-res all-sky camera

    NASA Astrophysics Data System (ADS)

    Trigo-Rodriguez, J. M.; Castro-Tirado, A. J.; Gural, P. S.; Jelinek, M.; Vitek, S.; Llorca, J.; Fabregat, J.; Troughton, B.; Galvez, F.

    For several decades there was a large gap between the typical masses of the meteoroids detectable by ground-based photographic camera networks that typically reach -4 magnitude (Spurný and Boroviˇ ka, 2002) and those observed visually (mag. +6). Consequently, visual observations and medium-field photographic exposures have played an important role in determining meteoric fluxes during periods of moderate or high meteoric activity (Jenniskens, 1994, 1995; Trigo-Rodríguez et al., 2001, 2004a). However, the gap for recorded meteors from all-sky systems can be narrowed by using charge coupled devices (CCD) cameras to the detection of meteors until +2/+3 magnitude as was pointed out recently (Trigo-Rodríguez et al. 2004b). A full description of the system and its application to different research fields appears in Castro-Tirado et al. (2005). Continuous meteor and fireball observations have been carried out by the SPanish Meteor Network (SPMN) all sky cameras located in Barcelona, Huelva and Malaga provinces (Spain) during 2005-2006. As a result of the continuous monitoring of the night sky bright bolides have been recorded, but also tens of meteors from different streams or sporadics. On the basis of counting the recorded meteors emanating from different meteor streams in the all-sky exposures, we are able to estimate the meteoroid fluxes for different streams. Determination of these fluxes was made by using a meteor simulation tool (MeteorSim) in order to convert the count rates obtained from the all-sky camera observations to meteoroid spatial number densities. The tool employed was a Monte Carlo based simulation first detailed in an International Meteor Conference proceeding paper by Gural (2002). The same tool had been applied in Gural and Jenniskens (2000) to estimate both the mass ratio and flux for the Leonids, as well as in Molau, Gural, and Okamura (2002) to correct for variable detection efficiencies between multiple sensors and changing radiant

  18. Obituary: Kenneth L. Franklin, 1923-2007

    NASA Astrophysics Data System (ADS)

    Rao, Joe; Degrasse Tyson, Neil

    2007-12-01

    Renowned astronomer and astronomy popularizer Kenneth L. Franklin died early Monday morning, June 18, 2007, in Boulder, Colorado, two weeks after undergoing heart surgery. He was 84 years old. Kenneth Linn Franklin, the only child of Myles and Ruth (Houston) Franklin, was born March 25, 1923 in Alemeda, California. Ken obtained his Ph.D. in astronomy in 1953 at the University of California, Berkeley. From 1954 to 1956 he was a research fellow in radio astronomy at the Department of Terrestrial Magnetism, Carnegie Institution of Washington, DC. While there, he and Bernard F. Burke discovered radio emissions from the planet Jupiter. They announced their find on April 6, 1955, at a meeting of the American Astronomical Society (AAS). In 1956 Ken joined the staff of the American Museum-Hayden Planetarium, where he later served as chairman and chief scientist. Over the course of thirty years he wrote and/or presented innumerable sky shows for the planetarium sky theater, taught popular and technical courses in astronomy, and answered questions from the public. Ken was frequently consulted by local industries engaged in the space program, as well as by the news media and publishers. He was often interviewed on local and national radio and television, especially when a celestial event of special interest was due to occur. On the first page of the November 1966 issue of Sky & Telescope, in comments about the upcoming Leonid meteor shower, Franklin stuck his neck out. Based on some calculations that he'd made, he said he felt we were going to be in for a "interesting display." His was one of the few forecasts that suggested the '66 Leonids might be memorable. As it turned out, he was right — that year observers experienced the now-legendary Leonid meteor storm. From 1973 to 1979, Ken was the AAS's public-affairs officer. For two decades he also served in the society's Harlow Shapley Visiting Lecturer Program, speaking at one or two colleges each year. Ken was an active

  19. The 2011 Draconid Shower Risk to Earth-Orbiting Satellites

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; Moser, Danielle E.

    2010-01-01

    Current meteor shower forecast models project a strong Draconid outburst, possibly a storm, on October 8, 2011, with a duration of approximately 7 hours and peaking between 19 and 21 hours UT. Predicted rates span an order of magnitude, with maximum Zenithal Hourly Rates (ZHRs) ranging from a few tens to several hundred. Calibration of the NASA MSFC Meteoroid Stream Model 1 to radar and optical observations of past apparitions, particularly the 2005 Draconid outburst 2, suggest that the maximum rate will be several hundreds per hour. Given the high spatial density of the Draconid stream, this implies a maximum meteoroid flux of 5-10 Draconids km(exp -2)/hr (to a limiting diameter of 1 mm), some 25-50 times greater than the normal sporadic flux of 0.2 km(exp -2)/ hr for particles of this size. Total outburst fluence, assuming a maximum ZHR of 750, is 15.5 Draconids km(exp -2), resulting in an overall 10x risk increase to spacecraft surfaces vulnerable to hypervelocity impacts by 1 mm particles. It is now established that a significant fraction of spacecraft anomalies produced by shower meteoroids (e.g. OLYMPUS and LandSat 5) are caused by electrostatic discharges produced by meteoroid impacts. In these cases, the charge generated is roughly proportional to v(exp 3.5(4)), giving a Draconid moving at 20 km/s approximately 1/80th the electrical damage potential of a Leonid of the same mass. In other words, a Draconid outburst with a maximum ZHR of 800 presents the same electrical risk as a normal Leonid shower with a ZHR of 15, assuming the mass indices and shower durations are the same. This is supported by the fact that no spacecraft electrical anomalies were reported during the strong Draconid outbursts of 1985 and 1998. However, the lack of past anomalies should not be taken as carte blanche for satellite operators to ignore the 2011 Draconids, as the upcoming outburst will constitute a period of enhanced risk for vehicles in near-Earth space. Each spacecrft is

  20. Mathematical modeling of tumor therapy with oncolytic viruses: effects of parametric heterogeneity on cell dynamics

    PubMed Central

    Karev, Georgy P; Novozhilov, Artem S; Koonin, Eugene V

    2006-01-01

    Background: One of the mechanisms that ensure cancer robustness is tumor heterogeneity, and its effects on tumor cells dynamics have to be taken into account when studying cancer progression. There is no unifying theoretical framework in mathematical modeling of carcinogenesis that would account for parametric heterogeneity. Results: Here we formulate a modeling approach that naturally takes stock of inherent cancer cell heterogeneity and illustrate it with a model of interaction between a tumor and an oncolytic virus. We show that several phenomena that are absent in homogeneous models, such as cancer recurrence, tumor dormancy, and others, appear in heterogeneous setting. We also demonstrate that, within the applied modeling framework, to overcome the adverse effect of tumor cell heterogeneity on the outcome of cancer treatment, a heterogeneous population of an oncolytic virus must be used. Heterogeneity in parameters of the model, such as tumor cell susceptibility to virus infection and the ability of an oncolytic virus to infect tumor cells, can lead to complex, irregular evolution of the tumor. Thus, quasi-chaotic behavior of the tumor-virus system can be caused not only by random perturbations but also by the heterogeneity of the tumor and the virus. Conclusion: The modeling approach described here reveals the importance of tumor cell and virus heterogeneity for the outcome of cancer therapy. It should be straightforward to apply these techniques to mathematical modeling of other types of anticancer therapy. Reviewers: Leonid Hanin (nominated by Arcady Mushegian), Natalia Komarova (nominated by Orly Alter), and David Krakauer. PMID:17018145

  1. American Zodiac: Astronomical signs in Dickinson, Melville, and Poe

    NASA Astrophysics Data System (ADS)

    Ricca, Bradley James

    2003-11-01

    Science and literature, two means of inquiry now thought in opposition (if not posed as outright contradiction) emerged for a moment in the nineteenth century as provocatively complimentary in their methods of reading. In America, astronomy in particular provided a rich, complex subject for writers of the imagination to think about in terms of content and methodology. The purpose of my study is to uncover these unacknowledged astronomical referents in the works of Emily Dickinson, Herman Melville, and Edgar Allan Poe, and engage them as interpretive contexts in new readings of their most esoteric projects; specifically, Dickinson's solstice and circumference poetry, the Plinlimmon pamphlet in Melville's Pierre, and Poe's Eureka. After providing historical context through the shared public experience of the 1833 Leonid Meteor Storm, I uncover several astronomical and scientific sources for these writers: Denison Olmsted for Dickinson; Gauss and Plotinus for Melville; and Kepler and Alexander von Humboldt for Poe, among others. Exploring these sources in close readings of their works, I find that these authors employ astronomical facts in very different, metaphorical ways in response to the larger challenge of navigating their own poetics between the emerging new laws of science and the immeasurability of human feeling evoked by the unknown Universe.

  2. The activity of autumn meteor showers in 2006-2008

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna

    2015-03-01

    The purpose of meteor observations in INASAN is the study of meteor showers, as the elements of the migrant substance of the Solar System, and estimation of risk of hazardous collisions of spacecrafts with the particles of streams. Therefore we need to analyze the meteor events with brightness of up to 8 m, which stay in meteoroid streams for a long time and can be a hazardous for the spacecraft. The results of our single station TV observations of autumn meteor showers for the period from 2006 to 2008 are presented. The high-sensitive hybrid camera (the system with coupled of the Image Intensifier) FAVOR with limiting magnitude for meteors about 9m. . .10m in the field of view 20 × 18 was used for observations. In 2006-2008 from October to November more than 3 thousand of meteors were detected, 65% from them have the brightness from 6m to 9m. The identification with autumn meteor showers (Orionids, Taurids, Draconids, Leonids) was carried out. In order to estimate the density of the influx of meteor matter to the Earth for these meteor showers the Index of meteor activity (IMA) was calculated. The IMA distribution for the period 2006 - 2008 is given. The distributions of autumn meteor showers (the meteors with brightness of up to 8 m) by stellar magnitude from 2006 to 2008 are also presented.

  3. Physics at the Moscow State University in 70-th. Photographs

    NASA Astrophysics Data System (ADS)

    Gaina, Alex B.

    The Internet proceeding contains various photographs and autographs of scientists from the Moscow State University, made during 70-th and 80-th years of XX-th Century. While no the album refers to Physics in totality, the main part of the album does refer. It includes photographs and autographs of the Members of the Academy of Sciences of U.S.S.R. Il'ya M. Lifshitz, Alexander I. Ishlinskii, Leonid V. Keldysh, Nobel Prize Winners Vitaly L. Ginzburg and Andrej D. Sakharov, Professors: I.M. Ternov, M.I. Kaganov, V.I. Grigor'ev, V.R. Khalilov, V.Ch. Zhukovskij, V.G. Bagrov (Tomsk State University) and other. Another part of peoples on the photographs became later University professors and Members of Academies. A photo concerns the graduated from the Moscow University, astronomer Vladimir A. Albitzky (1892-1952) made in Odessa during the First World War, while another concerns the School "Quantum Particles in intense fields" held in Chisinau in May 1985.

  4. STS-87 crew in front of LC-39B during TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from Pad 39B at Kennedy Space Center (KSC), poses at the pad during a break in the Terminal Countdown Demonstration Test (TCDT) at KSC. Standing in front of the Shuttle Columbia are, from left, Commander Kevin Kregel; Mission Specialist Kalpana Chawla, Ph.D.; Pilot Steven Lindsey; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; Backup Payload Specialist Yaroslav Pustovyi, Ph.D., of the National Space Agency of Ukraine (NSAU); Payload Specialist Leonid Kadenyuk of NSAU; and Mission Specialist Winston Scott. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

  5. The Lunar Atmosphere as a Cosmic-Ray Detector

    NASA Technical Reports Server (NTRS)

    Wilson, T. L.

    2007-01-01

    The recent discovery of a tenuous sodium (Na) atmosphere on the Moon and Mercury has renewed interest in studying the lunar atmosphere since the physics involved for the two bodies is thought to be of similar nature. Na came as a surprise because it had been missed by in situ UV measurements made during the Apollo program. The new lunar observations involve the visible D1 (5896 ) and D2 (5890 ) wavelengths which are highly efficient at scattering sunlight. Although its lunar source and morphology is still not completely understood, Na is present as a collisionless exosphere - apparently in the form of a cometary-type coma with a tail that can extend hundreds of lunar radii during Leonid showers. The global shape of the atmosphere, in particular for the shaded antisolar side, has been modelled by Smyth. Since planetary atmospheres can be used as cosmic-ray (CR) spectrometers by means of their fluorescence excited by CR-induced air shower particles, the subject of the Moon s atmosphere as a CR detector will be discussed here.

  6. Hazards by meteoroid Impacts onto operational spacecraft

    NASA Astrophysics Data System (ADS)

    Landgraf, M.; Jehn, R.; Flury, W.

    Operational spacecraft in Earth orbit or on interplanetary trajectories are exposed to high-velocity particles that can cause damage to sensitive on-board instrumentation. In general there are two types of hazard: direct destruction of functional elements by impacts, and indirect disturbance of instruments by the generated impact plasma. The latter poses a threat especially for high-voltage instrumentation and electronics. While most meteoroids have sizes in the order of a few micrometre, and typical masses of 10-15 kg, the most dangerous population with sizes in the millimetre and masses in the milligramme range exhibits still substantial impact fluxes in the order of 2 × 10-11 m-2 s-1 . This level of activity can by significantly elevated during passages of the spacecraft through cometary trails, which on Earth cause events like the well-known Leonid and Perseid meteor streams. The total mass flux of micrometeoroids onto Earth is about 107 kg yr-1 , which is about one order of magnitude less than the estimated mass flux of large objects like comets and asteroids with individual masses above 105 kg. In order to protect spacecraft from the advert effects of meteoroid impacts, ESA performs safety operations on its spacecraft during meteor streams, supported by real-time measurements of the meteor activity. A summary of past and future activities is given.

  7. Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; Koehler, H. M.

    2011-01-01

    Since early 2006, NASA s Marshall Space Flight Center has been routinely monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 12 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. (2000a, b) for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-800 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated from the observed flash intensity.

  8. Studies on different geophysical and extra-terrestrial events within the Earth-ionosphere cavity in terms of ULF/ELF/VLF radio waves

    NASA Astrophysics Data System (ADS)

    Sanfui, Minu; Haldar, D. K.; Biswas, Debasish

    2016-10-01

    The space between the two spherical conducting shells, Earth surface and the lower boundary of the ionosphere, behaves as a spherical cavity in which some electromagnetic signals can propagate a long distance and is called Earth-ionosphere waveguide. Through this waveguide ultra low frequency (ULF), extremely low frequency (ELF) and very low frequency (VLF) signals can propagate efficiently with low attenuation. Resonances which occur for ELF waves due to round-the-world propagation interfering with 2n π phase difference are called Schumann resonances. Lightnings are the main sources of energy continuously producing these electromagnetic radiations from the troposphere. Some fixed frequency signals are also transmitted through the waveguide from different stations for navigation purposes. The intensity and phase of these signals at a particular position depend on the waveguide characteristics which are highly influenced by different natural events. Thus the signatures of different geophysical and extra-terrestrial events may be investigated by studying these signals through proper monitoring of the time series data using suitable techniques. In this article, we provide a review on ULF, ELF and VLF signals within the waveguide in terms of different geophysical and extra-terrestrial events like lightning, earthquakes, Leonid meteor shower, solar flares, solar eclipse, geomagnetic storms, and TLEs etc.

  9. A synthetical index of the potential threats about intense activities of meteors

    NASA Astrophysics Data System (ADS)

    Wu, Guang-jie

    2006-10-01

    In the present age, several techniques for the application to the observation of meteors and meteor showers have been developed in modern meteor astronomy. The initial definition for a meteor storm based on the visual observation with a Zenithal Hourly Rate of above 1000 seems insufficient now, since it only means a storm or burst of meteors in numbers and means that an eyewitness could have a chance to see a spectacular meteor show. Up to now, peoples have also recorded the meteoric flashes on the Moon during the Leonid meteor showers. Especially, the increasing activities of mankind in space for scientific, commercial and military purposes, have led to an increase in the problems concerning the safety of the satellites, space stations and astronauts. How the intense activity of a meteor storm is defined and forecast, some new points of view are needed. In this paper, several aspects about the intensity of the meteor storm are analyzed, including the number, mass, impulse, energy, electric charge, different purposes and different physical meanings. Finally, a synthetical index denoting the activity and potential threat of an intense meteor shower is suggested.

