The Physical Characterization of the Potentially-‐Hazardous
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SPECIAL Comet Shoemaker-Levy 9 Collides with Jupiter
SL-9/JUPITER ENCOUNTER - SPECIAL Comet Shoemaker-Levy 9 Collides with Jupiter THE CONTINUATION OF A UNIQUE EXPERIENCE R.M. WEST, ESO-Garching After the Storm Six Hectic Days in July eration during the first nights and, as in other places, an extremely rich data The recent demise of comet Shoe ESO was but one of many profes material was secured. It quickly became maker-Levy 9, for simplicity often re sional observatories where observations evident that infrared observations, es ferred to as "SL-9", was indeed spectac had been planned long before the critical pecially imaging with the far-IR instru ular. The dramatic collision of its many period of the "SL-9" event, July 16-22, ment TIMMI at the 3.6-metre telescope, fragments with the giant planet Jupiter 1994. It is now clear that practically all were perfectly feasible also during day during six hectic days in July 1994 will major observatories in the world were in time, and in the end more than 120,000 pass into the annals of astronomy as volved in some way, via their telescopes, images were obtained with this facility. one of the most incredible events ever their scientists or both. The only excep The programmes at most of the other predicted and witnessed by members of tions may have been a few observing La Silla telescopes were also successful, this profession. And never before has a sites at the northernmost latitudes where and many more Gigabytes of data were remote astronomical event been so ac the bright summer nights and the very recorded with them. -
KAREN J. MEECH February 7, 2019 Astronomer
BIOGRAPHICAL SKETCH – KAREN J. MEECH February 7, 2019 Astronomer Institute for Astronomy Tel: 1-808-956-6828 2680 Woodlawn Drive Fax: 1-808-956-4532 Honolulu, HI 96822-1839 [email protected] PROFESSIONAL PREPARATION Rice University Space Physics B.A. 1981 Massachusetts Institute of Tech. Planetary Astronomy Ph.D. 1987 APPOINTMENTS 2018 – present Graduate Chair 2000 – present Astronomer, Institute for Astronomy, University of Hawaii 1992-2000 Associate Astronomer, Institute for Astronomy, University of Hawaii 1987-1992 Assistant Astronomer, Institute for Astronomy, University of Hawaii 1982-1987 Graduate Research & Teaching Assistant, Massachusetts Inst. Tech. 1981-1982 Research Specialist, AAVSO and Massachusetts Institute of Technology AWARDS 2018 ARCs Scientist of the Year 2015 University of Hawai’i Regent’s Medal for Research Excellence 2013 Director’s Research Excellence Award 2011 NASA Group Achievement Award for the EPOXI Project Team 2011 NASA Group Achievement Award for EPOXI & Stardust-NExT Missions 2009 William Tylor Olcott Distinguished Service Award of the American Association of Variable Star Observers 2006-8 National Academy of Science/Kavli Foundation Fellow 2005 NASA Group Achievement Award for the Stardust Flight Team 1996 Asteroid 4367 named Meech 1994 American Astronomical Society / DPS Harold C. Urey Prize 1988 Annie Jump Cannon Award 1981 Heaps Physics Prize RESEARCH FIELD AND ACTIVITIES • Developed a Discovery mission concept to explore the origin of Earth’s water. • Co-Investigator on the Deep Impact, Stardust-NeXT and EPOXI missions, leading the Earth-based observing campaigns for all three. • Leads the UH Astrobiology Research interdisciplinary program, overseeing ~30 postdocs and coordinating the research with ~20 local faculty and international partners. -
Early Observations of the Interstellar Comet 2I/Borisov
geosciences Article Early Observations of the Interstellar Comet 2I/Borisov Chien-Hsiu Lee NSF’s National Optical-Infrared Astronomy Research Laboratory, Tucson, AZ 85719, USA; [email protected]; Tel.: +1-520-318-8368 Received: 26 November 2019; Accepted: 11 December 2019; Published: 17 December 2019 Abstract: 2I/Borisov is the second ever interstellar object (ISO). It is very different from the first ISO ’Oumuamua by showing cometary activities, and hence provides a unique opportunity to study comets that are formed around other stars. Here we present early imaging and spectroscopic follow-ups to study its properties, which reveal an (up to) 5.9 km comet with an extended coma and a short tail. Our spectroscopic data do not reveal any emission lines between 4000–9000 Angstrom; nevertheless, we are able to put an upper limit on the flux of the C2 emission line, suggesting modest cometary activities at early epochs. These properties are similar to comets in the solar system, and suggest that 2I/Borisov—while from another star—is not too different from its solar siblings. Keywords: