Evolution of two periodic meteoroid streams: The Perseids and Leonids

NASA Astrophysics Data System (ADS)

Brown, Peter Gordon

Observations and modelling of the Perseid and Leonid meteoroid streams are presented and discussed. The Perseid stream is found to consist of three components: a weak background component, a core component and an outburst component. The particle distribution is identical for the outburst and core populations. Original visual accounts of the Leonid stream from 1832-1997 are analyzed to determine the time and magnitude of the peak for 32 Leonid returns in this interval. Leonid storms are shown to follow a gaussian flux profile, to occur after the perihelion passage of 55P/Tempel-Tuttle and to have a width/particle density relationship consistent with IRAS cometary trail results. Variations in the width of the 1966 Leonid storm as a function of meteoroid mass are as expected based on the Whipple ejection velocity formalism. Four major models of cometary meteoroid ejection are developed and used to simulate plausible starting conditions for the formation of the Perseid and Leonid streams. Initial ejection velocities strongly influence Perseid stream development for the first five revolutions after ejection, at which point planetary perturbations and radiation effects become important for further development. The minimum distance between the osculating orbit of 109P/Swift-Tuttle and the Earth was found to be the principle determinant of any subsequent delivery of meteoroids to Earth. Systematic shifts in the location of the outburst component of the Perseids were shown to be due to the changing age of the primary meteoroid population making up the outbursts. The outburst component is due to distant, direct planetary perturbations from Jupiter and Saturn shifting nodal points inward relative to the comet. The age of the core population of the stream is found to be (25 +/- 10) × 10 3 years while the total age of the stream is in excess of 10 5 years. The primary sinks for the stream are hyperbolic ejection and attainment of sungrazing states due to perturbations from

Reaching 1 m deep on Mars: the Icebreaker drill.

PubMed

Zacny, K; Paulsen, G; McKay, C P; Glass, B; Davé, A; Davila, A F; Marinova, M; Mellerowicz, B; Heldmann, J; Stoker, C; Cabrol, N; Hedlund, M; Craft, J

2013-12-01

The future exploration of Mars will require access to the subsurface, along with acquisition of samples for scientific analysis and ground-truthing of water ice and mineral reserves for in situ resource utilization. The Icebreaker drill is an integral part of the Icebreaker mission concept to search for life in ice-rich regions on Mars. Since the mission targets Mars Special Regions as defined by the Committee on Space Research (COSPAR), the drill has to meet the appropriate cleanliness standards as requested by NASA's Planetary Protection Office. In addition, the Icebreaker mission carries life-detection instruments; and in turn, the drill and sample delivery system have to meet stringent contamination requirements to prevent false positives. This paper reports on the development and testing of the Icebreaker drill, a 1 m class rotary-percussive drill and triple redundant sample delivery system. The drill acquires subsurface samples in short, approximately 10 cm bites, which makes the sampling system robust and prevents thawing and phase changes in the target materials. Autonomous drilling, sample acquisition, and sample transfer have been successfully demonstrated in Mars analog environments in the Arctic and the Antarctic Dry Valleys, as well as in a Mars environmental chamber. In all environments, the drill has been shown to perform at the "1-1-100-100" level; that is, it drilled to 1 m depth in approximately 1 hour with less than 100 N weight on bit and approximately 100 W of power. The drilled substrate varied and included pure ice, ice-rich regolith with and without rocks and with and without 2% perchlorate, and whole rocks. The drill is currently at a Technology Readiness Level (TRL) of 5. The next-generation Icebreaker drill weighs 10 kg, which is representative of the flightlike model at TRL 5/6.

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

DTIC Science & Technology

2014-02-11

Efforts to Identify Arctic Requirements Are Ongoing, but More Communication about Agency Planning Efforts Would Be Beneficial, GAO-10- 870, September...icebreakers also have substantial command, control, and communications capabilities. The flexibility and mobility of polar icebreakers would assist...Fisheries enforcement in Bering Sea to prevent foreign fishing in U.S. waters and overfishing —Capability to conduct search and rescue in Beaufort Sea

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

DTIC Science & Technology

2013-07-24

but More Communication about Agency Planning Efforts Would Be Beneficial, GAO-10- 870, September 2010, p. 53. Coast Guard Polar Icebreaker...and helicopters. Polar icebreakers also have substantial command, control, and communications capabilities. The flexibility and mobility of polar...Coast Guard —Fisheries enforcement in Bering Sea to prevent foreign fishing in U.S. waters and overfishing —Capability to conduct search and rescue in

A New Peak of Leonids observed by Radio Technics

NASA Astrophysics Data System (ADS)

Suzuki, K.; Maegawa, K.; Minagawa, Y.