  10. STS-87 crew walkout for TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participated in the Terminal Countdown Demonstration Test (TCDT) at KSC. Simulating the walk-out from the Operations and Checkout Building before entering a van to take them to the launch pad are Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (at back left); Pilot Steve Lindsey (back right); Mission Specialist Kalpana Chawla, Ph.D. (middle left); Mission Specialist Winston Scott (middle right); Takao Doi, Ph.D., of the National Space Development Agency of Japan (front left); and Commander Kevin Kregel. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

  11. Modulational excitation of low-frequency dust acoustic waves in the Earth's lower ionosphere

    SciTech Connect

    Kopnin, S. I.; Popel, S. I.; Yu, M. Y.

    2007-04-15

    During the observation of Perseid, Leonid, Gemenid, and Orionid meteor showers, stable low-frequency lines in the frequency range of 20-60 Hz were recorded against the radio-frequency noise background. A physical mechanism for this effect is proposed, and it is established that the effect itself is related to the modulational interaction between electromagnetic and dust acoustic waves. The dynamics of the components of a complex (dusty) ionospheric plasma with dust produced from the evolution of meteoric material is described. The conditions for the existence of dust acoustic waves in the ionosphere are considered, and the waves are shown to dissipate energy mainly in collisions of neutral particles with charged dust grains. The modulational instability of electromagnetic waves in a complex (dusty) ionospheric plasma is analyzed and is found to be driven by the nonlinear Joule heating, the ponderomotive force, and the processes governing dust charging and dynamics. The conditions for the onset of the modulational instability of electromagnetic waves, as well as its growth rate and threshold, are determined for both daytime and nighttime. It is shown that low-frequency perturbations generated in the modulational interaction are related to dust acoustic waves.

  12. On the ejection and dispersion velocities of meteor particles

    NASA Astrophysics Data System (ADS)

    Kresak, L.

    1992-07-01

    This paper is a reaction to the attempts to determine the ejection velocities of meteor particles from cometary nuclei using the statistics of photographic meteor orbits. It is argued that this is essentially impossible. The original dispersion velocities are masked completely by much larger measuring errors, and for all permanent meteor showers also by the accumulated effects of planetary perturbations. The perturbations, appearing after sufficient spread particles along the orbit, are on the average about 25-times more effective in the direction perpendicular to the orbital plane than in the direction of motion, and they are about 50-times more effective for typical comets of Jupiter family than for those of Halley type. The latter disproportion is responsible for the widely different distribution of the revolution periods of comets, annual meteor showers, and temporary meteor storms. In addition to direct spacecraft measurements, the only feasible sources of information on the ejection velocities are meteor storms, like the Draconids or Leonids, appearing only several times per century, and the cometary dust trail discovered by IRAS. Both of them indicate incomparably lower velocities than the meteor data - only a few meters per second - and a substantial role of the solar radiation pressure in the initial dispersion.

  13. Remembering AB

    NASA Astrophysics Data System (ADS)

    Belyayev, S. T.

    2013-06-01

    In 1947 I became a second-year student at Moscow State University's Physics and Engineering Department, where a part of the week's classes were taught at base organizations. Our group's base was the future Kurchatov Institute, at that time known as the mysterious "Laboratory N^circ 2," and later as LIPAN. . Besides group lectures and practical work at the experimental laboratories, we also had access to the general seminars which Igor Vasilyevich Kurchatov tried to hold, with Leonid Vasilyevich Groshev filling in when he was absent. At the seminar, theorists spoke as welcome co-presenters and commentators. In 1949 I felt ready to approach A. B. Migdal to ask if I could transfer to his theoretical sector. In response, he suggested a number of simple qualitative problems, which I then successfully solved. (Incidentally, AB used the very same "introductory problems" for screening many generations of students.) So I wound up among AB's students. From 1952 on (for 10 years) I also served as an employee of the Migdal Sector. My memoirs here are mainly inspired by these years of constant communication with AB. After my departure for Novosibirsk in 1962, although our meetings still took place, they became occasional....

  14. NASDA President Isao Uchida shakes hands with STS-87 Mission Specialist Takao Doi, Ph.D., after land

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, shakes hands with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  15. NASDA President Isao Uchida greets STS-87 Mission Specialist Takao Doi, Ph.D., after landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, chats with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34- minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  16. Comet outbursts and the meteor showers

    NASA Astrophysics Data System (ADS)

    Guliyev, A. S.; Kokhirova, G. I.; Poladova, U. D.

    2014-07-01

    The features of 116 comets that have shown an outbursts in their brightness, are considered in the paper. The hypothesis on that the outburst in activity of comets are caused by their passing through meteoroid streams is studied. For this purpose the orbital elements of such comets relative to the planes of motion of 68 meteor showers from Cook's catalogue are analyzed. It was found that four of the nearest and distant nodes of comet orbits relative to the planes of motion of nine meteor showers exceeds the average statistical background with confidence probability from 0.90 to 0.95, and more than 0.95, respectively. The October Draconids, Aurigids, kappa-Serpentids, delta-Draconids, sigma-Hydrids}, Coma Berenicids, Leonids, Leo Minorids, and Perseids showers are the most effective. The results of calculation show that often, the comets outbursts may be caused by collisions of comets with meteoroids under the passing through the meteoroid streams that are producing listed meteor showers as well as solar activity.

  17. Optical Pattern Recognition

    NASA Astrophysics Data System (ADS)

    Yu, Francis T. S.; Jutamulia, Suganda

    2008-10-01

    Contributors; Preface; 1. Pattern recognition with optics Francis T. S. Yu and Don A. Gregory; 2. Hybrid neural networks for nonlinear pattern recognition Taiwei Lu; 3. Wavelets, optics, and pattern recognition Yao Li and Yunglong Sheng; 4. Applications of the fractional Fourier transform to optical pattern recognition David Mendlovic, Zeev Zalesky and Haldum M. Oxaktas; 5. Optical implementation of mathematical morphology Tien-Hsin Chao; 6. Nonlinear optical correlators with improved discrimination capability for object location and recognition Leonid P. Yaroslavsky; 7. Distortion-invariant quadratic filters Gregory Gheen; 8. Composite filter synthesis as applied to pattern recognition Shizhou Yin and Guowen Lu; 9. Iterative procedures in electro-optical pattern recognition Joseph Shamir; 10. Optoelectronic hybrid system for three-dimensional object pattern recognition Guoguang Mu, Mingzhe Lu and Ying Sun; 11. Applications of photrefractive devices in optical pattern recognition Ziangyang Yang; 12. Optical pattern recognition with microlasers Eung-Gi Paek; 13. Optical properties and applications of bacteriorhodopsin Q. Wang Song and Yu-He Zhang; 14. Liquid-crystal spatial light modulators Aris Tanone and Suganda Jutamulia; 15. Representations of fully complex functions on real-time spatial light modulators Robert W. Cohn and Laurence G. Hassbrook; Index.

  18. SPA Meteor Section Results: 2006

    NASA Astrophysics Data System (ADS)

    McBeath, Alastair

    2010-12-01

    A summary of the main analyzed results and other information provided to the SPA Meteor Section from 2006 is presented and discussed. Events covered include: the radio Quadrantid maximum on January 3/4; an impressive fireball seen from parts of England, Belgium and the Netherlands at 22h53m51s UT on July 18, which was imaged from three EFN stations as well; the Southern delta-Aquarid and alpha-Capricornid activity from late July and early August; the radio Perseid maxima on August 12/13; confirmation that the October 5/6 video-meteor outburst was not observed by radio; visual and radio findings from the strong, bright-meteor, Orionid return in October; another impressive UK-observed fireball on November 1/2, with an oil painting of the event as seen from London; the Leonids, which produced a strong visual maximum around 04h-05h UT on November 18/19 that was recorded much less clearly by radio; radio and visual reports from the Geminids, with a note regarding NASA-observed Geminid lunar impact flashes; and the Ursid outburst recorded by various techniques on December 22.

  19. Mass distribution of meteoroids obtained by a meteor forward-scatter (MFS) radar method.

    NASA Astrophysics Data System (ADS)

    Cevolani, G.; Gabucci, M. F.

    1996-04-01

    The cumulative distributions of the number vs. duration of echoes belonging to main meteor showers (Lyrids, η-Aquarids, δ-Aquarids, Perseids, Orionids, Leonids, Geminids) and sporadic background were investigated using a forward-scatter (FS) continuous-wave meteor radar link operational during 1992 - 95 over the long baseline Bologna-Lecce in Italy. The trend of the mass distribution of particles in the quoted meteoroid streams was derived, and the values of the mass index s were compared for each meteor population with the steady-state condition. It was found that the mass index s generally increases towards long-duration echoes, but many of the observed meteor streams appear to have unstable populations. The values of the mass index of the sporadic complex are generally higher than the corresponding ones of meteor showers in the range of echo durations 0.1 ≤ T ≤ 10 s. This is a possible consequence of longer-lasting FS signals, indicating a shift of the mass distribution function vs. higher echo durations. Moreover, non-gravitational forces in connection with solar radiation pressure, Poynting-Robertson effect, solar-wind particle streaming, mutual collisions, etc., appear to be responsible for the observed widespread radiants and for unstable populations in the meteoroid streams.

  20. STS-87 crew in LC-39B white room during TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participates in the Terminal Countdown Demonstration Test (TCDT) at KSC. Standing, from left, Mission Specialist Winston Scott; Backup Payload Specialist Yaroslav Pustovyi, Ph.D., of the National Space Agency of Ukraine (NSAU); Payload Specialist Leonid Kadenyuk of NSAU; Pilot Steven Lindsey; Commander Kevin Kregel; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Mission Specialist Kalpana Chawla, Ph.D. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

  1. Orbits and emission spectra from the 2014 Camelopardalids

    NASA Astrophysics Data System (ADS)

    Madiedo, José M.; Trigo-Rodríguez, Josep M.; Zamorano, Jaime; Izquierdo, Jaime; de Miguel, Alejandro Sánchez; Ocaña, Francisco; Ortiz, José L.; Espartero, Francisco; Morillas, Lorenzo G.; Cardeñosa, David; Moreno-Ibáñez, Manuel; Urzáiz, Marta

    2014-12-01

    We have analysed the meteor activity associated with meteoroids of fresh dust trails of Comet 209P/LINEAR, which produced an outburst of the Camelopardalid meteor shower (IAU code #451, CAM) in 2014 May. With this aim, we have employed an array of high-sensitivity CCD video devices and spectrographs deployed at 10 meteor observing stations in Spain in the framework of the Spanish Meteor Network. Additional meteoroid flux data were obtained by means of two forward-scatter radio systems. The observed peak zenithal hourly rate was much lower than expected, of around 20 meteors h-1. Despite of the small meteor flux in the optical range, we have obtained precise atmospheric trajectory, radiant and orbital information for 11 meteor and fireball events associated with this stream. The ablation behaviour and low tensile strength calculated for these particles reveal that Camelopardalid meteoroids are very fragile, mostly pristine aggregates with strength similar to that of the Orionids and the Leonids. The mineral grains seem to be glued together by a volatile phase. We also present and discuss two unique emission spectra produced by two Camelopardalid bright meteors. These suggest a non-chondritic nature for these particles, which exhibit Fe depletion in their composition.

  2. Dynamical systems theory and applications

    NASA Astrophysics Data System (ADS)

    Awrejcewicz, Jan

    2006-08-01

    The 7th International Conference devoted to "Dynamical Systems-Theory and Applications" hold in 8-11 December, 2003 in Łódź, Poland, and it was organized by the staff of Department of Automatics and Biomechanics of the Technical University of Łódź. It was financially supported by the Rector of the Technical University of Łódź and the Department of Education and Physical Culture of the Łódź City Hall. The members of the International Scientific Committee included: Igor V. Andrianov (Dniepropetrovsk), Jan Awrejcewicz (Łódź), Iliya Blekhman (Sankt Petersburg), Roman Bogacz (Warszawa), Dick van Campen (Eindhoven), Zbigniew Engel (Kraków), Lothar Gaul (Stuttgart), Józef Giergiel (Kraków), Michał Kleiber (Warszawa), Vadim A. Krysko (Saratov), Włodzimierz Kurnik (Warszawa), Claude-Henri Lamarque (Lyon), Leonid I. Manevitch (Moscow), Jan Osiecki (Warszawa), Wiesaw Ostachowicz (Gdańsk), Ladislav Pust (Prague), Giuseppe Rega (Rome), Tsuneo Someya (Tokyo), Zbigniew Starczewski (Warszawa), Eugeniusz Świtoński (Gliwice), Andrzej Tylikowski (Warszawa), Tadeusz Uhl (Kraków), Aleksander F. Vakakis (Illinois), Józef Wojnarowski (Gliwice).

  3. STS-87 crew greet VIPs after successful landing at KSC

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Commander Kevin Kregel, center, shakes hands with the deputy director general of the National Space Agency of Ukraine (NSAU), Eduard Kuznetsov, at far right. Next to Kuznetsov is the Honorable Yuri Shcherbak, Ukraine's ambassador to the United States, standing with the president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, and NASA Administrator Daniel Goldin (center). Approaching the VIPs from the left of the photo are Mission Specialists Kalpana Chawla, Ph.D., and Takao Doi, Ph.D., of NASDA. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16- hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Pilot Steven Lindsey; Mission Specialist Winston Scott; and Payload Specialist Leonid Kadenyuk of NSAU. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  4. STS-87 crew and VIPs inspect the orbiter Columbia after landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 crew members regard the tiles underneath the orbiter Columbia shortly after its return to Runway 33 at Kennedy Space Center's Shuttle Landing Facility. Pointing to the tiles is the president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, who is standing next to NASA Administrator Daniel Goldin. STS-87 Commander Kevin Kregel, at right, looks on as Pilot Steve Lindsey follows behind him to continue inspecting the orbiter. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of NASDA; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  5. History of dermatologic surgery. From the beginnings to late antiquity.

    PubMed

    Marmelzat, W L

    1987-01-01

    We stop short, with Celsus, our glimpse of ancient dermatologic surgery in the West. As was stated at the beginning of the chapter, only a few examples and speculations are mentioned in this brief account. Much has gone unmentioned, including the contributions of great Eastern civilizations, such as ancient India, China, and Persia; the Bible; and the "ancient" inhabitants of the "new" world. We note especially the omission of the amazing ancient Hindu cosmetic operations that successfully employed rotating pedicle flaps in reconstructing amputated ears and noses. Important names before Celsus are missing from this account, especially the two Alexandrian physician-surgeons who flourished three centuries earlier--Herophilus (the Father of Anatomy) and Erasistratus (the Father of Physiology). Except for a few extant anatomic fragments, the works of Herophilus and Erasistratus are completely lost. We may with confidence, however, infer from the writings of Celsus and Galen that the brillant anatomy and physiology of the Alexandrian period made for good surgical diagnosis and practice. We must remember, too, that after Celsus' time, the slow disintergration of the Roman Empire took more than 500 years. This period of 500 years saw a number of important Roman physician-surgeons who contributed significantly with daring new operations and original surgical concepts and techniques: Heliodorus, Soranus, Rufus, Archigenes, Galen, Antyllus, Leonides, Oribasius, Aetius, Paulus, and others. The positive surgical contributions of these giants would be lost and rediscovered, many times.

  6. NASDA President Isao Uchida greets STS-87 Mission Specialist Takao Doi, Ph.D., after landing

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, chats with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34- minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  7. NASDA President Isao Uchida shakes hands with STS-87 Mission Specialist Takao Doi, Ph.D., after land

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, shakes hands with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program.