comets: general; comets: individual (2I/Borisov); solar system: formation 1. Introduction 2I/Borisov was first seen by Gennady Borisov on 30 August 2019. As more observations were conducted in the next few days, there was growing evidence that this might be an interstellar object (ISO), especially its large orbital eccentricity. However, the first astrometric measurements do not have enough timespan and are not of same quality, hence the high eccentricity is yet to be confirmed. This had all changed by 11 September; where more than 100 astrometric measurements over 12 days, Ref [1] pinned down the orbit elements of 2I/Borisov, with an eccentricity of 3.15 ± 0.13, hence confirming the interstellar nature. -
Origin and Evolution of Trojan Asteroids 725
Marzari et al.: Origin and Evolution of Trojan Asteroids 725 Origin and Evolution of Trojan Asteroids F. Marzari University of Padova, Italy H. Scholl Observatoire de Nice, France C. Murray University of London, England C. Lagerkvist Uppsala Astronomical Observatory, Sweden The regions around the L4 and L5 Lagrangian points of Jupiter are populated by two large swarms of asteroids called the Trojans. They may be as numerous as the main-belt asteroids and their dynamics is peculiar, involving a 1:1 resonance with Jupiter. Their origin probably dates back to the formation of Jupiter: the Trojan precursors were planetesimals orbiting close to the growing planet. Different mechanisms, including the mass growth of Jupiter, collisional diffusion, and gas drag friction, contributed to the capture of planetesimals in stable Trojan orbits before the final dispersal. The subsequent evolution of Trojan asteroids is the outcome of the joint action of different physical processes involving dynamical diffusion and excitation and collisional evolution. As a result, the present population is possibly different in both orbital and size distribution from the primordial one. No other significant population of Trojan aster- oids have been found so far around other planets, apart from six Trojans of Mars, whose origin and evolution are probably very different from the Trojans of Jupiter. 1. INTRODUCTION originate from the collisional disruption and subsequent reaccumulation of larger primordial bodies. As of May 2001, about 1000 asteroids had been classi- A basic understanding of why asteroids can cluster in fied as Jupiter Trojans (http://cfa-www.harvard.edu/cfa/ps/ the orbit of Jupiter was developed more than a century lists/JupiterTrojans.html), some of which had only been ob- before the first Trojan asteroid was discovered. -
Interstellar Comet 2I/Borisov
Interstellar comet 2I/Borisov Piotr Guzik1*, Michał Drahus1*, Krzysztof Rusek2, Wacław Waniak1, Giacomo Cannizzaro3,4, Inés Pastor-Marazuela5,6 1 Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland 2 AGH University of Science and Technology, al. Mickiewicza 30, Kraków 30-059, Poland 3 SRON, Netherlands Institute for Space Research, Sorbonnelaan, 2, NL-3584CA Utrecht, the Netherlands 4 Department of Astrophysics/IMAPP, Radboud University, P.O. Box 9010, 6500 GL Nijmegen, the Netherlands 5 Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands 6 ASTRON, Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands * These authors contributed equally to this work. Interstellar comets penetrating through the Solar System were anticipated for decades1,2. The discovery of non-cometary 1I/‘Oumuamua by Pan-STARRS was therefore a huge surprise and puzzle. Furthermore, its physical properties turned out to be impossible to reconcile with Solar System objects3-5, which radically changed our view on interstellar minor bodies. Here, we report the identification of a new interstellar object which has an evidently cometary appearance. The body was identified by our data mining code in publicly available astrometric data. The data clearly show significant systematic deviation from what is expected for a parabolic orbit and are consistent with an enormous orbital eccentricity of 3.14 ± 0.14. Images taken by the William Herschel Telescope and Gemini North telescope show an extended coma and a faint, broad tail – the canonical signatures of cometary activity. The observed g’ and r’ magnitudes are equal to 19.32 ± 0.02 and 18.69 ± 0.02, respectively, implying g’-r’ color index of 0.63 ± 0.03, essentially the same as measured for the native Solar System comets. -
Initial Characterization of Interstellar Comet 2I/Borisov