Radio meteor observations with amateur ham radio wave have been carried out in Japan since August, 1996, by using forward-scattered meteor echoes of VHF radio waves (53.75MHz, 50W, CW) transmitted in Sabae, Fukui prefecture. A strong activity of Leonids was observed between 22h and 01h on November 16/17 (UT), 1996. The hourly rate of long duration echoes reached over 50 times larger than in non-shower period and 1.2 to 1.5 times larger than that at the normal maximum of Leonids, respectively. This enhanced activity occurred at a solar longitude (SL) of 234.95 plus or minus 0.05 degrees (2000.0 eq.), and is probably different from normal peak of Leonids at 235.45 plus or minus 0.05 degrees(2000.0 eq.) observed in 1990's. A corresponding peak in 1995 was also reported by visual meteor observation by many observers in Japan. The ascending node of Comet Tempel-Tuttle in 1966 was at 235.11 degrees in SL, and is closer to the new peak than the normal one (at 235.45 degrees in SL).

Building Community in the Classroom through Ice-Breakers and Parting Ways

ERIC Educational Resources Information Center

Eggleston, Tami; Smith, Gabie

2004-01-01

Many instructors are concerned with creating a community in the classroom. Although there are numerous published "ice-breakers," many of these techniques are not specific to psychology courses or have been used so much that the students see them as redundant and cliche. Icebreakers are better if they have relevance to a specific class, are…

Translations on USSR Science and Technology Biomedical and Behavioral Sciences No. 47.

DTIC Science & Technology

1978-10-27

problem is allowed to be simplified,, then the basic contents of the ergonomic section may be castrated ; if it is complicated, then the document will be...demands of agriculture. The rise of livestock farming does not mean only an increase in cattle stock, but also an increase in the productivity of... cattle and poultry. Leonid Il’yich Brezhnev stressed atthe July Plenum: "All that we want to have rom the animal husbandry is more meat, milk, and other

The 2002 Leonids Using 28 MHz Ham-band Radio Observations (HRO) over = Japan

NASA Astrophysics Data System (ADS)

Usui, T.; Ogawa, H.; Hashimoto, T.; Ohnishi, K.; Yaguchi, N.; = Maegawa, K.

2002-12-01

The 2002 Leonids were expected to present a spectacular appearance = over Europe and America. No spectacular appearance was expected in Japan. On = the evening of November 17 (UT), however, the 1965 dust trail was predicted = to approach the Earth closely. Therefore, Japanese observers tried to = detect this trail using 28 MHz radio. This is because 28 MHz observations can = detect fainter meteor echoes than 53 MHz observations which are prevalent in Japan. = This study shows the observing method and results of 28 MHz observations of the = 2002 Leonids. We found that the Leonids were detectable for longer at 28 MHz than at = 53.75 MHz. This indicates that the distribution of fainter (smaller) meteors is = wider than that of larger ones.

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

DTIC Science & Technology

2016-11-10

time between the end of Polar Star’s current intended service life and the entry into service of one or more new heavy polar icebreakers. There are...at least two options for bridging this time period: One would be to further extend the service life of Polar Star and/or repair and extend the...service life of Polar Sea. The other would be to charter (i.e., lease) one or more other icebreakers (perhaps foreign- owned ones), if such ships are

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.

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.

Open-Water Resistance and Seakeeping Characteristics of Ships with Icebreaking Bows

DTIC Science & Technology

1991-05-13

of a Knuckled Forefoot on a Typical Icebreaker ...... ................... . 19 3-2. Lines Plan, T-AGS OCEAN (ICE) . * * .... . 23 3-3. Curve of...the ice. As the stem strikes the ice, initial failure of the ice occurs by simple crushing. Then the raked stem of the icebreaker rides up onto the ice...bossings, skegs, rudders, 18 and special stem forefoot shapes were not included in the shapes tested. To ensure that the parent and its variants

Activity of the 1998 Leonid Shower From the Video Records

NASA Technical Reports Server (NTRS)