  8. Hydrocephalus according to Byzantine writers.

    PubMed

    Lascaratos, John G; Panourias, Ioannis G; Sakas, Damianos E

    2004-07-01

    To describe hydrocephalus, the techniques applied for its treatment by Byzantine physicians, and their later influence. A study and analysis of the original texts of the Byzantine medical writers, written in Greek, was undertaken. A comparison with current concepts also was made. Three eminent Byzantine physicians: Oribasius (4th century AD), Aetius (6th century AD), and Paul of Aegina (7th century AD) gave the first detailed information regarding hydrocephalus and its conservative and surgical treatment. These physicians, who were trained in Alexandria, quote the concepts of the now-lost works of the celebrated surgeons of the Pneumatic School of Alexandria Leonides and Heliodorus (1st century AD) and its follower Antyllus (2nd century AD). In the types of hydrocephalus they described, we identify the conditions currently known as cephalhematoma and subgaleal hematoma, for which conservative and surgical treatments were provided, and epidural hematoma, which was thought to be incurable. The term hydrocephalus was coined during the Hellenistic period. The clinical picture of the disease, however, as described by later Byzantine physicians, does not correspond to current concepts. The ideas of the Byzantine physicians were based on the ancient Hippocratic, Hellenistic, and Roman traditions, which influenced Arab medicine and then Western European medicine, thus constituting significant roots of modern neurosurgery.

  9. Kinematical parameters of the meteors from the results of the basic television observations during the period of the autumn solstice 2001

    NASA Astrophysics Data System (ADS)

    Kozak, P.; Rozhilo, O.; Taranukha, Ju.

    2012-12-01

    Results of kinematical processing of double-station TV meteor observations during a period of Autumn Equinox of 2001 are presented. "Introskop" TV systems equipped by high sensitive transmitting TV tubes of super-isocon type (Li-804), and photographic lenses Jupiter-3 had been used for the observations. The observations were carried out on September 21-22, 2001 simultaneously from two points placed at the distance of 54 km. We have registered 18 double-station meteors for the observational period. Kinematical parameters of meteors are presented, and the problem of precision of the observational data is discussed. The observational results are compared with the working list of meteor shower radiants of Meteor Data Center of International Astronomical Union. Established meteor showers from the list: Dayt. Kappa Leonids and October Capricornids, which had to be active during observational periods were confirmed by no one of 18 meteors. Another established shower named September epsilon Perseids could be confirmed by four meteors, but not surely because of significant deviations of control parameters. Also we have confirmed a few mini-showers, including one: sigma Orionids with possible enhancement of its activity time for three days.

  10. Recent Advances in Video Meteor Photometry

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.; Meachem, Terry; Cooke, William J.

    2003-01-01

    One of the most common (and obvious) problems with video meteor data involves the saturation of the output signal produced by bright meteors, resulting in the elimination of such meteors from photometric determinations. It is important to realize that a "bright" meteor recorded by intensified meteor camera is not what would be considered "bright" by a visual observer - indeed, many Generation II or III camera systems are saturated by meteors with a visual magnitude of 3, barely even noticeable to the untrained eye. As the relatively small fields of view (approx.30 ) of the camera systems captures at best modest numbers of meteors, even during storm peaks, the loss of meteors brighter than +3 renders the determination of shower population indices from video observations even more difficult. Considerable effort has been devoted by the authors to the study of the meteor camera systems employed during the Marshall Space Flight Center s Leonid ground-based campaigns, and a calibration scheme has been devised which can extend the useful dynamic range of such systems by approximately 4 magnitudes. The calibration setup involves only simple equipment, available to amateur and professional, and it is hoped that use of this technique will make for better meteor photometry, and move video meteor analysis beyond the realm of simple counts.

  11. Practical Meteor Stream Forecasting

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; Suggs, Robert M.

    2003-01-01

    Inspired by the recent Leonid meteor storms, researchers have made great strides in our ability to predict enhanced meteor activity. However, the necessary calibration of the meteor stream models with Earth-based ZHRs (Zenith Hourly Rates) has placed emphasis on the terran observer and meteor activity predictions are published in such a manner to reflect this emphasis. As a consequence, many predictions are often unusable by the satellite community, which has the most at stake and the greatest interest in meteor forecasting. This paper suggests that stream modelers need to pay more attention to the needs of this community and publish not just durations and times of maxima for Earth, but everything needed to characterize the meteor stream in and out of the plane of the ecliptic, which, at a minimum, consists of the location of maximum stream density (ZHR) and the functional form of the density decay with distance from this point. It is also suggested that some of the terminology associated with meteor showers may need to be more strictly defined in order to eliminate the perception of crying wolf by meteor scientists. An outburst is especially problematic, as it usually denotes an enhancement by a factor of 2 or more to researchers, but conveys the notion of a sky filled with meteors to satellite operators and the public. Experience has also taught that predicted ZHRs often lead to public disappointment, as these values vastly overestimate what is seen.

  12. Damping in the growth of plasma irregularities caused by meteoric dust particles in the equatorial E-region

    NASA Astrophysics Data System (ADS)

    Muralikrishna, Polinaya

    2016-07-01

    Two stream and gradient drift instability mechanisms operating in the E-region of the equatorial ionosphere can be affected by dust particles of meteoric origin. The dust particles can capture the ambient electrons and cause considerable increase in the loss rate of electrons thus affecting the growth rates and amplitudes of the plasma irregularities. The attachment of electrons on dust particles can increase the threshold velocities needed for the onset of two stream and gradient drift instability mechanisms responsible for the generation of Type I and Type II plasma irregularities respectively, observed in the equatorial E-region plasma. Also from simple theoretical considerations one can see that the growth rate and amplitude of both Type I and Type II irregularities can be reduced considerably by the meteoric dust particles by increasing the collision frequencies. Observation of persistence of Leonid meteor trails is probably due to the reduction in the wave amplitudes and their dependent diffusion rate caused by the electron bite outs produced by the ambient dust particles. In situ rocket observations also indicate that, under similar ambient conditions, the amplitudes of Type II irregularities observed in the lower E-region are considerably smaller than those observed at higher altitudes. This probably is a direct evidence for the effect of dust particles that dominate the lower E-region altitudes practically all the time.

  13. Asteroids, comets, Kuiper Belt objects, meteors: the ACM (AKM) 2002 perspective

    NASA Astrophysics Data System (ADS)

    Binzel, Richard P.

    2002-11-01

    An impressionistic overview is given on the state of science of Asteroider, Kometer, Meteorer (AKM), where the Swedish spelling is adopted in recognition of the origin of the ACM conference series. Asteroider (asteroids) are a field that has come of age to the point of asking sophisticated geological and geophysical questions based on dedicated spacecraft missions. Kometer (comets) are coming of age with a strong international emphasis toward new comet missions and ever increasing sophistication of Earth-based observations. K also stands for Kuiper belt objects, a field that wasn't invented when our conference series began but whose inclusion we embrace and recognize as being integral to our science. (Hence the recommendation that we adopt the moniker AKM to proclaim fully our inclusivity) KBOs are an emerging field, perhaps analogous to a fast growing child. The presently known number of KBOs is comparable to the number of known main-belt asteroids in 1900, suggesting that we are just beginning to learn about this region. Meteorer (meteors) is a rejuvenated field that has enjoyed spectacular recent successes in detailed predictions of the Leonid shower and in just recently recording the fall and recovering the Neuschwanstein meteorite. The future outlook portends the greatest advancement in K (kometer and KBOs) with broad interdisciplinary implications.

  14. Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; McNamara, H.

    2010-01-01

    Since early 2006 the Meteoroid Environment Office at NASA's Marshall Space Flight Center has been consistently monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 11 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-900 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated.

  15. Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2006 Geminids, 2007 Lyrids, and 2008 Taurids

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Suggs, R. M.; Swift, W. R.; Suggs, R. J.; Cooke, W. J.; Diekmann, A. M.; Koehler, H. M.

    2010-01-01

    Since early 2006 the Meteoroid Environment Office (MEO) at NASA s Marshall Space Flight Center has been consistently monitoring the Moon for impact flashes produced by meteoroids striking the lunar surface. During this time, several meteor showers have produced multiple impact flashes on the Moon. The 2006 Geminids, 2007 Lyrids, and 2008 Taurids were observed with average rates of 5.5, 1.2, and 1.5 meteors/hr, respectively, for a total of 12 Geminid, 12 Lyrid, and 12 Taurid lunar impacts. These showers produced a sufficient, albeit small sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. (2000) for the 1999 Leonids. An analysis of the Geminid, Lyrid, and Taurid lunar impacts is carried out herein in order to determine the luminous efficiency in the 400-800 nm wavelength range for each shower. Using the luminous efficiency, the kinetic energies and masses of these lunar impactors can be calculated.

  16. An Ongoing Program for Monitoring the Moon for Meteoroid Impacts

    NASA Astrophysics Data System (ADS)

    Cudnik, Brian; Saganti, Seth; Ali, Fazal; Ali, Salman; Beharie, Trevannie; Anugwom, Brittany

    2017-06-01

    Lunar meteor impacts are surprisingly frequent phenomena, with well over one hundred observable events occurring each year. Of these a little over half arise from members of annual meteor showers (e.g. Perseids, Leonids, etc.), with the rest being sporadic in origin. Five years ago, I introduced to the SAS Symposium the idea of observing lunar meteoroid impact phenomena and applying these observations to a space mission (LADEE-Lunar Atmosphere and Dust Environment Explorer) that launched the following year. Five years later I revisit and reintroduce the activities of the Association of Lunar and Planetary Observers-Lunar Meteoritic Impact Search (ALPO-LMIS) section and share some of the latest observations that have been received. For over 17 years now, ALPO has hosted the LMIS section, for which I have served as coordinator since its inception. In this paper, I will revisit the main ideas of the earlier paper, share some recent observations of lunar meteors, and provide new initiatives and projects interested persons can participate in.

  17. Meteors: A Delivery Mechanism of Organic Matter to The Early Earth

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Wilson, Mike A.; Packan, Dennis; Laux, Christophe O.; Krueger, Charles H.; Boyd, Iain, D.; Popova, Olga P.; Fonda, Mark; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    All potential exogenous pre-biotic matter arrived to Earth by ways of our atmosphere, where much material was ablated during a luminous phase called 1. meteors" in rarefied flows of high (up to 270) Mach number. The recent Leonid showers offered a first glimpse into the elusive physical conditions of the ablation process and atmospheric chemistry associated with high-speed meteors. Molecular emissions were detected that trace a meteor's brilliant light to a 4,300 K warm wake rather than to the meteor's head. A new theoretical approach using the direct simulation by Monte Carlo technique identified the source-region and demonstrated that the ablation process is critical in the heating of the meteor's wake. In the head of the meteor, organic carbon appears to survive flash heating and rapid cooling. The temperatures in the wake of the meteor are just right for dissociation of CO and the formation of more complex organic compounds. The resulting materials could account for the bulk of pre-biotic organic carbon on the early Earth at the time of the origin of life.

  18. STS-87 crew in LC-39B white room during TCDT

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crew of the STS-87 mission, scheduled for launch Nov. 19 aboard the Space Shuttle Columbia from pad 39B at Kennedy Space Center (KSC), participates in the Terminal Countdown Demonstration Test (TCDT) at KSC. Standing, from left, Mission Specialist Winston Scott; Backup Payload Specialist Yaroslav Pustovyi, Ph.D., of the National Space Agency of Ukraine (NSAU); Payload Specialist Leonid Kadenyuk of NSAU; Pilot Steven Lindsey; Commander Kevin Kregel; Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan; and Mission Specialist Kalpana Chawla, Ph.D. The TCDT is held at KSC prior to each Space Shuttle flight providing the crew of each mission opportunities to participate in simulated countdown activities. The TCDT ends with a mock launch countdown culminating in a simulated main engine cut-off. The crew also spends time undergoing emergency egress training exercises at the pad and has an opportunity to view and inspect the payloads in the orbiter's payload bay.

  19. Static experiments above 5 Mbar

    NASA Astrophysics Data System (ADS)

    Dubrovinskaia, Natalia

    2013-06-01

    The impact of high-pressure studies on fundamental physics and chemistry, and especially on the Earth and planetary sciences, has been enormous. While experiments in diamond anvil cells (DACs) at pressures of ~250 - 400 GPa are proven to be very difficult but possible, at higher static pressures any matter has not been investigated so until very recently [Ref. 1]. We have developed a method of synthesis of balls and semi-balls (of 10 to 50 μm in diameter) made of nanodiamond (with individual nano-particles of linear dimensions below 100 nm) and used them as second-stage or indentor-type anvils in conventional DACs. In experiments on rhenium, osmium, and gold we were able to generate pressures above 650 GPa [Ref. 1] and demonstrated crucial necessity of the ultra-high pressure measurements for accurate determination of the equation of state (EOS) of materials at extreme conditions. In collaboration with Leonid Dubrovinsky, Bayerisches Geoinstitut, University of Bayreuth; Vitali Prakapenka, University of Chicago; Artem Abukumov, University of Antwerp; and Michael Hanfland; ESRF, Grenoble.

  20. KSC-97PC1747

    NASA Image and Video Library

    1997-12-05

    STS-87 Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency (NASDA) of Japan greets a NASDA official shortly after the orbiter Columbia returned to KSC, touching down on Runway 33 at KSC's Shuttle Landing Facility. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  1. KSC-97PC1748

    NASA Image and Video Library

    1997-12-05

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, greets NASA Administrator Daniel Goldin, at right, as back-up Payload Specialist Yaroslav Pustovyi, also of NSAU, looks on. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D. of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  2. KSC-97PC1755

    NASA Image and Video Library

    1997-12-05

    STS-87 Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine (NSAU), at left, chats with NASA Administrator Daniel Goldin shortly after the landing of Columbia at Kennedy Space Center. Looking on is back-up Payload Specialist Yaroslav Pustovyi, also of NSAU. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; and Mission Specialists Winston Scott, Kalpana Chawla, Ph.D., and Takao Doi, Ph.D., of the National Space Development Agency of Japan. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  3. KSC-97PC1753

    NASA Image and Video Library

    1997-12-05

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, chats with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  4. KSC-97PC1754

    NASA Image and Video Library

    1997-12-05

    The president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, at left, shakes hands with STS-87 Mission Specialist Takao Doi, Ph.D., of NASDA, shortly after the landing of Columbia at Kennedy Space Center. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Commander Kevin Kregel; Pilot Steven Lindsey; Mission Specialists Winston Scott and Kalpana Chawla, Ph.D.; and Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  5. KSC-97PC1745

    NASA Image and Video Library

    1997-12-05

    The STS-87 crew pose in front of the orbiter Columbia shortly after landing on Runway 33 at KSC's Shuttle Landing Facility. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. From left to right are Mission Specialists Winston Scott and Takao Doi, Ph.D., of the National Space Development Agency of Japan; Commander Kevin Kregel; Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine; Mission Specialist Kalpana Chawla, Ph.D.; and Pilot Steven Lindsey. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  6. KSC-97PC1744

    NASA Image and Video Library

    1997-12-05

    STS-87 Commander Kevin Kregel, center, shakes hands with the deputy director general of the National Space Agency of Ukraine (NSAU), Eduard Kuznetsov, at far right. Next to Kuznetsov is the Honorable Yuri Shcherbak, Ukraine's ambassador to the United States, standing with the president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, and NASA Administrator Daniel Goldin (center). Approaching the VIPs from the left of the photo are Mission Specialists Kalpana Chawla, Ph.D., and Takao Doi, Ph.D., of NASDA. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, at KSC's Shuttle Landing Facility Runway 33, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Pilot Steven Lindsey; Mission Specialist Winston Scott; and Payload Specialist Leonid Kadenyuk of NSAU. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  7. KSC-97PC1746

    NASA Image and Video Library

    1997-12-05

    STS-87 crew members regard the tiles underneath the orbiter Columbia shortly after its return to Runway 33 at Kennedy Space Center's Shuttle Landing Facility. Pointing to the tiles is the president of the National Space Development Agency (NASDA) of Japan, Isao Uchida, who is standing next to NASA Administrator Daniel Goldin. STS-87 Commander Kevin Kregel, at right, looks on as Pilot Steve Lindsey follows behind him to continue inspecting the orbiter. STS-87 concluded its mission with a main gear touchdown at 7:20:04 a.m. EST Dec. 5, drawing the 15-day, 16-hour and 34-minute-long mission of 6.5 million miles to a close. Also onboard the orbiter were Mission Specialists Winston Scott; Kalpana Chawla, Ph.D.; and Takao Doi, Ph.D., of NASDA; along with Payload Specialist Leonid Kadenyuk of the National Space Agency of Ukraine. During the 88th Space Shuttle mission, the crew performed experiments on the United States Microgravity Payload-4 and pollinated plants as part of the Collaborative Ukrainian Experiment. This was the 12th landing for Columbia at KSC and the 41st KSC landing in the history of the Space Shuttle program

  8. Recent Advances in Video Meteor Photometry

    NASA Technical Reports Server (NTRS)

    Swift, Wesley R.; Suggs, Robert M.; Meachem, Terry; Cooke, William J.