Initial characterization of interstellar comet 2I/Borisov Piotr Guzik1*, Michał Drahus1*, Krzysztof Rusek2, Wacław Waniak1, Giacomo Cannizzaro3,4, Inés Pastor-Marazuela5,6 1 Astronomical Observatory, Jagiellonian University, Kraków, Poland 2 AGH University of Science and Technology, Kraków, Poland 3 SRON, Netherlands Institute for Space Research, Utrecht, the Netherlands 4 Department of Astrophysics/IMAPP, Radboud University, Nijmegen, the Netherlands 5 Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, the Netherlands 6 ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, the Netherlands * These authors contributed equally to this work; email: [email protected], [email protected] Interstellar comets penetrating through the Solar System had been anticipated for decades1,2. The discovery of asteroidal-looking ‘Oumuamua3,4 was thus a huge surprise and a puzzle. Furthermore, the physical properties of the ‘first scout’ turned out to be impossible to reconcile with Solar System objects4–6, challenging our view of interstellar minor bodies7,8. Here, we report the identification and early characterization of a new interstellar object, which has an evidently cometary appearance. The body was discovered by Gennady Borisov on 30 August 2019 UT and subsequently identified as hyperbolic by our data mining code in publicly available astrometric data. The initial orbital solution implies a very high hyperbolic excess speed of ~32 km s−1, consistent with ‘Oumuamua9 and theoretical predictions2,7. Images taken on 10 and 13 September 2019 UT with the William Herschel Telescope and Gemini North Telescope show an extended coma and a faint, broad tail. We measure a slightly reddish colour with a g′–r′ colour index of 0.66 ± 0.01 mag, compatible with Solar System comets. -
The Orbital Distribution of Near-Earth Objects Inside Earth’S Orbit
Icarus 217 (2012) 355–366 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus The orbital distribution of Near-Earth Objects inside Earth’s orbit ⇑ Sarah Greenstreet a, , Henry Ngo a,b, Brett Gladman a a Department of Physics & Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, British Columbia, Canada b Department of Physics, Engineering Physics, and Astronomy, 99 University Avenue, Queen’s University, Kingston, Ontario, Canada article info abstract Article history: Canada’s Near-Earth Object Surveillance Satellite (NEOSSat), set to launch in early 2012, will search for Received 17 August 2011 and track Near-Earth Objects (NEOs), tuning its search to best detect objects with a < 1.0 AU. In order Revised 8 November 2011 to construct an optimal pointing strategy for NEOSSat, we needed more detailed information in the Accepted 9 November 2011 a < 1.0 AU region than the best current model (Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.M., Levison, Available online 28 November 2011 H.F., Michel, P., Metcalfe, T.S. [2002]. Icarus 156, 399–433) provides. We present here the NEOSSat-1.0 NEO orbital distribution model with larger statistics that permit finer resolution and less uncertainty, Keywords: especially in the a < 1.0 AU region. We find that Amors = 30.1 ± 0.8%, Apollos = 63.3 ± 0.4%, Atens = Near-Earth Objects 5.0 ± 0.3%, Atiras (0.718 < Q < 0.983 AU) = 1.38 ± 0.04%, and Vatiras (0.307 < Q < 0.718 AU) = 0.22 ± 0.03% Celestial mechanics Impact processes of the steady-state NEO population. -
Carbon Monoxide in Jupiter After Comet Shoemaker-Levy 9
ICARUS 126, 324±335 (1997) ARTICLE NO. IS965655 Carbon Monoxide in Jupiter after Comet Shoemaker±Levy 9 1 1 KEITH S. NOLL AND DIANE GILMORE Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218 E-mail: [email protected] 1 ROGER F. KNACKE AND MARIA WOMACK Pennsylvania State University, Erie, Pennsylvania 16563 1 CAITLIN A. GRIFFITH Northern Arizona University, Flagstaff, Arizona 86011 AND 1 GLENN ORTON Jet Propulsion Laboratory, Pasadena, California 91109 Received February 5, 1996; revised November 5, 1996 for roughly half the mass. In high-temperature shocks, Observations of the carbon monoxide fundamental vibra- most of the O is converted to CO (Zahnle and MacLow tion±rotation band near 4.7 mm before and after the impacts 1995), making CO one of the more abundant products of of the fragments of Comet Shoemaker±Levy 9 showed no de- a large impact. tectable changes in the R5 and R7 lines, with one possible By contrast, oxygen is a rare element in Jupiter's upper exception. Observations of the G-impact site 21 hr after impact atmosphere. The principal reservoir of oxygen in Jupiter's do not show CO emission, indicating that the heated portions atmosphere is water. The Galileo Probe Mass Spectrome- of the stratosphere had cooled by that time. The large abun- ter found a mixing ratio of H OtoH of X(H O) # 3.7 3 dances of CO detected at the millibar pressure level by millime- 2 2 2 24 P et al. ter wave observations did not extend deeper in Jupiter's atmo- 10 at P 11 bars (Niemann 1996). -