Jenniskens, Peter

1999-01-01

Video observations of the Leonid shower aboard two aircraft in the 1998 Leonid multi-instrument aircraft campaign and from ground locations in China are presented. Observing at altitude proved particularly effective, with four times higher rates due to low extinction and low angular velocity at the horizon. The rates, derived from a total of 2500 Leonid meteors, trace at least two distinct dust components. One dominated the night of 1998 November 16/17. This two-day wide component was rich in bright meteors with r = N (m + 1)/N (m) approximately equal 1.5 (s = 1.4) and peaked at an influx of 3.1 +/- 0.4 x 10(exp -12) /sq m.s (for particles of mass < 7 x 10(exp -5) g) at solar longitude lambda(sub 0) approximately equal 234.52 (Eq. J2000). The other more narrow component peaked on 1998 November 17/18 at lambda(sub 0) = 235.31 +/- 0.01. Rates were elevated above the broad component between lambda(sub 0) = 235.15 and 235.40, symmetric around the current node of the parent comet 55P/Tempel-Tuttle, peaking at 5.1 +/- 0.2 x 10(exp -12) /sq m.s. The population index was higher, r = 1.8 +/- 0.1 (s = 1.7), but not as high as in past Leonid storms (r = 3.0). The flux profile of this component has an unusual asymmetric shape, which implies a blend of contributions from at least two different but relatively recent epochs of ejection. The variation of r across the profile might be due to mass-dependent ejection velocities of the narrowest component. High rates of faint meteors occurred only in an isolated five-minute interval at lambda(sub 0) = 235.198, which is likely the result of a single meteoroid breakup in space.

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.

Leonid predictions for the period 2001-2100

NASA Astrophysics Data System (ADS)

Maslov, Mikhail

2007-02-01

This article provides a set of summaries of what to expect from the Leonid meteor shower for each year of the period 2001-2100. Each summary contains the moments of maximum/maxima, their expected intensity and some comments about average meteor brightness during them. Special attention was paid to background (traditional) maxima, which are characterized with their expected times and intensities.

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.

Successful Hybrid Approach to Visual and Video Observations of the 1999 Leonid Storm

NASA Technical Reports Server (NTRS)

Jenniskens, Peter; Crawford, Chris; Butow, Steve; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

A new hybrid technique of visual and video meteor observations is described. The method proved particularly effective for airborne observations of meteor shower activity. Results from the 1999 Leonid Multi-Instrument Aircraft Campaign are presented, and the profile shape of the 1999 Leonid storm is discussed in relation to meteor shower models. We find that the storm is best described with a Lorentz profile. Application to past meteor outbursts shows that the cui,rent multi-trailet model of a dust trail is slightly shifted and we crossed deeper into the 1899 epoch trallet than expected.

Designing a Maintainable and Sustainable Coast Guard Icebreaker for Arctic and Antarctic Operations

DTIC Science & Technology

2014-03-21

03-2014 Technical June 2013-August 2013 Designing a Maintainable and Sustainable Coast Guard Icebreaker for Arctic and Antarctic Operations...of Engineering Designing a Maintainable and Sustainable Coast Guard Icebreaker for Arctic and Antarctic Operations Abstract The U.S. Coast Guard is...Pollution (MARPOL) of which Annex V prohibits the discharge of solid waste other than food refuge less than 25mm in diameter into the Antarctic Region [6

Atmospheric behavior and extreme beginning heights of the 13 brightest photographic Leonids from the ground-based expedition to China

NASA Astrophysics Data System (ADS)

Spurný, Pavel; Betlem, Hans; van't Leven, Jaap; Jenniskens, Peter

2000-03-01

Precise atmospheric trajectories including dynamic and photometric data on the 13 of the brightest Leonid fireballs have been determined from the double station photographic observations of Leonids during the ground-based expedition to China in November 1998. The expedition was organized as a collaboration between the Dutch and Chinese Academy of Sciences and was supported by the Leonid MAC program (Jenniskens and Butow, 1999). All data presented here were taken at Xinglong Observatory and at a remote station Lin Ting Kou near Beijing on the night of November 16/17. At Xinglong station photographic cameras were accompanied with an all-sky TV camera equipped with an image intensifier and 15 mm fish-eye objective in order to obtain precise timings for all observed meteors up to magnitude +2. While beginning heights of photographed meteors are all lower than 130 km, those observed by the all-sky TV system are at about 160 km and for three brightest events even above 180 km. Such high beginnings for meteors have never before been observed. We obtained also a precise dynamic single-body solution for the Leonid meteor 98003 including the ablation coefficient, which is an important material and structural quantity (0.16 s2km-2). From this, and from known photometry, we derived a density of this meteoroid of 0.7 g/cm3. Also all PE coefficients indicate that these Leonids belonged to the fireball group IIIB which is typical for the most fragile and weak interplanetary bodies. From a photometric study of the meteor lightcurves we found two typical shapes of light curves for these Leonids.