    2003-01-01

    One of the most common (and obvious) problems with video meteor data involves the saturation of the output signal produced by bright meteors, resulting in the elimination of such meteors from photometric determinations. It is important to realize that a "bright" meteor recorded by intensified meteor camera is not what would be considered "bright" by a visual observer - indeed, many Generation II or III camera systems are saturated by meteors with a visual magnitude of 3, barely even noticeable to the untrained eye. As the relatively small fields of view (approx.30 ) of the camera systems captures at best modest numbers of meteors, even during storm peaks, the loss of meteors brighter than +3 renders the determination of shower population indices from video observations even more difficult. Considerable effort has been devoted by the authors to the study of the meteor camera systems employed during the Marshall Space Flight Center s Leonid ground-based campaigns, and a calibration scheme has been devised which can extend the useful dynamic range of such systems by approximately 4 magnitudes. The calibration setup involves only simple equipment, available to amateur and professional, and it is hoped that use of this technique will make for better meteor photometry, and move video meteor analysis beyond the realm of simple counts.

  9. Electromagnetic Properties of Impact-Generated Plasma, Vapor and Debris

    SciTech Connect

    Crawford, D.A.; Schultz, P.H.

    1998-11-02

    Plasma, vapor and debris associated with an impact or explosive event have been demonstrated in the laboratory to produce radiofrequency and optical electromagnetic emissions that can be diagnostic of the event. Such effects could potentially interfere with communications or remote sensing equipment if an impact occurred, for example, on a satellite. More seriously, impact generated plasma could end the life of a satellite by mechanisms that are not well understood and not normally taken into account in satellite design. For example, arc/discharge phenomena resulting from highly conductive plasma acting as a current path across normally shielded circuits may have contributed to the loss of the Olympus experimental communications satellite on August 11, 1993. The possibility of significant storm activity during the Leonid meteor showers of November 1998, 1999 and 2000 (impact velocity, 72 km/s) has heightened awareness of potential vulnerabilities from hypervelocity electromagnetic effects to orbital assets. The concern is justified. The amount of plasma, electrostatic charge and the magnitude of the resulting currents and electric fields scale nearly as the cube of the impact velocity. Even for microscopic Leonid impacts, the amount of plasma approaches levels that could be dangerous to spacecraft electronics. The degree of charge separation that occurs during hypervelocity impacts scales linearly with impactor mass. The resulting magnetic fields increase linearly with impactor radius and could play a significant role in our understanding of the paleomagnetism of planetary surfaces. The electromagnetic properties of plasma produced by hypervelocity impact have been exploited by researchers as a diagnostic tool, invoked to potentially explain the magnetically jumbled state of the lunar surface and blamed for the loss of the Olympus experimental communications satellite. The production of plasma in and around an impact event can lead to several effects: (1) the

  10. Photometric Calibration of Consumer Video Cameras

    NASA Technical Reports Server (NTRS)

    Suggs, Robert; Swift, Wesley, Jr.

    2007-01-01

    Equipment and techniques have been developed to implement a method of photometric calibration of consumer video cameras for imaging of objects that are sufficiently narrow or sufficiently distant to be optically equivalent to point or line sources. Heretofore, it has been difficult to calibrate consumer video cameras, especially in cases of image saturation, because they exhibit nonlinear responses with dynamic ranges much smaller than those of scientific-grade video cameras. The present method not only takes this difficulty in stride but also makes it possible to extend effective dynamic ranges to several powers of ten beyond saturation levels. The method will likely be primarily useful in astronomical photometry. There are also potential commercial applications in medical and industrial imaging of point or line sources in the presence of saturation.This development was prompted by the need to measure brightnesses of debris in amateur video images of the breakup of the Space Shuttle Columbia. The purpose of these measurements is to use the brightness values to estimate relative masses of debris objects. In most of the images, the brightness of the main body of Columbia was found to exceed the dynamic ranges of the cameras. A similar problem arose a few years ago in the analysis of video images of Leonid meteors. The present method is a refined version of the calibration method developed to solve the Leonid calibration problem. In this method, one performs an endto- end calibration of the entire imaging system, including not only the imaging optics and imaging photodetector array but also analog tape recording and playback equipment (if used) and any frame grabber or other analog-to-digital converter (if used). To automatically incorporate the effects of nonlinearity and any other distortions into the calibration, the calibration images are processed in precisely the same manner as are the images of meteors, space-shuttle debris, or other objects that one seeks to

  11. The Mesopause as a physical penetration boundary

    NASA Astrophysics Data System (ADS)

    Revelle, D. O.

    2005-09-01

    In this work we have analyzed the entry behavior of all known types of meteoroids using a single-body end height model in order to test their entry penetration into the earth's middle and upper atmosphere. We have utilized a new physically based model that incorporates a number of new features including a total power budget during entry as well as the very important processes of ablation and deceleration. More specifically, we have examined the meteoroid sizes and masses that are capable of terminating their visible flight at the Mesopause. In order to accomplish these calculations, we have assigned specific shape, shape change, angle of entry, radius, velocity, the kinetic energy removal D parameter of ReVelle, bulk density (or equivalently formulated in terms of uniform volume-weighted porosity), etc. We have further tested the reliability and done a test calibration of the model predictions utilizing an extreme entry case (for a Leonid bolide that penetrated to the Mesopause on November 15, 2001 and that was detected by photometry as well as by using infrasound). Finally, after assuming specific velocity limits for each group with the specific size limits being predicted by the model, we have also compared our predicted mass influx results (number per year on Earth versus initial mass) against recent Large Aperture Radar data obtained at the Arecibo Observatory by Janches (personal communication, 2003). Generally, quite small meteors are “stopped” at the Mesopause, but for the weakest materials, bodies as massive as ˜0.14 kg can be stopped above the Mesopause, especially at shallower entry angles. Generally reasonable agreement was found, but there are still a number of uncertainties as well. Eventually, this analysis should be redone using our advanced meteor modeling techniques including our triggered progressive fragmentation model, etc. [ReVelle, 2001a. Theoretical Leonid entry modeling, In: Warmbein, B., (Ed.), Proceedings of the Meteoroids 2001

  12. Optimization of Compact Array Configurations to Minimize Side-lobes for Two Cases: The LWA Phased-array Station and the New E-configuration for the EVLA

    NASA Astrophysics Data System (ADS)

    Kogan, Leonid; Owen, F.; Ott, J.; Cohen, A.

    2011-01-01

    An optimization algorithm designed by Leonid Kogan ( L. Kogan, Optimizing a Large Array Configuration to Minimize the Side lobes, IEEE Transactions on Antennas and Propagation, vol 48, NO 7, July 2000, p 1075) to minimize side-lobes in the point-spread response has been applied in the design of two new radio-interferometric arrays: (1) the most compact (E) configuration of EVLA and (2) the phased-array station for the Long Wavelength Array (LWA). Scientific programs for the EVLA's E-configuration includes galactic and Local HII, molecular gas, cosmic web, radio continum, radio lobes, SZ effect, cosmology and pulsar searches. The LWA will operate at frequencies from 10-88 MHz and will study a wide range of scientific programs including clusters of galaxies, high-redshift radio galaxies, pulsars, SNR's, extra-solar planets, solar physics and ionospheric physics. Both arrays need to be compact and to have the smallest side lobes possible. The E-configuration was designed to minimizes cost by requiring only one new railroad track in addition to the existing EVLA infrastructure. The shadowing factor achieved is reasonably good for a wide range of hour angles and declinations. The achieved side-lobe levels in the synthesized beam are no greater than 12% within the antenna primary beam for any operating VLA wavelength. For comparison, the VLA-D configuration has side-lobes near 60%. For the LWA station configuration, the sidelobes are never greater than 1.6% at any point in the sky regardless of phased direction or operating wavelength. Such small sidelobes for both arrays promise very high image fidelity for maximum scientific results.

  13. Meteoroids near the Earth-Moon system as inferred from temporal and spatial distribution of impacts detected by the lunar seismic network

    SciTech Connect

    Oberst, P.J.

    1989-01-01

    The meteoroid impacts detected by the lunar seismic station network are examined in terms of (a) the distribution of impact locations and energies, (b) the diurnal variation of impact rate, and (c) temporal clustering. Small meteoroids (estimated masses smaller than 1 kg) and large meteoroids (estimated masses larger than 1 kg) are found to differ significantly in their temporal distributions. Small meteoroids show strong clustering. Several known cometary showers are identified among the clusters; the Perseids, Leonids, Aquarids, Orionids, and Geminids being the most prominent. The majority of the detected objects approaches at high speeds from highly inclined orbits. In contrasts, large meteoroids travel predominantly in orbits of low inclination and show little clustering. The average impact flux of these large objects is estimated to be log{sub 10}n(E) = {minus}0.99 log{sub 10} E + 11.38 for the energy range 2 {times} 10{sup 11} J to 2 {times} 10{sup 12} J, where n is the cumulative number of meteoroids having kinetic energies greater than E, in Joule, impacting the lunar surface. This agrees within a factor of five with flux rates of terrestrially observed airwave objects (very large meteoroids) and flux rates estimated from lunar crater statistics. Sources of the small-mass meteoroids are suggested to be mostly long-period comets. The diurnal distribution of the detected large-mass meteoroids indicates that most of them do not represent high-density meteorites but low-density material too fragile to survive the terrestrial atmospheric entry. These large objects are probably derived from short-period comets and low-density members among the near-Earth asteroids.

  14. Theoretical Studies of Time-Resolved Photoelectron Spectra of IBr^-

    NASA Astrophysics Data System (ADS)

    Horvath, Samantha; McCoy, Anne B.; Pitzer, Russell M.

    2009-06-01

    In the present study, we examine the time-resolved photoelectron spectra of IBr^-. In the photodetachment studies performed by Sanov and co-workers and Lineberger and co-workers, the anionic species, prepared in its electronic ground state (^2Σ_{1/2}^+), is excited to either its \\Atilde' (^2Π_{3/2}) or \\Btilde (^2Σ_{1/2}^+) excited state, before electron photodetachment and dissociation on the \\Ctilde (^1Π_1) or higher-lying excited states of the neutral species, respectively. In this work, we use the electronic structure program Columbus to calculate the six lowest electronic states of IBr^- and the ten lowest Σ states of IBr at the MR-SO-CISD/aug-cc-pVDZ level of theory/basis, using relativistic core potentials for I and Br. Experimentally determined electronic states of IBr are also used. Vibrational eigenstates for these electronic states are calculated in a discrete variable representation, and propagation of the thermally populated \\Xtilde-state vibrational wave functions on either the \\Atilde' or \\Btilde electronic states of the anion is performed using a Lanczos scheme. We then take time-dependent overlaps between these propagated states and the vibrational eigenstates of the neutral surface. Results for IBr^- show good agreement with the experimental time-resolved spectra. Extensions to IBr^-(CO_2)_n (n < 2) will also be discussed. R. Mabbs, K. Pichugin, and A. Sanov, J. Chem. Phys., 2005 122, 174305 Leonid Sheps, Elisa M. Miller, and W. C. Lineberger (private communication) E. Wrede, S. Laubach, S. Schulenburg, A. Brown, E. R. Wouters, A. J. Orr-Ewing, and M. N. R. Ashfold, J. Chem. Phys., 2001, 114(6), 2629. D. T. Colbert and W. H. Miller, J. Chem. Phys., 1992, 96(3), 1982

  15. Some medical aspects of an 8-month's space flight.

    PubMed

    Atkov OYu

    1992-01-01

    In 1984 a 237-day space flight was performed on board the orbital complex Salyut-7-Soyuz-T with the crew members Leonid D. Kizim (Commander), Vladimnir A. Solovyov (Flight-Engineer), and Oleg Yu. Atkov (Cosmonaut Researcher). The major medical task was to continue the study of the acute stage of adaptation to weightlessness, phenomenology and mechanisms of changes in hemodynamics, metabolism and other functions. During flight, echocardiographic and biochemical measurements, vestibular and sensory studies were conducted extensively. In 1988-1989, the fourth prime crew performed its flight on the Mir orbital station. The crew consisted of: A.A. Volkov (Commander, Cr), S.K. Krikalyov (Flight-Engineer, FE) who were launched together with J.L. Cretien on November 26, 1988 as well as V.V. Polyakov (physician, cosmonaut-researcher, CP) who was in orbit until August 29, 1988 as a member of the third and fourth expeditions. Cr and FE remained in orbit for 151 days and CP for 421 days. Now we have 4 people experiencing 8 months space flight. The countermeasures included regular exercises on a treadmill and bicycle ergometer, use of G-suits and lower body negative pressure (LBNP) training at the final stage. The cosmonauts exercised for a hour twice a day for 3 days on end and then had an "active rest" day. On the recovery day the cosmonauts were recommended to take water-salt supplements according to the following protocol: 2.7 g NaCl in 300 ml liquid during lunch and dinner plus 1.8 g NaCl in 150 ml liquid immediately before they began preparing for the descent (after they donned their space suits). During re-entry the cosmonauts had an anti-G suit on (without bladders).

  16. SURVEYING THE DYNAMIC RADIO SKY WITH THE LONG WAVELENGTH DEMONSTRATOR ARRAY

    SciTech Connect

    Lazio, T. Joseph W.; Clarke, Tracy E.; Lane, W. M.; Gross, C.; Kassim, N. E.; Hicks, B.; Polisensky, E.; Stewart, K.; Ray, P. S.; Wood, D.; York, J. A.; Kerkhoff, A.; Dalal, N. Paravastu; Cohen, A. S.; Erickson, W. C.

    2010-12-15

    This paper presents a search for radio transients at a frequency of 73.8 MHz (4 m wavelength) using the all-sky imaging capabilities of the Long Wavelength Demonstrator Array (LWDA). The LWDA was a 16-dipole phased array telescope, located on the site of the Very Large Array in New Mexico. The field of view of the individual dipoles was essentially the entire sky, and the number of dipoles was sufficiently small that a simple software correlator could be used to make all-sky images. From 2006 October to 2007 February, we conducted an all-sky transient search program, acquiring a total of 106 hr of data; the time sampling varied, being 5 minutes at the start of the program and improving to 2 minutes by the end of the program. We were able to detect solar flares, and in a special-purpose mode, radio reflections from ionized meteor trails during the 2006 Leonid meteor shower. We detected no transients originating outside of the solar system above a flux density limit of 500 Jy, equivalent to a limit of no more than about 10{sup -2} events yr{sup -1} deg{sup -2}, having a pulse energy density {approx}>1.5 x 10{sup -20} J m{sup -2} Hz{sup -1} at 73.8 MHz for pulse widths of about 300 s. This event rate is comparable to that determined from previous all-sky transient searches, but at a lower frequency than most previous all-sky searches. We believe that the LWDA illustrates how an all-sky imaging mode could be a useful operational model for low-frequency instruments such as the Low Frequency Array, the Long Wavelength Array station, the low-frequency component of the Square Kilometre Array, and potentially the Lunar Radio Array.

  17. Meteor light curves: the relevant parameters

    NASA Astrophysics Data System (ADS)

    Brosch, N.; Helled, Ravit; Polishook, D.; Almoznino, E.; David, N.

    2004-11-01

    We investigate a uniform sample of 113 light curves of meteors collected at the Wise Observatory in 2002 November during a campaign to observe the Leonid meteor shower. We use previously defined descriptors, such as the classical skewness parameter F and a recently defined pointedness variable P, along with a number of other measurable or derived quantities, in order to explore the parameter space in search of meaningful light curve descriptors. In comparison with previous publications, we make extensive use of statistical techniques to reveal links among the various parameters and to understand their relative importance. In particular, we show that meteors with long-duration trails rise slowly to their maximal brightness and also decay slowly from the peak, while showing milder flaring than other meteors. Early skewed meteors, with their peak brightness in the first half of the light curve, show a fast rise to the peak. We show that the duration of the luminous phase of the meteor is the most important variable differentiating among the 2002 meteor trails. The skewness parameter F, which is widely used in meteor light curve analyses, appears only as the second or third in order of importance in explaining the variance among the observed light curves, with the most important parameter being related to the duration of the meteor light-producing phase. We suggest that the pointedness parameter P could possibly be useful in describing differences among meteor showers, perhaps by being related to the different compositions of meteoroids, and also in comparing observations to model light curves. We compare the derived characteristics of the 2002 meteors with model predictions and conclude that more work is required to define a consistent set of measurable and derived light-curve parameters that would characterize the light production from meteors. We suggest that meteor observers should consider publishing more characterizing parameters from the light curves they

  18. Dynasonde Measurements of Ionospheric Meteor Effects

    NASA Astrophysics Data System (ADS)

    Berkey, F. T.; Sikdar, P.; Fish, C. S.; Jones, O.; Tsai, L.; Yen, C.

    2002-12-01

    The ionization created when meteoric particles impinge on the upper atmosphere has been studied extensively, both with optical methods and by radar techniques. Traditionally, meteor radars have been configured as dedicated, fixed-frequency systems that operate in the HF/VHF bands and are employed to measure winds and other parameters in the mesosphere-lower thermosphere region. It has long been recognized that ionosondes are capable of detecting meteor ionization although the sparse sounding format of most synoptic instruments does not facilitate a rigorous analysis of meteor ionization effects. Furthermore, most ionosonde-based studies have focused on meteor shower intervals when the meteor ionization is especially prominent (e.g. Chandra et. al., 2001). However, the capabilities of digital ionosondes such as the NOAA dynasonde allow the detailed study of various parameters of the meteor-induced ionization such as amplitude, polarization and spatial location, in addition to the time-of-flight, as a function of time and frequency. In this report, we will examine meteor ionization recorded by dynasondes located at Bear Lake (Utah) and Halley (Antarctica) demonstrating that these ionogram data can be used to distinguish between underdense and overdense meteor ionization. Other characteristics of the meteor-induced ionization, such as spatial location and Doppler velocity will also be presented. The dynasonde operated at the USU Bear Lake Observatory (42° N, 111° W) detects a large flux of meteor echoes and will be the primary source of data for this study. Chandra, H., et. al., Sporadic-E associated with the Leonid meteor shower event of November 1998 over low and equatorial latitudes, Annales. Geophys., 19, 59-69, 2001.

  19. Hydrogen emission in meteors as a potential marker for the exogenous delivery of organics and water.

    PubMed

    Jenniskens, Peter; Mandell, Avram M

    2004-01-01

    We detected hydrogen Balmer-alpha (H(alpha)) emission in the spectra of bright meteors and investigated its potential use as a tracer for exogenous delivery of organic matter. We found that it is critical to observe the meteors with high enough spatial resolution to distinguish the 656.46 nm H(alpha) emission from the 657.46 nm intercombination line of neutral calcium, which was bright in the meteor afterglow. The H(alpha) line peak stayed in constant ratio to the atmospheric emissions of nitrogen during descent of the meteoroid. If all of the hydrogen originates in the Earth's atmosphere, the hydrogen atoms are expected to have been excited at T = 4400 K. In that case, we measured an H(2)O abundance in excess of 150 +/- 20 ppm at 80-90 km altitude (assuming local thermodynamic equilibrium in the air plasma). This compares with an expected <20 ppm from H(2)O in the gas phase. Alternatively, meteoric refractory organic matter (and water bound in meteoroid minerals) could have caused the observed H(alpha) emission, but only if the line is excited in a hot T approximately 10000 K plasma component that is unique to meteoric ablation vapor emissions such as Si(+). Assuming that the Si(+) lines of the Leonid spectrum would need the same hot excitation conditions, and a typical [H]/[C] = 1 in cometary refractory organics, we calculated an abundance ratio [C]/[Si] = 3.9 +/- 1.4 for the dust of comet 55P/Tempel-Tuttle. This range agreed with the value of [C]/[Si] = 4.4 measured for comet 1P/Halley dust. Unless there is 10 times more water vapor in the upper atmosphere than expected, we conclude that a significant fraction of the hydrogen atoms in the observed meteor plasma originated in the meteoroid.

  20. On 45 Years of Space Plasma Research

    NASA Astrophysics Data System (ADS)

    Kelley, M. C.

    2011-12-01

    After 47 years of immersion in space physics, I have many stories to tell, some of which are not suitable for all audiences and will remain untold today. But after a few such tales, I will recount the most satisfying research I have done and then outline a new book I am working on entitled "The Earth's Electric Field". I also will outline five sources of electric fields: thunderstorms, motions of the atmosphere, the solar wind, the magnetosphere, and wave phenomena. The most satisfying work I have published involves proof that the Earth was hit by a comet in 1908, studies of the long-lasting meteor trail during Leonids1998/9, and results of barium/TMA releases. On the human side, the most satisfying work has been with Cornell students, both undergraduate and graduate. Although many books have been written on the Earth's magnetic field, to my knowledge, none have been written on the electric field. This is not surprising since Gauss first noted that the Earth is a giant magnet hundreds of years ago. The first evidence of an electric field in the atmosphere was provided by Ben Franklin with his kite/thunderstorm experiments. We began considering the possibility of an electric field in space about 50 years ago, using the motion of auroral patches. Then, in the 1960s, Forrest Mozer and Ulf Fahleson showed that the electric field could be measured using rockets and, eventually, satellites. Luckily, I was Forrest's second student and Ulf was in Berkeley for a year, so I was in the perfect place for a graduate student. Thus began the quest for knowledge of the Earth's electric field, which continues today.

  1. Properties of meteoroids from different classes of parent bodies

    NASA Astrophysics Data System (ADS)

    Borovička, Jiří

    2007-05-01

    Meteoroids are small near-Earth objects (< 10 m) which can be detected as meteors in the Earth's atmosphere. Meteor observations provide us with meteoroid orbits and can be also used to infer physical properties and chemical composition of meteoroids. Most meteoroids are fragments of either comets or asteroids. Direct link to the actual parent body is possible in case of meteoroid streams. In other cases, the type of orbit can indicate the asteroidal or cometary origin of the meteoroid. In this review, the properties (structure, mechanical strength, composition) of parent comets and asteroids will be discussed on the basis of meteor observations. The alternation of meteoroids in interplanetary space will be also discussed. Perseid and Leonid streams are typical representatives of cometary dust material originating in Halley type comets. Cometary dust can be characterized by low strength, low density (< 1 g /cm3) and high porosity. The Fe/Mg ratio is lower than chondritic. There are, however, mm-sized pieces of material embedded in comets with much higher strength. Also the irradiation cometary crust is much stronger than normal cometary material. The crust is also altered chemically, being depleted in Na. The Giacobinid stream is a representative of Jupiter family cometary material. This material seems to be even weaker than the Halley-type material. The Taurid meteoroid complex is related to comet Encke and possibly to several asteroids. The parent body of the Geminid stream is asteroid 3200 Phaethon. The Geminid meteoroids are significantly stronger than typical cometary meteoroids and are depleted in Na but this is a consequence of low perihelion distance of the stream (0.14 AU). The Fe/Mg ratio of Geminids is cometary and Phaethon is likely an extinct comet. Similar situation is with the Quadrantid stream and its parent asteroid 2003 EH1. The asteroidal meteoroids are, of course, stronger than cometary ones; nevertheless, they are much weaker than recovered

  2. Hydrogen emission in meteors as a potential marker for the exogenous delivery of organics and water

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Mandell, Avram M.

    2004-01-01

    We detected hydrogen Balmer-alpha (H(alpha)) emission in the spectra of bright meteors and investigated its potential use as a tracer for exogenous delivery of organic matter. We found that it is critical to observe the meteors with high enough spatial resolution to distinguish the 656.46 nm H(alpha) emission from the 657.46 nm intercombination line of neutral calcium, which was bright in the meteor afterglow. The H(alpha) line peak stayed in constant ratio to the atmospheric emissions of nitrogen during descent of the meteoroid. If all of the hydrogen originates in the Earth's atmosphere, the hydrogen atoms are expected to have been excited at T = 4400 K. In that case, we measured an H(2)O abundance in excess of 150 +/- 20 ppm at 80-90 km altitude (assuming local thermodynamic equilibrium in the air plasma). This compares with an expected <20 ppm from H(2)O in the gas phase. Alternatively, meteoric refractory organic matter (and water bound in meteoroid minerals) could have caused the observed H(alpha) emission, but only if the line is excited in a hot T approximately 10000 K plasma component that is unique to meteoric ablation vapor emissions such as Si(+). Assuming that the Si(+) lines of the Leonid spectrum would need the same hot excitation conditions, and a typical [H]/[C] = 1 in cometary refractory organics, we calculated an abundance ratio [C]/[Si] = 3.9 +/- 1.4 for the dust of comet 55P/Tempel-Tuttle. This range agreed with the value of [C]/[Si] = 4.4 measured for comet 1P/Halley dust. Unless there is 10 times more water vapor in the upper atmosphere than expected, we conclude that a significant fraction of the hydrogen atoms in the observed meteor plasma originated in the meteoroid.

  3. List of Organizing Committees and Conference Programme

    NASA Astrophysics Data System (ADS)

    2012-03-01

    Organizers Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH Romanian Neutron Scattering Society Sponsors Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH Comenius University in Bratislava, Slovakia Institute of Macromolecular Chemistry AS CR, Czech Republic Programme Committee Valentin Gordely (chairman)Joint Institute for Nuclear Research, Russia Heinrich StuhrmannGermany Jose TeixeiraLaboratoire Leon Brillouin, France Pavel ApelJoint Institute for Nuclear Research, Russia Pavol BalgavyComenius University in Bratislava, Slovakia Alexander BelushkinJoint Institute for Nuclear Research, Russia Georg BueldtInstitute of Structural Biology and Biophysics (ISB), Germany Leonid BulavinTaras Shevchenko National University of Kyiv, Ukraine Emil BurzoBabes-Bolyai University, Romania Vadim CherezovThe Scripps Research Institute, Department of Molecular Biology, USA Ion IonitaRomanian Society of Neutron Scattering, Romania Alexei KhokhlovMoscow State University, Russia Aziz MuzafarovInstitute of Synthetic Polymeric Materials, Russian Academy of Sciences, Russia Alexander OzerinInstitute of Synthetic Polymeric Materials, Russian Academy of Sciences, Russia Gerard PepyResearch Institute for Solid State Physics and Optics, Hungary Josef PlestilInstitute of Macromolecular Chemistry CAS, Czech Republic Aurel RadulescuJuelich Centre for Neutron Science JCNS, Germany Maria BalasoiuJoint Institute for Nuclear Research, Russia Alexander KuklinJoint Institute for Nuclear Research, Russia Local Organizing Committee Alexander Kuklin - Chairman Maria Balasoiu - Co-chairman Tatiana Murugova - Secretary Natalia Malysheva Natalia Dokalenko Julia Gorshkova Andrey Rogachev Oleksandr Ivankov Dmitry Soloviev Lilia Anghel Erhan Raul The PDF also contains the Conference Programme.

  4. Lunar and Planetary Science XXXVI, Part 6

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contents include the following: A Model for Multiple Populations of Presolar Diamonds. Characterization of Martian North Polar Geologic Units Using Mars Odyssey THEMIS Data. Effect of Flow on the Internal Structure of the Martian North Polar Layered Deposits. Elemental Abundance Distributions in Basalt Clays and Meteorites: Is It a Biosignature? Early Results on the Saturn System from the Composite Infrared Spectrometer. NanoSIMS D/H Imaging of Isotopically Primitive Interplanetary Dust Particles. Presolar (Circumstellar and Interstellar) Phases in Renazzo: The Effects of Parent Body Processing. Catastrophic Disruption of Hydrated Targets: Implications for the Hydrated Asteroids and for the Production of Interplanetary Dust Particles. Chemical and Mineralogical Analyses of Particles from the Stratospheric Collections Coinciding with the 2002 Leonid Storm and the 2003 Comet Grigg-Skjellerup Trail Passage. An Analysis of the Solvus in the CaS-MnS System. ESA s SMART-1 Mission at the Moon: First Results, Status and Next Steps. Europa Analog Ice-splitting Measurements and Experiments with Ice-Hunveyor on the Frozen Balaton-Lake, Hungary. Chromium on Eros: Further Evidence of Ordinary Chondrite Composition. Dust Devil Tracks on Mars: Observation and Analysis from Orbit and the Surface. Spatial Variation of Methane and Other Trace Gases Detected on Mars: Interpretation with a General Circulation Model. Mars Water Ice and Carbon Dioxide Seasonal Polar Caps: GCM Modeling and Comparison with Mars Express Omega Observations. Component Separation of OMEGA Spectra with ICA. Clathrate Formation in the Near-Surface Environment of Titan. Space Weathering: A Proposed Laboratory Approach to Explaining the Sulfur Depletion on Eros. Sample Collection from Small Airless Bodies: Examination of Temperature Constraints for the TGIP. Sample Collector for the Hera Near-Earth Asteroid Sample Return Mission. A Rugged Miniature Mass-Spectrometer for Measuring Aqueous Geochemistry on Mars

  5. Mineral and Rock Physics Focus Group Selects Kantor for 2008 Graduate Research Award

    NASA Astrophysics Data System (ADS)

    McCammon, Catherine

    2009-03-01

    The Mineral and Rock Physics focus group has selected Innokenty Kantor as the recipient of the 2008 Graduate Research Award. Kantor pursued his Ph.D. in high-pressure mineral physics at the Bayerisches Geoinstitut, University of Bayreuth, Germany, under the supervision of Leonid Dubrovinsky and Catherine McCammon, and he successfully defended his thesis, entitled “High-pressure and high-temperature structural and electronic properties of (Mg, Fe)O and FeO,” in July 2007. Kantor came to Germany with a strong theoretical background after gaining a master's diploma with honors at Moscow State University, Russia. At the University of Bayreuth, he developed experimental experience by mastering the challenging techniques of diamond anvil cell experimentation, Mössbauer spectroscopy, X-ray and neutron diffraction, and X-ray absorption spectroscopy. Highlights of Kantor's thesis research include the discovery that the rhombohedral distortion in iron oxide (FeO) and magnesium iron oxide ((Mg, Fe)O) does not coincide with the magnetic ordering transition (contrary to what had been assumed for many years); a full description of spin crossover in (Mg, Fe)O above 50 gigapascals including the effect of short-range order; and a new high-pressure monoclinic modification of FeO that may change the interpretation of the B1 → B8 (rock salt to nickel arsenide structure) transition at high pressure and temperature. All of these results have had a significant impact on the research field and influenced models for the behavior of FeO and (Mg, Fe)O at high pressure. Kantor's achievements have been recognized by a number of other awards, most recently the E.ON Bayern Kulturpreis, awarded for one of the best doctoral theses in Bavaria across all research fields.

  6. Hydrogen emission in meteors as a potential marker for the exogenous delivery of organics and water

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Mandell, Avram M.

    2004-01-01

    We detected hydrogen Balmer-alpha (H(alpha)) emission in the spectra of bright meteors and investigated its potential use as a tracer for exogenous delivery of organic matter. We found that it is critical to observe the meteors with high enough spatial resolution to distinguish the 656.46 nm H(alpha) emission from the 657.46 nm intercombination line of neutral calcium, which was bright in the meteor afterglow. The H(alpha) line peak stayed in constant ratio to the atmospheric emissions of nitrogen during descent of the meteoroid. If all of the hydrogen originates in the Earth's atmosphere, the hydrogen atoms are expected to have been excited at T = 4400 K. In that case, we measured an H(2)O abundance in excess of 150 +/- 20 ppm at 80-90 km altitude (assuming local thermodynamic equilibrium in the air plasma). This compares with an expected <20 ppm from H(2)O in the gas phase. Alternatively, meteoric refractory organic matter (and water bound in meteoroid minerals) could have caused the observed H(alpha) emission, but only if the line is excited in a hot T approximately 10000 K plasma component that is unique to meteoric ablation vapor emissions such as Si(+). Assuming that the Si(+) lines of the Leonid spectrum would need the same hot excitation conditions, and a typical [H]/[C] = 1 in cometary refractory organics, we calculated an abundance ratio [C]/[Si] = 3.9 +/- 1.4 for the dust of comet 55P/Tempel-Tuttle. This range agreed with the value of [C]/[Si] = 4.4 measured for comet 1P/Halley dust. Unless there is 10 times more water vapor in the upper atmosphere than expected, we conclude that a significant fraction of the hydrogen atoms in the observed meteor plasma originated in the meteoroid.