Using Appreciative Intelligence for Ice-Breaking: A New Design

ERIC Educational Resources Information Center

Verma, Neena; Pathak, Anil Anand

2011-01-01

Purpose: The purpose of this paper is to highlight the importance of applying appreciative intelligence and appreciative inquiry concepts to design a possibly new model of ice-breaking, which is strengths-based and very often used in any training in general and team building training in particular. Design/methodology/approach: The design has…

The Icebreaker Mission to Search for Life on Mars

NASA Technical Reports Server (NTRS)

Stoker, C.; Mckay, C.; Brinckerhoff, W.; Davila, A.; Parro, V.; Quinn, R.

2015-01-01

The search for evidence of life on Mars is the ultimate motivation for its scientific exploration. The results from the Phoenix mission indicate that the high N. latitude ice-rich regolith at low elevations is likely to be a recently habitable place on Mars [Stoker et al., 2010]. The near-surface ice likely provided adequate water activity during periods of high obliquity, 3 to 10 Myr ago. Carbon dioxide and nitrogen are present in the atmosphere, and nitrates may be present in the soil. Together with iron in basaltic rocks and perchlorate in the soil they provide carbon and energy sources, and oxidative power to drive metabolism. Furthermore, the presence of organics is possible, as thermally reactive perchlorate would have prevented their detection by Viking and Phoenix. The Mars Icebreaker Life mission [McKay et al., 2013] focuses on the following science goals: (1) Search for biomolecular evidence of life; (2) Search for organic matter from either exogeneous or endogeneous sources using methods that are not effected by the presence of perchlorate; (3) Characterize oxidative species that produced reactivity of soils seen by Viking; and 4) Assess the habitability of the ice bearing soils. The Icebreaker Life payload (Figure 1) includes a 1-m rotary percussive drill that brings cuttings samples to the surface where they are delivered to three instruments (Fig. 1), the Signs of Life Detector (SOLID) [Parro et al., 2011] for biomolecular analysis, Laser Desorption Mass Spectrometer (LDMS) [??? 2015]) for broad spectrum organic analysis, and Wet Chemistry Laboratory (WCL) [Hecht et al., 2009] for detecting soluble species of nutrients and reactive oxidants. The Icebreaker payload fits on the Phoenix spacecraft and can land at the well-characterized Phoe-nix landing site in 2020 in a Discovery-class mission.

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.

Kick-Start Your Class: Academic Icebreakers to Engage Students

ERIC Educational Resources Information Center

Johnson, LouAnne

2012-01-01

LouAnne Johnson's newest book is a collection of fun and simple educational icebreaker activities that get students excited and engaged from the very first minute of class. These activities are great to use with students at all levels, and many of the activities include variations and modifications for different groups. Research has shown that the…

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.

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.

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.

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.

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

DTIC Science & Technology

2013-04-25

Accountability Office, Coast Guard[:]Efforts to Identify Arctic Requirements Are Ongoing, but More Communication about Agency Planning Efforts Would...control, and communications capabilities. The flexibility and mobility of polar icebreakers would assist the Coast Guard in closing future mission...Sea to prevent foreign fishing in U.S. waters and overfishing —Capability to conduct search and rescue in Beaufort Sea for cruise line and natural

The Icebreaker Life Mission to Mars: A Search for Biomolecular Evidence for Life

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.; Stoker, Carol R.; Glass, Brian J.; Dave, Arwen I.; Davila, Alfonso F.; Heldmann, Jennifer L.; Marinova, Margarita M.; Fairen, Alberto G; Quinn, Richard C; Zacny, Kris A.;

The Icebreaker Life Mission to Mars: a search for biomolecular evidence for life.

PubMed

McKay, Christopher P; Stoker, Carol R; Glass, Brian J; Davé, Arwen I; Davila, Alfonso F; Heldmann, Jennifer L; Marinova, Margarita M; Fairen, Alberto G; Quinn, Richard C; Zacny, Kris A; Paulsen, Gale; Smith, Peter H; Parro, Victor; Andersen, Dale T; Hecht, Michael H; Lacelle, Denis; Pollard, Wayne H

2013-04-01

The search for evidence of life on Mars is the primary motivation for the exploration of that planet. The results from previous missions, and the Phoenix mission in particular, indicate that the ice-cemented ground in the north polar plains is likely to be the most recently habitable place that is currently known on Mars. The near-surface ice likely provided adequate water activity during periods of high obliquity, ≈ 5 Myr ago. Carbon dioxide and nitrogen are present in the atmosphere, and nitrates may be present in the soil. Perchlorate in the soil together with iron in basaltic rock provides a possible energy source for life. Furthermore, the presence of organics must once again be considered, as the results of the Viking GCMS are now suspect given the discovery of the thermally reactive perchlorate. Ground ice may provide a way to preserve organic molecules for extended periods of time, especially organic biomarkers. The Mars Icebreaker Life mission focuses on the following science goals: (1) Search for specific biomolecules that would be conclusive evidence of life. (2) Perform a general search for organic molecules in the ground ice. (3) Determine the processes of ground ice formation and the role of liquid water. (4) Understand the mechanical properties of the martian polar ice-cemented soil. (5) Assess the recent habitability of the environment with respect to required elements to support life, energy sources, and possible toxic elements. (6) Compare the elemental composition of the northern plains with midlatitude sites. The Icebreaker Life payload has been designed around the Phoenix spacecraft and is targeted to a site near the Phoenix landing site. However, the Icebreaker payload could be supported on other Mars landing systems. Preliminary studies of the SpaceX Dragon lander show that it could support the Icebreaker payload for a landing either at the Phoenix site or at midlatitudes. Duplicate samples could be cached as a target for possible return by

AURORA BOREALIS - Development of a New Research Icebreaker with Drilling Capability

NASA Astrophysics Data System (ADS)

Thiede, J.; Biebow, N.; Egerton, P.; Kunz-Pirrung, M.; Lembke-Jene, L.

2007-12-01

Polar research both on land and in the sea cannot achieve the needed progress without novel and state of the art technologies and infrastructure. In addition, we have the obligation to equip the upcoming young and courageous generation of polar researchers with the most modern and safest research platforms the 21st century can provide. This effort will require major investments, both in terms of generating new tools, as well as maintaining and renovating existing infrastructure. There are many different novel tools under development for polar research, we will concentrate on the presently largest one, the planning for a new type of research icebreaker, the AURORA BOREALIS with an all-season capability of operations in permanently ice-covered waters and with the possibility to carry out deep-sea drilling in ice-covered deep-sea basins. AURORA BOREALIS will be the most advanced Polar Research Vessel in the world with a multi-functional role of drilling in deep ocean basins and supporting climate and environmental research and decision support for stakeholder governments for the next 35 to 40 years. The vessel is planned as a large research icebreaker with 44,000 tons displacement and a length of up to 196 m, with about 50 Megawatt propulsion power. Advanced technological features will include azimuth propulsion systems, extensive instrumental and airborne ice- management support, and the routine operation of Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUVs) from two moon-pools. An unique feature of this icebreaker will be the drilling rig that will enable sampling of the ocean floor and sub-sea down to 5000 m water depth and 1000 m penetration at the most inhospitable places on earth. The possibility to flexibly equip the ship with laboratory and supply containers, and the variable arrangement of other modular infrastructure (in particular, winches, cranes, etc.), free deck- space, and separate protected deck areas, will allow the planned

Zones of impact around icebreakers affecting beluga whales in the Beaufort Sea.

PubMed

Erbe, C; Farmer, D M

2000-09-01

A software model estimating zones of impact on marine mammals around man-made noise [C. Erbe and D. M. Farmer, J. Acoust. Soc. Am. 108, 1327-1331 (2000)] is applied to the case of icebreakers affecting beluga whales in the Beaufort Sea. Two types of noise emitted by the Canadian Coast Guard icebreaker Henry Larsen are analyzed: bubbler system noise and propeller cavitation noise. Effects on beluga whales are modeled both in a deep-water environment and a near-shore environment. The model estimates that the Henry Larsen is audible to beluga whales over ranges of 35-78 km, depending on location. The zone of behavioral disturbance is only slightly smaller. Masking of beluga communication signals is predicted within 14-71-km range. Temporary hearing damage can occur if a beluga stays within 1-4 km of the Henry Larsen for at least 20 min. Bubbler noise impacts over the short ranges quoted; propeller cavitation noise accounts for all the long-range effects. Serious problems can arise in heavily industrialized areas where animals are exposed to ongoing noise and where anthropogenic noise from a variety of sources adds up.