  7. The FeO Nightglow

    NASA Astrophysics Data System (ADS)

    Saran, D. V.; Slanger, T. G.

    2010-12-01

    Emission from the FeO molecule is a long-sought feature of the terrestrial nightglow. Current work in analyzing data from the OSIRIS spectrometer on the Odin satellite and the sky spectra from the ESI spectrograph on the Keck II telescope demonstrate that quasi-continuous emission near 600 nm can be identified as to be from excited FeO, by comparison with laboratory spectra obtained from the reaction between Fe and O3 [West and Broida, 1975; Jenniskens et al., 2000] and meteor trains. This emission is a ubiquitous feature in astronomical sky spectra obtained both with ESI and with the UVES/VLT system in Paranal, Chile. Integrated areas of the band profile in the 560-620 nm region with ESI show that the overhead continuum intensity is 3-4 times brighter than the sodium 589 nm lines, although the FeO emission extends well beyond 620 nm, and may reach several hundred Rayleighs. The temporal behavior of the FeO emission is closely related to that of both the sodium emission and the OH Meinel bands. This is not surprising given that all three of these nightglow emissions involve reaction with ozone. The temporal behavior needs to be modeled using global emission models because of the complexities of the intermediate reactions involved in generating the emitting states of FeO, Na and OH. Acknowledgements DVS was supported by NSF Aeronomy and CEDAR postdoc fellowship award, NSF grant ATM-0924781. TGS was supported by grant ATM-0637433 from NSF Aeronomy. References Jenniskens P., Lacey M., Allan B. J., Self D. E., Plane J. M. C., 2000, FeO "Orange Arc" emission detected in optical spectrum of Leonid persistent train. Earth, Moon and Planets 82-83, 429-438 West, J. B. and Broida, H.P.,1975, Chemiluminescence and photoluminescence of diatomic iron oxide. Journal of Chemical Physics, 62, 2566-2574.

  8. Lunar and Planetary Science XXXVI, Part 6

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contents include the following: A Model for Multiple Populations of Presolar Diamonds. Characterization of Martian North Polar Geologic Units Using Mars Odyssey THEMIS Data. Effect of Flow on the Internal Structure of the Martian North Polar Layered Deposits. Elemental Abundance Distributions in Basalt Clays and Meteorites: Is It a Biosignature? Early Results on the Saturn System from the Composite Infrared Spectrometer. NanoSIMS D/H Imaging of Isotopically Primitive Interplanetary Dust Particles. Presolar (Circumstellar and Interstellar) Phases in Renazzo: The Effects of Parent Body Processing. Catastrophic Disruption of Hydrated Targets: Implications for the Hydrated Asteroids and for the Production of Interplanetary Dust Particles. Chemical and Mineralogical Analyses of Particles from the Stratospheric Collections Coinciding with the 2002 Leonid Storm and the 2003 Comet Grigg-Skjellerup Trail Passage. An Analysis of the Solvus in the CaS-MnS System. ESA s SMART-1 Mission at the Moon: First Results, Status and Next Steps. Europa Analog Ice-splitting Measurements and Experiments with Ice-Hunveyor on the Frozen Balaton-Lake, Hungary. Chromium on Eros: Further Evidence of Ordinary Chondrite Composition. Dust Devil Tracks on Mars: Observation and Analysis from Orbit and the Surface. Spatial Variation of Methane and Other Trace Gases Detected on Mars: Interpretation with a General Circulation Model. Mars Water Ice and Carbon Dioxide Seasonal Polar Caps: GCM Modeling and Comparison with Mars Express Omega Observations. Component Separation of OMEGA Spectra with ICA. Clathrate Formation in the Near-Surface Environment of Titan. Space Weathering: A Proposed Laboratory Approach to Explaining the Sulfur Depletion on Eros. Sample Collection from Small Airless Bodies: Examination of Temperature Constraints for the TGIP. Sample Collector for the Hera Near-Earth Asteroid Sample Return Mission. A Rugged Miniature Mass-Spectrometer for Measuring Aqueous Geochemistry on Mars

  9. Shooting Stars over China

    NASA Astrophysics Data System (ADS)

    Hodges, John

    International cultural exchange and education in the sciences and arts is one of the chief aims of the British Council (BC). The 1998 Leonids Meteor Shower was recognised by the BC in China as an event that would offer an opportunity, both to promote the public understanding of space science at an international level, and to encourage on-going cultural links between the United Kingdom and China. Predictions suggested that the 1998 shower, which was likely to be the most intense for more than three decades, would be best viewed in north-east Asia. The BC contracted the Orbital Mechanics Educational Network, an independent organisation that promotes space education amongst young people, to organise several activities aimed particularly at teenagers. The culmination of the project was a visit to Beijing by a party of British teenagers, to take part in meteor observation at China's Mi Yun Observatory. The paper focusses on the practicalities of organising and running such a project and reports on the achievements and shortcomings of the overall venture. It also reports on the observations and findings that were made by the UK group and their Chinese student partners, all of whom were observing a meteor shower for the first time. It reports on the techniques of observing that were tried, the observations themselves and the findings that were made by the group. It also offers advice to those who might wish to set up similar bi-lateral ventures, particularly with China and the UK, and outlines plans to continue and improve the relationships that have been established. (Please note: I realise this is topic not directly covered by the Conference, but how the subject of the meteor phenomenon in particular and, for that matter, science in general is conveyed to the " man in the street" should be important to all scientists, not least because they depend on external funding and public goodwill! Perhaps a suitable slot can be made for this presentation on Tuesday, which is the

  10. Physical characteristics of the meteoroids by the results of combined radar and optical observations

    NASA Astrophysics Data System (ADS)

    Mirhusen, Narziev

    This paper proposes a method determining of the light and ionization curves by the results of combined radio - TV observations meteors in 1978-1980 in Hissar Astronomical Observatory of the Institute of Astrophysics of Sciences of Tajikistan, the calculation results of photographic and radar meteoroid mass and analysis of the shape of light curves of meteors within the theory of evaporation and the theory of the quasi-continuous fragmentation. The photographic meteoroid mass from the light curve were defined: a) by the value of maximum luminescence intensity at the height hm and b) by the integration light curve. It is based on analysis of the data of the mass were obtained correction factor that takes into account the effect of fragmentation and other factors to determine the mass of meteoroids first method. Average value of the mass of meteoroids calculated by the light curve for meteors with magnitude M≤1 is 19.10-3 g, and the average value of the mass found on magnitude of the luminescence intensity at the height the maximum brightness consist 18.2.10-3 that is in satisfactory agreement. The meteoroid’s masses was calculated also radio method by value of maximum linear electron density at the height of maximum ionization (n). The framework of the classical theory and the theory quasi-continuous fragmentation, the shape of the light curves of simultaneous radio - optical meteors were analyzed. It is shown that the main mechanism of ablation 60% of simultaneous radio - optical meteors is a quasi-continuous fragmentation. The bulk density and porosity of showers and sporadic meteoroids were determined. Found that the Geminids meteoroids and δ-Aquariids have the largest bulk densities (δo = 3.6 g/cm3). A meteoroids of the showers Orionids and Leonids have the lowest bulk density (δo ≤ 0.6 g/cm3), and the highest value of the porosity (60 ≤ K ≤ 80%). The mass fragments of flow and sporadic meteoroids lie in the range of 5.10-8÷10-5g.

  11. Dust Trails of SP/Tuttle and the Unusual Outbursts of the Ursid Shower

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Lyytinen, E.; deLignie, M. C.; Johannink, C.; Jobse, K.; Schievink, R.; Langbroek, M.; Koop, M.; Gural, P.; Wilson, M.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Halley-type comets tend to have a series of dust trails that remain spatially correlated for extended periods of time, each dating from a specific return of the comet. Encounters with 1 - 9 revolution old individual dust trails of 55P/Tempel-Tuttle have led to well recognized Leonid shower maxim, the peak time of which was well predicted by recent models. Now. we used the same model to calculate the position of dust trails of comet Shuttle, a Halley-type comet in an (approximately) 13.6 year orbit passing just outside of Earth's orbit. We discovered that the meteoroids tend to be trapped in the 14:12 mean motion resonance with Jupiter, while the comet librates in a slightly shorter period orbit around the 13:15 resonance. It takes six centuries to change the orbit enough to intersect Earth's orbit. During that time, the meteoroids and comet separate in mean anomaly by six years. thus explaining the unusual aphelion occurrences of Ursid outbursts. The resonances also prevent dispersion, so that the dust trail encounters (specifically, from dust trails of AD 1378 - 1405) occur only in one year in each orbit. We predicted enhanced activity on December 22, 2000, at around 7:29 and 8:35 UT (universal time) from dust trails dating to the 1405 and 1392 return, respectively. This event was observed from California using video and photographic techniques. At the same time, five Global-MS-Net stations in Finland, Japan and Belgium counted meteors using forward meteor scatter. The outburst peaked at 8:06:07 UT, December 22, at Zenith Hourly Rate (approx.) 90 per hour. The Ursid rates were above half peak intensity during 4.2 hours. This is only the second Halley type comet for which a meteor outburst can be dated to a specific return of the parent comet, and traces their presence back form 9 to at least 45 revolutions of the comet. New orbital elements of Ursid meteoroids are presented. We find that most orbits do scatter around the anticipated positions, confirming the link

  12. Micrometeorites from central Antarctic snow : the CONCORDIA-Collection.

    NASA Astrophysics Data System (ADS)

    Duprat, J.; Engrand, C.; Maurette, M.; Gounelle, M.; Kurat, G.

    extremely low at Dome C, it is technically possible to exploit large area (several tens m2.year) of annual snow layers formed up to 3 centuries ago, searching for particles from historical meteors showers such as the Leonids. [1] E. Anders and N. Grevesse, Geochim. Cosmochim. Acta (1989), 53, 197-214. [2] G. Kurat et al., Geochim. Cosmochim. Acta (1994), 58, 3879-3904. [3] F. J. M. Rietmeijer, in Planetary materials, M.s.o. America, Editor. 1998, Papike, J.-J.: Washington, D.C.

  13. Modularity and anti-modularity in networks with arbitrary degree distribution

    PubMed Central

    2010-01-01

    and modularity) provides the opportunity to create surrogates for biological and technological networks, and to test hypotheses about the processes that gave rise to them. We find that many celebrated network properties may be a consequence of the way in which these networks grew, rather than a necessary consequence of how they work or function. Reviewers This article was reviewed by Erik van Nimwegen, Teresa Przytycka (nominated by Claus Wilke), and Leonid Mirny. For the full reviews, please go to the Reviewer's Comments section. PMID:20459629

  14. PREFACE: Annual Conference on Functional Materials and Nanotechnologies - FM&NT 2011

    NASA Astrophysics Data System (ADS)

    Sternberg, Andris; Muzikante, Inta; Zicans, Janis

    2011-06-01

    Conference photograph ERAF logo International Organizing Committee Andris Sternberg (chairperson), Institute of Solid State Physics, University of Latvia, Latvia, MATERA Juras Banys, Vilnius University, Lithuania Gunnar Borstel, University of Osnabrück, Germany Niels E Christensen, University of Aarhus, Denmark Robert A Evarestov, St. Petersburg State University, Russia Claes-Goran Granqvist, Uppsala University, Sweden Dag Høvik, The Research Council of Norway, Norway, MATERA Marco Kirm, Institute of Physics, University of Tartu, Estonia Vladislav Lemanov, Ioffe Physical Technical Institute, Russia Witold Lojkowski, Institute of High Pressure Physics, Poland Ergo Nommiste, University of Tartu, Estonia Helmut Schober, Institut Laue-Langevin, France Sisko Sipilä, Finnish Funding Agency for Technology and Innovation, Finland, MATERA Ingólfur Torbjörnsson, Icelandic Centre for Research, Iceland, MATERA Marcel H Van de Voorde, University of Technology Delft, The Netherlands International Program Committee Inta Muzikante (chairperson), Institute of Solid State Physics, University of Latvia, Latvia, MATERA Liga Berzina-Cimdina, Institute of Biomaterials and Biomechanics, Riga Technical University, Latvia Janis Grabis, Institute of Inorganic Chemistry, Riga Technical University, Latvia Leonid V Maksimov, Vavilov State Optical Institute, Russia Linards Skuja, Institute of Solid State Physics, University of Latvia, Latvia Maris Springis, Institute of Solid State Physics, University of Latvia, Latvia Ilmars Zalite, Institute of Inorganic Chemistry, Riga Technical University, Latvia Janis Zicans, Institute of Polymers, Riga Technical University Local Committee: Liga Grinberga, Anatolijs Sarakovskis, Jurgis Grube, Raitis Siatkovskis, Maris Kundzins, Anna Muratova, Maris Springis, Aivars Vembris, Krisjanis Smits, Andris Fedotovs, Dmitrijs Bocarovs, Anastasija Jozepa, Andris Krumins.

  15. EDITORIAL: Focus on Advances in Surface and Interface Science 2009 FOCUS ON ADVANCES IN SURFACE AND INTERFACE SCIENCE 2009

    NASA Astrophysics Data System (ADS)

    Aeschlimann, Martin; Schneider, Wolf-Dieter

    2009-12-01

    to date look into the future. Focus on Contents Self-organized atomic nanowires of noble metals on Ge(001): atomic structure and electronic properties J Schäfer, S Meyer, C Blumenstein, K Roensch, R Claessen, S Mietke, M Klinke, T Podlich, R Matzdorf, A A Stekolnikov, S Sauer and F Bechstedt The role of polymorphism in organic thin films: oligoacenes investigated from first principles Claudia Ambrosch-Draxl, Dmitrii Nabok, Peter Puschnig and Christian Meisenbichler Searching for Si-based spintronics by first principles calculations Mahboubeh Hortamani, Leonid Sandratskii, Peter Kratzer and Ingrid Mertig Measuring spin polarization vectors in angle-resolved photoemission spectroscopy F Meier, J H Dil1 and J Osterwalder Hard x-ray photoelectron spectroscopy of oxide hybrid and heterostructures: a new method for the study of buried interfaces R Claessen, M Sing, M Paul, G Berner, A Wetscherek, A Müller and W Drube Single-atom contacts with a scanning tunnelling microscope J Kröger, N Néel, A Sperl, Y F Wang and R Berndt Electron-phonon coupling at surfaces and interfaces Ph Hofmann, I Yu Sklyadneva, E D L Rienks and E V Chulkov Adsorption of cobalt (II) octaethylporphyrin and 2H-octaethylporphyrin on Ag(111): new insight into the surface coordinative bond Yun Bai, Florian Buchner, Ina Kellner, Martin Schmid, Florian Vollnhals, Hans-Peter Steinrück, Hubertus Marbach and J Michael Gottfried Properties of metal-water interfaces studied from first principles Sebastian Schnur and Axel Groß Introducing artificial length scales to tailor magnetic properties J Fassbender, T Strache, M O Liedke, D Markó, S Wintz, K Lenz, A Keller, S Facsko, I Mönch and J McCord

  16. Limits on efficient computation in the physical world

    NASA Astrophysics Data System (ADS)