Video Observations Encompassing the 2002 Leonid Storm: First Results and a Revised Photometric Procedure for Video Meteor Analysis

NASA Technical Reports Server (NTRS)

Cooke, William J.; Suggs, Robert; Swift, Wesley; Gural, Peter S.; Brown, Peter; Ellis, Jim (Technical Monitor)

2002-01-01

During the 2001 Leonid storm, Marshall Space Flight Center, with the cooperation of the University of Western Ontario and the United States Air Force, deployed 6 teams of observers equipped with intensified video systems to sites located in North America, the Pacific, and Mongolia. The campaign was extremely successful, with the entire period of enhanced Leonid activity (over 16 hours) captured on video tape in a consistent manner. We present the first results from the analysis of this unique, 2 terabyte data set and discuss the problems involved in reducing large amounts of video meteor data. In particular, the question of how to determine meteor masses though photometric analysis will be re-examined, and new techniques will be proposed that eliminate some of the deficiencies suffered by the techniques currently employed in video meteor analysis.

AURORA BOREALIS - European Research Icebreaker With Drilling Capability

NASA Astrophysics Data System (ADS)

Biebow, N.; Lembke-Jene, L.; Kunz-Pirrung, M.; Thiede, J.

2008-12-01

The polar oceans are the least known areas of the globe, in although they hold the key to many of our climate´s secrets. How does the sea ice coverage and the sea water properties change? How do plants and animals survive under the most extreme conditions of the earth? Which information of past climate change can be read from the sediments at the sea-floor and how can the future changing climate be predicted? In order to answer such and further questions, for the moment a hypermodern research vessel, the AURORA BOREALIS, is planned, which can handle the cool summers and freezing winters of the polar oceans and which can drill deep into the sea floor. AURORA BOREALIS will be the most advanced Research Icebreaker in the world with a multi-functional role of drilling in deep ocean basins and supporting climate/environmental research and decision support for stakeholder governments for the next 35-40 years. It will have a high icebreaking capacity to penetrate autonomously (single ship operation) into the central Arctic Ocean with more than 2.5 meters of ice cover, during all seasons of the year. The new technological features will include dynamic positioning in closed sea- ice cover, satellite navigation and ice-management support and the deployment and operation of Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUVs) from the twin moon-pools. A unique feature of the vessel is the deep-sea drilling rig, which will enable sampling of the ocean floor and sub-sea up to 5000 m water and 1000 m penetration at the most inhospitable places on earth. The drilling capability will be deployed in both Polar Regions on the long run and AURORA BOREALIS will be the only vessel worldwide that could undertake this type of scientific investigation.

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.

The sample handling system for the Mars Icebreaker Life mission: from dirt to data.

PubMed

Davé, Arwen; Thompson, Sarah J; McKay, Christopher P; Stoker, Carol R; Zacny, Kris; Paulsen, Gale; Mellerowicz, Bolek; Glass, Brian J; Willson, David; Bonaccorsi, Rosalba; Rask, Jon

2013-04-01

The Mars Icebreaker Life mission will search for subsurface life on Mars. It consists of three payload elements: a drill to retrieve soil samples from approximately 1 m below the surface, a robotic sample handling system to deliver the sample from the drill to the instruments, and the instruments themselves. This paper will discuss the robotic sample handling system. Collecting samples from ice-rich soils on Mars in search of life presents two challenges: protection of that icy soil--considered a "special region" with respect to planetary protection--from contamination from Earth, and delivery of the icy, sticky soil to spacecraft instruments. We present a sampling device that meets these challenges. We built a prototype system and tested it at martian pressure, drilling into ice-cemented soil, collecting cuttings, and transferring them to the inlet port of the SOLID2 life-detection instrument. The tests successfully demonstrated that the Icebreaker drill, sample handling system, and life-detection instrument can collectively operate in these conditions and produce science data that can be delivered via telemetry--from dirt to data. Our results also demonstrate the feasibility of using an air gap to prevent forward contamination. We define a set of six analog soils for testing over a range of soil cohesion, from loose sand to basalt soil, with angles of repose of 27° and 39°, respectively. Particle size is a key determinant of jamming of mechanical parts by soil particles. Jamming occurs when the clearance between moving parts is equal in size to the most common particle size or equal to three of these particles together. Three particles acting together tend to form bridges and lead to clogging. Our experiments show that rotary-hammer action of the Icebreaker drill influences the particle size, typically reducing particle size by ≈ 100 μm.

The Sample Handling System for the Mars Icebreaker Life Mission: from Dirt to Data

NASA Technical Reports Server (NTRS)

Dave, Arwen; Thompson, Sarah J.; McKay, Christopher P.; Stoker, Carol R.; Zacny, Kris; Paulsen, Gale; Mellerowicz, Bolek; Glass, Brian J.; Wilson, David; Bonaccorsi, Rosalba;

Computer Simulation of Great Lakes-St. Lawrence Seaway Icebreaker Requirements.

DTIC Science & Technology

1980-01-01

of Run No. 1 for Taconite Task Command ... ....... 6-41 6.22d Results of Run No. I for Oil Can Task Command ........ ... 6-42 6.22e Results of Run No...Port and Period for Run No. 2 ... .. ... ... 6-47 6.23c Results of Run No. 2 for Taconite Task Command ... ....... 6-48 6.23d Results of Run No. 2 for...6-53 6.24b Predicted Icebreaker Fleet by Home Port and Period for Run No. 3 6-54 6.24c Results of Run No. 3 for Taconite Task Command. ....... 6

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.

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.

Implementing the Zone of Proximal Development: From the Pedagogical Experiment to the Developmental Education System of Leonid Zankov

ERIC Educational Resources Information Center

Guseva, Liudmila G.; Solomonovich, Mark

2017-01-01

This article overviews the theoretical and applied works of the psychologist and pedagogue Leonid Zankov. Zankov's model of teaching is based on Vygotsky's theory that appropriate teaching methods stimulate cognitive development, whose core notion is the Zone of Proximal Development. This educational psychology research was verified by large scale…

Leonid Vital'evich Kantorovich (on the 100th anniversary of his birth)

NASA Astrophysics Data System (ADS)

Vershik, Anatolii M.; Kutateladze, Semen S.; Novikov, Sergei P.

2012-06-01

The 19th of January 2012 was the 100th anniversary of the birth of Leonid Vital'evich Kantorovich, an outstanding mathematician and economist of international fame. A child prodigy, who graduated from the university at 18 and became a professor at 20, an academician in the mathematical sciences and a laureate of the Nobel Prize in economics, - these are extraordinary circumstances of his life. They are remarkable in themselves, but also the results he achieved were exceptional and immensely impressive, and the younger generations of researchers, first and foremost mathematicians and economists, must know about them.

Drilling Polar Oceans with the European Research Icebreaker AURORA BOREALIS: the IODP Context

NASA Astrophysics Data System (ADS)

Lembke-Jene, Lester; Wolff-Boenisch, Bonnie; Azzolini, Roberto; Thiede, Joern; Biebow, Nicole; Eldholm, Olav; Egerton, Paul

2010-05-01

Polar oceans are characterized by extreme environmental conditions for humans and materials, and have remained the least accessible regions to scientists of the IODP. DSDP and ODP have for long faced specific technical and logistical problems when attempting to drill in ice-covered polar deep-sea basins. The Arctic Ocean and large areas of the high-latitude Southern Ocean remained largely un-sampled by ODP and remain one of the major scientific and technological challenges for IODP. Drilling in these regions has been discussed and anticipated for decades and the scientific rationales are reflected in the science plans of the international Nansen Arctic Drilling Program (NAD) or the Arctic Program Planning Group (APPG) of ODP/IODP, amongst others. More recently, the rationale to investigate the polar oceans in a holistic approach has been outlined by workshops, leading to strategic assessments of the scientific potential and new drilling proposals. The European Polar Board took the initiative to develop a plan for a novel and dedicated research icebreaker with technical capabilities hitherto unrealised. This research icebreaker will enable autonomous operations in the central Arctic Ocean and the Southern Ocean, even during the severest ice conditions in the deep winter, serving all marine disciplines of polar research including scientific drilling: The European Research Icebreaker and Deep-Sea Drilling Vessel AURORA BOREALIS. AURORA BOREALIS is presently planned as a multi-purpose vessel. The ship can be deployed as a research icebreaker in all polar waters during any season of the year, as it shall meet the specifications of the highest ice-class attainable (IACS Polar Code 1) for icebreakers. During the times when it is not employed for drilling, it will operate as the most technically advanced multi-disciplinary research vessel in the Arctic or polar Southern Ocean. AURORA BOREALIS will be a "European scientific flagship facility" (fully open to non

Collecting winter data on U.S. Coast Guard icebreakers

NASA Astrophysics Data System (ADS)

Oyserman, Ben O.; Woityra, William C.; Bullerjahn, George S.; Beall, Benjamin F. N.; McKay, Robert Michael L.