    Aaronson, Scott Joel

    More than a speculative technology, quantum computing seems to challenge our most basic intuitions about how the physical world should behave. In this thesis I show that, while some intuitions from classical computer science must be jettisoned in the light of modern physics, many others emerge nearly unscathed; and I use powerful tools from computational complexity theory to help determine which are which. In the first part of the thesis, I attack the common belief that quantum computing resembles classical exponential parallelism, by showing that quantum computers would face serious limitations on a wider range of problems than was previously known. In particular, any quantum algorithm that solves the collision problem---that of deciding whether a sequence of n integers is one-to-one or two-to-one---must query the sequence O (n1/5) times. This resolves a question that was open for years; previously no lower bound better than constant was known. A corollary is that there is no "black-box" quantum algorithm to break cryptographic hash functions or solve the Graph Isomorphism problem in polynomial time. I also show that relative to an oracle, quantum computers could not solve NP-complete problems in polynomial time, even with the help of nonuniform "quantum advice states"; and that any quantum algorithm needs O (2n/4/n) queries to find a local minimum of a black-box function on the n-dimensional hypercube. Surprisingly, the latter result also leads to new classical lower bounds for the local search problem. Finally, I give new lower bounds on quantum one-way communication complexity, and on the quantum query complexity of total Boolean functions and recursive Fourier sampling. The second part of the thesis studies the relationship of the quantum computing model to physical reality. I first examine the arguments of Leonid Levin, Stephen Wolfram, and others who believe quantum computing to be fundamentally impossible. I find their arguments unconvincing without a "Sure

  17. The Biological Big Bang model for the major transitions in evolution

    PubMed Central

    Koonin, Eugene V

    2007-01-01

    was reviewed by William Martin, Sergei Maslov, and Leonid Mirny. PMID:17708768

  18. Preface

    NASA Astrophysics Data System (ADS)

    Gurvits, L. I.; Frey, S.; Rawlings, S.

    than 30 contributed papers from that symposium have been published recently in Baltic Astronomy (2005, Vol. 14, No. 3). This book contains a set of invited review presentations given at the symposium. They cover a range of scientific topics in extragalactic and galactic radio astronomy studies as well as recent developments in radio astronomy techniques aimed at the next generation radio astronomy facilities. On behalf of the organisers and participants of the symposium, we express our gratitude to the sponsors of the event and this publication: the European Astronomical Society, Hungarian Academy of Sciences, Eötvös Loránd University, Konkoly Observatory, Eötvös Loránd Physical Society, Netherlands Foundation for Research in Astronomy (ASTRON), Joint Institute for VLBI in Europe, Hungarian Scientific Research Fund, EC FP5 Infrastructure Cooperation Network RadioNET and EC FP6 Integrated Infrastructure Initiative RadioNet. We are grateful to the members of the Scientific Organising Committee of the Symposium. Ken Kellermann made very useful remarks on several papers. Ellen Bouton and Pat Smiley helped to include in this book several photos from the AUI-NRAO archive. Mark Bentum designed the cover picture of the book, visual components for which were kindly supplied by W.A. Baan, M.F. Bietenholz, R. Boomsma, R. Braun, N. Bartel, M.A. Garrett, J.M. van der Hulst, H.R. Klockner, NASA/WMAP Science Team, T.A. Oosterloo, M.P. Rupen, R. Sancisi, B. Stappers, R.G. Strom, D.A. Thilker, and R.A.M. Walterbos. Most of all, we are grateful to all the authors of this book for their efforts in the increasingly old-fashioned art of writing papers for a real “paper” publication as opposed to putting powerpoint files on a web site. We do hope that their nice work will be appreciated by the readers. Leonid Gurvits, Dwingeloo, The Netherlands Sándor Frey, Budapest, Hungary Steve Rawlings, Oxford, UK

  19. Iridescent Glory of Nearby Helix Nebula

    NASA Image and Video Library

    2014-04-04

    This composite picture is a seamless blend of ultra-sharp NASA Hubble Space Telescope (HST) images combined with the wide view of the Mosaic Camera on the National Science Foundation's 0.9-meter telescope at Kitt Peak National Observatory, part of the National Optical Astronomy Observatory, near Tucson, Ariz. Astronomers at the Space Telescope Science Institute assembled these images into a mosaic. The mosaic was then blended with a wider photograph taken by the Mosaic Camera. The image shows a fine web of filamentary "bicycle-spoke" features embedded in the colorful red and blue gas ring, which is one of the nearest planetary nebulae to Earth. Because the nebula is nearby, it appears as nearly one-half the diameter of the full Moon. This required HST astronomers to take several exposures with the Advanced Camera for Surveys to capture most of the Helix. HST views were then blended with a wider photo taken by the Mosaic Camera. The portrait offers a dizzying look down what is actually a trillion-mile-long tunnel of glowing gases. The fluorescing tube is pointed nearly directly at Earth, so it looks more like a bubble than a cylinder. A forest of thousands of comet-like filaments, embedded along the inner rim of the nebula, points back toward the central star, which is a small, super-hot white dwarf. The tentacles formed when a hot "stellar wind" of gas plowed into colder shells of dust and gas ejected previously by the doomed star. Ground-based telescopes have seen these comet-like filaments for decades, but never before in such detail. The filaments may actually lie in a disk encircling the hot star, like a collar. The radiant tie-die colors correspond to glowing oxygen (blue) and hydrogen and nitrogen (red). Valuable Hubble observing time became available during the November 2002 Leonid meteor storm. To protect the spacecraft, including HST's precise mirror, controllers turned the aft end into the direction of the meteor stream for about half a day. Fortunately

  20. Observations of elevated Atlantic water heat fluxes at the boundary of the Arctic Basin.

    NASA Astrophysics Data System (ADS)

    Lincoln, Benjamin; Rippeth, Tom; Lenn, Yueng; Bacon, Sheldon

    2014-05-01

    diffusive fluxes. Dissipation rates were enhanced by up to 3 orders of magnitude at the boundaries of the Arctic basin with the highest rates North of Svalbard and decreasing ɛ anticlockwise around the basin with low ɛ in the Canada basin. Enhanced heat fluxes at the boundaries ranged from 10-100 Wm-2 north of Svalbard decreasing to 2-5 Wm-2 along the Laptev shelf slope and less than 0.5 Wm-2 along the East Siberian slope and Lomonosov ridge. In the Canada basin heat fluxes at the boundary were less than 0.2 Wm-2. --- Arctic Ocean Warming Contributes to Reduced Polar Ice Cap Igor V. Polyakov, Leonid A. Timokhov, Vladimir A. Alexeev, Sheldon Bacon, Igor A. Dmitrenko, Louis Fortier, et al. in Journal of Physical Oceanography (2010)

  1. Meteor Search by Spirit, Sol 668

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Annotated Meteor Search by Spirit, Sol 668

    The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture 'shooting stars,' or meteors, in the martian night sky. 'Meteoroids' are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long 'meteors' streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called 'meteorites.' The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in 'storms' or 'showers' at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These 'storms' happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets.

    The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on

  2. NRAO Scientists on Team Receiving International Astronautics Award

    NASA Astrophysics Data System (ADS)

    2005-10-01

    , a radio telescope bigger than the Earth." In addition to Fomalont and Romney, they are: Hisashi Hirabayashi, of the Institute of Space and Astronautical Science and Japan Aerospace Exploration Agency (ISAS/JAXA), Haruto Hirosawa (ISAS/JAXA), Peter Dewdney of Canada's Dominion Radio Astrophysical Observatory, Leonid Gurvits of the Joint Institute for VLBI in Europe (JIVE, The Netherlands), Makoto Inoue of the National Astronomical Observatory of Japan (NAOJ), David Jauncey of the Australia Telescope National Facility, Noriyuki Kawaguchi (NAOJ), Hideyuki Kobayashi (NAOJ), Kazuo Miyoshi (Mitsubishi Electric Corporation, Japan), Yasuhiro Murata (ISAS/JAXA), Takeshi Orii (NEC, Japan) Robert Preston of NASA's Jet Propulsion Laboratory (JPL), and Joel Smith (JPL). The International Academy of Astronautics was founded in August 1960 in Stockholm, Sweden, during the 11th International Astronautical Congress. The Academy aims to foster the development of astronautics for peaceful purposes; recognize individuals who have distinguished themselves in a related branch of science or technology; provide a program through which members may contribute to international endeavours; cooperation in the advancement of aerospace science. Previous recipients of the Laurels for Team Achievement Award are the Russian Mir Space Station Team (2001), the U.S. Space Shuttle Team (2002), the Solar and Heliospheric Observatory (SOHO) Team (2003), and the Hubble Space Telescope Team (2004). The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  3. Editorial: Focus on Atom Optics and its Applications

    NASA Astrophysics Data System (ADS)

    Schmidt-Kaler, F.; Pfau, T.; Schmelcher, P.; Schleich, W.

    2010-06-01

    Couvert, B Georgeot and D Guéry-Odelin Analysis of the entanglement between two individual atoms using global Raman rotations A Gaëtan, C Evellin, J Wolters, P Grangier, T Wilk and A Browaeys Spin polarization transfer in ground and metastable helium atom collisions D Vrinceanu and H R Sadeghpour A fiber Fabry-Perot cavity with high finesse D Hunger, T Steinmetz, Y Colombe, C Deutsch, T W Hänsch and J Reichel Atomic wave packets in amplitude-modulated vertical optical lattices A Alberti, G Ferrari, V V Ivanov, M L Chiofalo and G M Tino Atom interferometry with trapped Bose-Einstein condensates: impact of atom-atom interactions Julian Grond, Ulrich Hohenester, Igor Mazets and Jörg Schmiedmayer Storage of protonated water clusters in a biplanar multipole rf trap C Greve, M Kröner, S Trippel, P Woias, R Wester and M Weidemüller Single-atom detection on a chip: from realization to application A Stibor, H Bender, S Kühnhold, J Fortágh, C Zimmermann and A Günther Ultracold atoms as a target: absolute scattering cross-section measurements P Würtz, T Gericke, A Vogler and H Ott Entanglement-assisted atomic clock beyond the projection noise limit Anne Louchet-Chauvet, Jürgen Appel, Jelmer J Renema, Daniel Oblak, Niels Kjaergaard and Eugene S Polzik Towards the realization of atom trap trace analysis for 39Ar J Welte, F Ritterbusch, I Steinke, M Henrich, W Aeschbach-Hertig and M K Oberthaler Resonant superfluidity in an optical lattice I Titvinidze, M Snoek and W Hofstetter Interference of interacting matter waves Mattias Gustavsson, Elmar Haller, Manfred J Mark, Johann G Danzl, Russell Hart, Andrew J Daley and Hanns-Christoph Nägerl Magnetic trapping of NH molecules with 20 s lifetimes E Tsikata, W C Campbell, M T Hummon, H-I Lu and J M Doyle Imprinting patterns of neutral atoms in an optical lattice using magnetic resonance techniques Michal Karski, Leonid Förster, Jai-Min Choi, Andreas Steffen, Noomen Belmechri, Wolfgang Alt, Dieter Meschede and Artur Widera

  4. EDITORIAL: Message from the Editor Message from the Editor

    NASA Astrophysics Data System (ADS)

    Thomas, Paul

    2012-01-01

    Board Members, Guest Editors of special editions and those referees who were already listed in the last years. The following people have been selected: Marina Becoulet, CEA Cadarache, France Russell Doerner, University of California - San Diego, USA Emiliano Fable, Max-Planck-Institut fuer Plasmaphysik, Germany Akihide Fujisawa, Kyushi University, Japan Gerardo Giruzzi, CEA Cadarache, France Grigory Kagan, LANL, USA Morten Lennholm, CCFE, UK Akinobu Matsuyama, NIFS, Japan Peter Stangeby, University of Toronto, Canada Leonid Zakharov, PPPL, USA In addition, there is a group of several hundred referees who have helped us in the past year to maintain the high scientific standard of Nuclear Fusion. At the end of this issue we give the full list of all referees for 2011. Our thanks to them! Authors The winner of the 2011 Nuclear Fusion Award is H. Urano, for the paper 'Dimensionless parameter dependence of H-mode pedestal width using hydrogen and deuterium plasmas in JT-60U' (Nucl. Fusion 48 045008). The award was presented at the Plasma Conference 2011 (Joint meeting of 28th JSPF Annual Meeting, The 29th Symposium on Plasma Processing, and Division of Plasma Physics, 2011 Autumn Meeting of The Physical Society of Japan). This is the sixth year that the International Atomic Energy Agency (IAEA) has awarded an annual prize to honour exceptional work published in Nuclear Fusion. IOP Publishing has generously made a contribution of $2500 to the award. The Nuclear Fusion Electronic Archive The journal's electronic archive has been online since the beginning of the year. The archive has been a roaring success and has contributed to the nearly 300 000 downloads of journal papers in 2011. The archive can be accessed via http://iopscience.iop.org/0029-5515/page/Archive. It has direct links to 16 landmark papers, from authors such as Artsimovich and Mercier. The Nuclear Fusion office and IOP Publishing Just as the journal depends on the authors and referees, so its success is also

  5. Meteor Search by Spirit, Sol 668

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Annotated Meteor Search by Spirit, Sol 668

    The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture 'shooting stars,' or meteors, in the martian night sky. 'Meteoroids' are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long 'meteors' streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called 'meteorites.' The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in 'storms' or 'showers' at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These 'storms' happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets.

    The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on

  6. EDITORIAL: Focus on Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    2003-09-01

    The study of carbon nanotubes, since their discovery by Iijima in 1991, has become a full research field with significant contributions from all areas of research in solid-state and molecular physics and also from chemistry. This Focus Issue in New Journal of Physics reflects this active research, and presents articles detailing significant advances in the production of carbon nanotubes, the study of their mechanical and vibrational properties, electronic properties and optical transitions, and electrical and transport properties. Fundamental research, both theoretical and experimental, represents part of this progress. The potential applications of nanotubes will rely on the progress made in understanding their fundamental physics and chemistry, as presented here. We believe this Focus Issue will be an excellent guide for both beginners and experts in the research field of carbon nanotubes. It has been a great pleasure to edit the many excellent contributions from Europe, Japan, and the US, as well from a number of other countries, and to witness the remarkable effort put into the manuscripts by the contributors. We thank all the authors and referees involved in the process. In particular, we would like to express our gratitude to Alexander Bradshaw, who invited us put together this Focus Issue, and to Tim Smith and the New Journal of Physics staff for their extremely efficient handling of the manuscripts. Focus on Carbon Nanotubes Contents <;A article="1367-2630/5/1/117">Transport theory of carbon nanotube Y junctions R Egger, B Trauzettel, S Chen and F Siano The tubular conical helix of graphitic boron nitride F F Xu, Y Bando and D Golberg Formation pathways for single-wall carbon nanotube multiterminal junctions Inna Ponomareva, Leonid A Chernozatonskii, Antonis N Andriotis and Madhu Menon Synthesis and manipulation of carbon nanotubes J W Seo, E Couteau

  7. EDITORIAL: Focus on Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    2003-09-01

    The study of carbon nanotubes, since their discovery by Iijima in 1991, has become a full research field with significant contributions from all areas of research in solid-state and molecular physics and also from chemistry. This Focus Issue in New Journal of Physics reflects this active research, and presents articles detailing significant advances in the production of carbon nanotubes, the study of their mechanical and vibrational properties, electronic properties and optical transitions, and electrical and transport properties. Fundamental research, both theoretical and experimental, represents part of this progress. The potential applications of nanotubes will rely on the progress made in understanding their fundamental physics and chemistry, as presented here. We believe this Focus Issue will be an excellent guide for both beginners and experts in the research field of carbon nanotubes. It has been a great pleasure to edit the many excellent contributions from Europe, Japan, and the US, as well from a number of other countries, and to witness the remarkable effort put into the manuscripts by the contributors. We thank all the authors and referees involved in the process. In particular, we would like to express our gratitude to Alexander Bradshaw, who invited us put together this Focus Issue, and to Tim Smith and the New Journal of Physics staff for their extremely efficient handling of the manuscripts. Focus on Carbon Nanotubes Contents Transport theory of carbon nanotube Y junctions R Egger, B Trauzettel, S Chen and F Siano The tubular conical helix of graphitic boron nitride F F Xu, Y Bando and D Golberg Formation pathways for single-wall carbon nanotube multiterminal junctions Inna Ponomareva, Leonid A Chernozatonskii, Antonis N Andriotis and Madhu Menon Synthesis and manipulation of carbon nanotubes J W Seo, E Couteau, P Umek, K Hernadi, P Marcoux, B Lukic, Cs Mikó, M Milas, R Gaál and L Forró Transitional behaviour in the transformation from active end