2012-03-01

Winter research and monitoring of icebound rivers, lakes, and coastal seas to date has usually involved seagoing civilian scientists leading survey efforts. However, because of poor weather conditions and a lack of safe research platforms, scientists collecting data during winter face some difficult and often insurmountable problems. To solve these problems and to further research and environmental monitoring goals, new partnerships can be formed through integrating efforts of the U.S. Coast Guard (USCG) with citizen science initiatives. USCG and a research group at Ohio's Bowling Green State University are entering the third year of such a partnership, in which icebreaking operations in Lake Erie using USCG Cutter Neah Bay support volunteer data collection. With two additional USCG vessels joining the program this winter season, the partnership serves as a timely and useful model for worldwide environmental research and monitoring through citizen science and government collaboration.

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.

Icebreaker-3 Drill Integration and Testing at Two Mars-Analog Sites

NASA Technical Reports Server (NTRS)

Glass, B.; Bergman, D.; Yaggi, B.; Dave, A.; Zacny, K.

2016-01-01

A decade of evolutionary development of integrated automated drilling and sample handling at analog sites and in test chambers has made it possible to go 1 meter through hard rocks and ice layers on Mars. The latest Icebreaker-3 drill has been field tested in 2014 at the Haughton Crater Marsanalog site in the Arctic and in 2015 with a Mars lander mockup in Rio Tinto, Spain, (with sample transfer arm and with a prototype life-detection instrument). Tests in Rio Tinto in 2015 successfully demonstrated that the drill sample (cuttings) was handed-off from the drill to the sample transfer arm and thence to the on-deck instrument inlet where it was taken in and analyzed ("dirt-to-data").

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].

Masked hearing thresholds of a beluga whale ( Delphinapterus leucas) in icebreaker noise

NASA Astrophysics Data System (ADS)

Erbe, C.; Farmer, D. M.

An experiment is presented that measured masked hearing thresholds of a beluga whale at the Vancouver Aquarium. The masked signal was a typical beluga vocalization; the masking noise included two types of icebreaker noise and naturally occurring icecracking noise. Thresholds were measured behaviorally in a go/no-go paradigm. Results were that bubbler system noise exhibited the strongest masking effect with a critical noise-to-signal ratio of 15.4 dB. Propeller cavitation noise completely masked the vocalization for noise-to-signal ratios greater than 18.0 dB. Natural icecracking noise showed the least interference with a threshold at 29.0 dB. A psychophysical analysis indicated that the whale did not have a consistent decision bias.

Air-sea interaction regimes in the sub-Antarctic Southern Ocean and Antarctic marginal ice zone revealed by icebreaker measurements

NASA Astrophysics Data System (ADS)

Yu, Lisan; Jin, Xiangze; Schulz, Eric W.; Josey, Simon A.

2017-08-01

This study analyzed shipboard air-sea measurements acquired by the icebreaker Aurora Australis during its off-winter operation in December 2010 to May 2012. Mean conditions over 7 months (October-April) were compiled from a total of 22 ship tracks. The icebreaker traversed the water between Hobart, Tasmania, and the Antarctic continent, providing valuable in situ insight into two dynamically important, yet poorly sampled, regimes: the sub-Antarctic Southern Ocean and the Antarctic marginal ice zone (MIZ) in the Indian Ocean sector. The transition from the open water to the ice-covered surface creates sharp changes in albedo, surface roughness, and air temperature, leading to consequential effects on air-sea variables and fluxes. Major effort was made to estimate the air-sea fluxes in the MIZ using the bulk flux algorithms that are tuned specifically for the sea-ice effects, while computing the fluxes over the sub-Antarctic section using the COARE3.0 algorithm. The study evidenced strong sea-ice modulations on winds, with the southerly airflow showing deceleration (convergence) in the MIZ and acceleration (divergence) when moving away from the MIZ. Marked seasonal variations in heat exchanges between the atmosphere and the ice margin were noted. The monotonic increase in turbulent latent and sensible heat fluxes after summer turned the MIZ quickly into a heat loss regime, while at the same time the sub-Antarctic surface water continued to receive heat from the atmosphere. The drastic increase in turbulent heat loss in the MIZ contrasted sharply to the nonsignificant and seasonally invariant turbulent heat loss over the sub-Antarctic open water.