  8. PREFACE: Semiconducting oxides Semiconducting oxides

    NASA Astrophysics Data System (ADS)

    Catlow, Richard; Walsh, Aron

    2011-08-01

    their help in producing this special section. We hope that it conveys some of the excitement and significance of the field. Semiconducting oxides contents Chemical bonding in copper-based transparent conducting oxides: CuMO2 (M = In, Ga, Sc) K G Godinho, B J Morgan, J P Allen, D O Scanlon and G W Watson Electrical properties of (Ba, Sr)TiO3 thin films with Pt and ITO electrodes: dielectric and rectifying behaviourShunyi Li, Cosmina Ghinea, Thorsten J M Bayer, Markus Motzko, Robert Schafranek and Andreas Klein Orientation dependent ionization potential of In2O3: a natural source for inhomogeneous barrier formation at electrode interfaces in organic electronicsMareike V Hohmann, Péter Ágoston, André Wachau, Thorsten J M Bayer, Joachim Brötz, Karsten Albe and Andreas Klein Cathodoluminescence studies of electron irradiation effects in n-type ZnOCasey Schwarz, Yuqing Lin, Max Shathkin, Elena Flitsiyan and Leonid Chernyak Resonant Raman scattering in ZnO:Mn and ZnO:Mn:Al thin films grown by RF sputteringM F Cerqueira, M I Vasilevskiy, F Oliveira, A G Rolo, T Viseu, J Ayres de Campos, E Alves and R Correia Structure and electrical properties of nanoparticulate tungsten oxide prepared by microwave plasma synthesisM Sagmeister, M Postl, U Brossmann, E J W List, A Klug, I Letofsky-Papst, D V Szabó and R Würschum Charge compensation in trivalent cation doped bulk rutile TiO2Anna Iwaszuk and Michael Nolan Deep level transient spectroscopy studies of n-type ZnO single crystals grown by different techniquesL Scheffler, Vl Kolkovsky, E V Lavrov and J Weber Microstructural and conductivity changes induced by annealing of ZnO:B thin films deposited by chemical vapour depositionC David, T Girardeau, F Paumier, D Eyidi, B Lacroix, N Papathanasiou, B P Tinkham, P Guérin and M Marteau Multi-component transparent conducting oxides: progress in materials modellingAron Walsh, Juarez L F Da Silva and Su-Huai Wei Thickness dependence of the strain, band gap and transport properties of

  9. Radio Telescopes Will Add to Cassini-Huygens Discoveries

    NASA Astrophysics Data System (ADS)

    2004-12-01

    accuracy. They expect to measure the probe's position within two-thirds of a mile (1 kilometer) at a distance of nearly 750 million miles. "That's like being able to sit in your back yard and watch the ball in a ping-pong game being played on the Moon," said Leonid Gurvits of JIVE. Both the JPL and JIVE teams will record the data collected by the radio telescopes and process it later. In the case of the Doppler measurements, some real-time information may be available, depending on the strength of the signal, but the scientists on this team also plan to do their detailed analysis on recorded data. The JPL team is utilizing special instrumentation from the Deep Space Network called Radio Science Receivers. One will be loaned to the GBT and another to the Parkes radio observatory. "This is the same instrument that allowed us to support the challenging communications during the landing of the Spirit and Opportunity Mars rovers as well as the Cassini Saturn Orbit Insertion when the received radio signal was very weak," said Sami Asmar, the JPL scientist responsible for the data recording. When the Galileo spacecraft's probe entered Jupiter's atmosphere in 1995, a JPL team used the NSF's Very Large Array (VLA) radio telescope in New Mexico to directly track the probe's signal. Adding the data from the VLA to that experiment dramatically improved the accuracy of the wind-speed measurements. "The Galileo probe gave us a surprise. Contrary to some predictions, we learned that Jupiter's winds got stronger as we went deeper into its atmosphere. That tells us that those deeper winds are not driven entirely by sunlight, but also by heat coming up from the planet's core. If we get lucky at Titan, we'll get surprises there, too," said Robert Preston, another JPL scientist. The Huygens probe is a spacecraft built by the European Space Agency (ESA). In addition to the NRAO telescopes, the JPL Doppler Wind Experiment will use the Australia Telescope National Facility and other radio

  10. EDITORIAL: From reciprocal space to real space in surface science From reciprocal space to real space in surface science

    NASA Astrophysics Data System (ADS)

    Bartels, Ludwig; Ernst, Karl-Heinz

    2012-09-01

    Triest.let's finish—aus basta Some move atoms around to hear how they sound.Karl-Heinz Rieder, Erice, 6 April 1998 From reciprocal space to real space in surface science contents From reciprocal space to real space in surface scienceLudwig Bartels and Karl-Heinz Ernst Karl-Heinz Reider: the quiet pioneerGiorgio Benedek Scattering of CO and N2 molecules by a graphite surfaceJunepyo Oh, Takahiro Kondo, Keitaro Arakawa, Yoshihiko Saito, Junji Nakamura, W W Hayes and J R Manson Helium, neon and argon diffraction from Ru(0001)M Minniti, C Díaz, J L Fernández Cuñado, A Politano, D Maccariello, F Martín, D Farías and R Miranda Enhanced charge transfer in a monolayer of the organic charge transfer complex TTF-TNAP on Au(111)T R Umbach, I Fernandez-Torrente, J N Ladenthin, J I Pascual and K J Franke Extended pattern recognition scheme for self-learning kinetic Monte Carlo simulationsSyed Islamuddin Shah, Giridhar Nandipati, Abdelkader Kara and Talat S Rahman Acetylene on Cu(111): imaging a molecular surface arrangement with a constantly rearranging tipYeming Zhu, Jonathan Wyrick, Kamelia D Cohen, Katie Marie Magnone, Connor Holzke, Daniel Salib, Quan Ma, Dezheng Sun and Ludwig Bartels Coulomb attraction during the carpet growth mode of NaClFriederike Matthaei, Sarah Heidorn, Konrad Boom, Cord Bertram, Ali Safiei, Jörg Henzl and Karina Morgenstern Molecular self-assembly on an insulating surface: interplay between substrate templating and intermolecular interactionsMarkus Kittelmann, Philipp Rahe and Angelika Kühnle Vertical manipulation of native adatoms on the InAs(111)A surfaceJ Yang, C Nacci, J Martínez-Blanco, K Kanisawa and S Fölsch Charge transfer between isomer domains on n+-doped Si(111)-2 × 1: energetic stabilizationR M Feenstra, G Bussetti, B Bonanni, A Violante, C Goletti, P Chiaradia, M G Betti and C Mariani Probing the properties of metal-oxide interfaces: silica films on Mo and Ru supportsLeonid Lichtenstein, Markus Heyde, Stefan Ulrich, Niklas Nilius

  11. Obituary: Thomas C. Van Flandern (1940-2009)

    NASA Astrophysics Data System (ADS)

    Dunham, David; Slabinski, Victor

    2011-12-01

    planetary formation. The Bulletin claimed mainstream scientists preferred making ad hoc corrections to the theories rather than acknowledge fundamental difficulties that might jeopardize their funding. Tom Van Flandern's advocacy of an artificial origin for the "face on Mars," especially after higher-resolution images were taken in 2001, antagonized many. His questioning of the speed of gravity, first published in a 1998 paper in Physics Letters A, provoked additional attacks from relativists. He showed the same persistence with these controversies that had enabled him to solve complex programming and celestial mechanics problems. Tom Van Flandern did not reject General Relativity as some have asserted, but rather rejected its geometrical interpretation. He said: "General relativity has a geometric and a field interpretation. If angular momentum conservation is invoked in the geometric interpretation to explain experiments, the causality principle is violated. The field interpretation avoids this problem by allowing faster-than-light propagation in forward time." For more, see http://www.metaresearch.org/cosmology/gravity/speed_limit.asp. Tom Van Flandern strongly attacked some alternative theories, such as Velikovsky's ideas of recent planetary close approaches, turning one of Velikovsky's supporters, C. L. Ellenberger, into a strong critic. If not for these antagonisms, the "mainstream" part of Tom Van Flandern's work in later years might be better acknowledged, including his "Eclipse Edge" company that organized expeditions to several solar eclipses, and his work with E. Lyytinen on the passage of Earth through cometary debris trails. Their prediction was closest to the observed time of the Leonid storm maximum of November 2001. Tom Van Flandern held memberships in the International Astronomical Union, the American Astronomical Society (and in its Divisions on Dynamical Astronomy and Planetary Sciences), and several other scientific organizations. He received second

  12. PREFACE: 13th International Conference on Liquid and Amorphous Metals

    NASA Astrophysics Data System (ADS)

    Popel, Pjotr; Gelchinskii, Boris; Sidorov, Valeriy; Son, Leonid; Sabirzjanov, Alexandre

    2007-06-01

    helped us to manage it in the best way, namely to J Dupuy, M Silbert, F Sommer, W C Pilgrim, W Freyland, K Lu, J Brmejo and F Hensel.

  13. We dedicate the LAM13 conference to the 80-year jubilee of Professor Nikolay Vatolin who is the leader of Russian investigations in the field of liquid and amorphous metals and who managed twelve(!) similar conferences in our country. One of us (PP) commemorates his father, Professor Stanislav Popel, who was a known specialist in high temperature capillarity and left us half a year before the event. Pjotr Popel, Boris Gelchinskii, Valeriy Sidorov, Leonid Son, Alexandre Sabirzjanov Ekaterinburg, January 14 2008

  14. Granitoid magmatism of Alarmaut granite-metamorphic dome, West Chukotka, NE Russia

    NASA Astrophysics Data System (ADS)

    Luchitskaya, M. V.; Sokolov, S. D.; Bondarenko, G. E.; Katkov, S. M.

    2009-04-01

    .L. Phanerozoic granite-metamorphic domes at Russian North-East. Paper 2. Magmatism, metamorphism and migmatization in Late Mesozoic domes // Pacific geology. 1996. V. 15. № 1. P. 84-93. (in Russian) 13. Bering Strait Geologic Field Party, Koolen metamorphic complex, NE Russia: implications for the tectonic evolution of the Bering Strait region // Tectonics, vol. 16, no. 5, p. 713-729 14. Bondarenko G.E., Luchitskaya M.V. Mesozoic tectonic evolution of Alarmaut rise // Byul. MOIP. Otd. Geol. V. 78. Is. 3. P. 25-38. (in Russian) 15. Katkov S.M., Strikland A., Miller E.L. Age of granite batholiths in the Anyui-Chukotka Foldbelt // Doklady. Earth Sciences. 2007. Vol. 414. № 4. P. 515-518. 16. Amato J.M., Wright J.E. Potassic mafic magtism in the Kigluaik gneiss dome, northern Alaska: a geochemical study of arc magmatism in an extensional tectonic setting // J. Geophys. Res. 1997. Vol.102. N B4. P.8065-8084 17. Tikhomirov P.L., Luchitskaya M.V., Kravchenko-Berezhnoy I.R. Comparison of Cretaceous granitoids of the Chaun tectonic zone to those of the Taigonos Peninsula, NE Asia: rock chemistry, composition of rock forming minerals, and conditions of formation // Stephan Mueller series. Geology and Tectonic Origins of Northeast Russia: A Tribute to Leonid Parfenov (in press) 28. Velikoslavinsky S.D. Geochemical typification of acid magmatic rocks of leading geodynamic settings // Petrology. 2003. V. 11. № 4. P.363-380. (in Russian) 19. Pearce J.A. Sources and settings of granitic rocks // Episodes. 1996. V. 19. N. 4. P. 120-125

  15. Catching a Falling Star

    NASA Astrophysics Data System (ADS)

    2004-07-01

    . Comets are another important source of meteoroids and perhaps the most spectacular. After many visits near the Sun, a comet "dirty-snowball" nucleus of ice and dust decays and fragments, leaving a trail of meteoroids along its orbit. Some "meteoroid streams" cross the earth's orbit and when our planet passes through them, some of these particles will enter the atmosphere. The outcome is a meteor shower - the most famous being the "Perseids" in the month of August [2] and the "Leonids" in November. Thus, although meteors are referred to as "shooting" or "falling stars" in many languages, they are of a very different nature. More information The research presented in this paper is published in the journal Meteoritics and Planetary Science, Vol. 39, Nr. 4, p. 1, 2004 ("Spectroscopic anatomy of a meteor trail cross section with the ESO Very Large Telescope", by P. Jenniskens et al.). Notes [1] The team is composed of Peter Jenniskens (SETI Institute, USA), Emmanuël Jehin (ESO), Remi Cabanac (Pontificia Universidad Catolica de Chile), Christophe Laux (Ecole Centrale de Paris, France), and Iain Boyd (University of Michigan, USA). [2] The maximum of the Perseids is expected on August 12 after sunset and should be easily seen.

  16. HWHAP_Ep5_Astronaut-Training

    NASA Image and Video Library

    2017-08-04

    BREZHNEV. [ LAUGHTER ] AND THAT WAS IT. AND I-- YOU KNOW, HERE I AM QUITE A FEW DECADES LATER, AND HAVEN’T DONE ANYTHING STUPID TO GET A NEW ONE. [ LAUGHTER ] >> BREZHNEV AFTER THE SOVIET LEADER? >> LEONID BREZHNEV, YEAH. >> OKAY, AND I GUESS EVERYONE CALLED EACH OTHER KOMRADE AS LIKE A-- >> THAT’S-- DURING SOVIET TIMES THAT WAS HOW EVERYBODY ADDRESSED THEMSELVES. >> HOW-- OKAY, I GET THE REFERENCE NOW. SO JUST AS A LITTLE BIT OF BACKGROUND, BUT-- YOU’RE NAVY AND MARINES, IS THAT CORRECT? >> I AM A-- THE OVERALL ARCHING IS NAVAL AVIATOR, WHICH INCLUDES THE NAVY AND THE MARINE CORPS AVIATORS. WE WEAR THE SAME WINGS ON OUR FL-- WE EARN THE SAME WINGS IN FLIGHT SCHOOL AND WEAR THE SAME WINGS ON OUR FLIGHT SUITS. >> OKAY, SO WHEN YOU TALK ABOUT LAUNCHING OFF OF CARRIERS AND THE MARINES-- >> RIGHT, THAT’S PART OF OUR OVERALL NAVAL AVIATOR TRAINING. SO I WAS TRAINED TO LAUNCH OFF AN AIRCRAFT CARRIER-- LAUNCHED A T-2, A-4, AND AN F-18. BUT THEN AS A MARINE WE DEPLOY EXPEDITIONARITY-- IS THAT EVEN A WORD? [ LAUGHTER ] >> WE’LL MAKE IT A WORD. >> WE’RE EXPEDITION BASED, BUT WE’LL LAUNCH AND ESTABLISH FORWARD BASES AND FLY OUT OF THERE, SO JUST FLYING OFF THE AIRCRAFT CARRIER. >> OKAY, OKAY. NOW, YOU’RE GOING TO BE LAUNCHING SOON-- OR, DEPENDING ON WHEN THIS PODCAST IS RELEASED, YOU’RE IN SPACE RIGHT NOW-- BUT THIS IS NOT YOUR FIRST RODEO, RIGHT? YOU’VE BEEN IN SPACE BEFORE. YOU LAUNCHED IN 2009 ON STS-129 ABOARD ATLANTIS. HOW WAS THAT? >> STS-129 WAS REALLY NEAT. I HAD, FORTUNATELY, A REALLY GREAT CREW. WE HAD TWO MARINE TEST PILOTS, WE HAD TWO NAVY TEST PILOTS, AND WE HAD TWO SMART GUYS. [ LAUGHTER ] OUR SMART GUYS-- YOU KNOW, LELAND MELVIN, HERE HE IS, HE HAD BEEN DRAFTED INTO THE NFL, PLAYING FOOTBALL, BUT HAD A CAREER-ENDING INJURY, BUT HE FINISHED HIS EDUCATION, WENT BACK AND GOT HIS MASTER’S, BECAME A NASA ENGINEER, AND THEN BECAME AN ASTRONAUT. >> AWESOME. >> YEAH, AND THEN BECAUSE WE HAD THE TWO MARINES, YOU NEED TO, YOU KNOW, RAISE THE AVERAGE IQ ON