Solar System Planet and Dwarf Planet Fact Sheet
Solar System Planet and Dwarf Planet Fact Sheet The planets and dwarf planets are listed in their order from the Sun. Mercury The smallest planet in the Solar System. The closest planet to the Sun. Revolves the fastest around the Sun. It is 1,000 degrees Fahrenheit hotter on its daytime side than on its night time side. Venus The hottest planet. Average temperature: 864 F. Hotter than your oven at home. It is covered in clouds of sulfuric acid. It rains sulfuric acid on Venus which comes down as virga and does not reach the surface of the planet. Its atmosphere is mostly carbon dioxide (CO2). It has thousands of volcanoes. Most are dormant. But some might be active. Scientists are not sure. It rotates around its axis slower than it revolves around the Sun. That means that its day is longer than its year! This rotation is the slowest in the Solar System. Earth Lots of water! Mountains! Active volcanoes! Hurricanes! Earthquakes! Life! Us! Mars It is sometimes called the "red planet" because it is covered in iron oxide -- a substance that is the same as rust on our planet. It has the highest volcano -- Olympus Mons -- in the Solar System. It is not an active volcano. It has a canyon -- Valles Marineris -- that is as wide as the United States. It once had rivers, lakes and oceans of water. Scientists are trying to find out what happened to all this water and if there ever was (or still is!) life on Mars. It sometimes has dust storms that cover the entire planet. -
THE DISTRIBUTION of ASTEROIDS: EVIDENCE from ANTARCTIC MICROMETEORITES. M. J. Genge and M. M. Grady, Department of Mineralogy, T
Lunar and Planetary Science XXXIII (2002) 1010.pdf THE DISTRIBUTION OF ASTEROIDS: EVIDENCE FROM ANTARCTIC MICROMETEORITES. M. J. Genge and M. M. Grady, Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD (email: [email protected]). Introduction: Antarctic micrometeorites (AMMs) due to aqueous alteration. Some C2 fgMMs contain are that fraction of the Earth's cosmic dust flux that tochilinite and are probably directly related to the CM2 survive atmospheric entry to be recovered from Antar- chondrites, however, others may differ from CMs in tic ice. Models of atmospheric entry indicate that, due their mineralogy. to their large size (>50 µm), unmelted AMMs are de- C1 fgMMs are particles with compact matrices that rived mainly from low geocentric velocity sources such are homogeneous in Fe/Mg and show little contrast in as the main belt asteroids [1]. The production of dust in BEIs. These are similar to the CI1 chondrites and do the main belt by small erosive collisions and the deliv- not contain recognisable psuedomorphs after anhy- ery of dust-sized debris to Earth by P-R light drag drous silicates and thus have been intensely altered by should ensure that AMMs are a much more representa- water. C1 fgMMs often contain framboidal magnetite tive sample of main belt asteroids than meteorites. clusters. The relative abundances of different petrological C3 fgMMs have porous matrices (often around types amongst 550 AMMs collected from Cap Prud- 50% by volume) and are dominated by micron-sized homme [2] is reported and compared with the abun- Mg-rich olivine and pyroxenes linked by a network of dances of asteroid spectral-types in the main belt. -
Detection of Exocometary CO Within the 440 Myr Old Fomalhaut Belt: a Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets
UCLA UCLA Previously Published Works Title Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets Permalink https://escholarship.org/uc/item/1zf7t4qn Journal Astrophysical Journal, 842(1) ISSN 0004-637X Authors Matra, L MacGregor, MA Kalas, P et al. Publication Date 2017-06-10 DOI 10.3847/1538-4357/aa71b4 Peer reviewed eScholarship.org Powered by the California Digital Library University of California The Astrophysical Journal, 842:9 (15pp), 2017 June 10 https://doi.org/10.3847/1538-4357/aa71b4 © 2017. The American Astronomical Society. All rights reserved. Detection of Exocometary CO within the 440 Myr Old Fomalhaut Belt: A Similar CO+CO2 Ice Abundance in Exocomets and Solar System Comets L. Matrà1, M. A. MacGregor2, P. Kalas3,4, M. C. Wyatt1, G. M. Kennedy1, D. J. Wilner2, G. Duchene3,5, A. M. Hughes6, M. Pan7, A. Shannon1,8,9, M. Clampin10, M. P. Fitzgerald11, J. R. Graham3, W. S. Holland12, O. Panić13, and K. Y. L. Su14 1 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK; [email protected] 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3 Astronomy Department, University of California, Berkeley CA 94720-3411, USA 4 SETI Institute, Mountain View, CA 94043, USA 5 Univ. Grenoble Alpes/CNRS, IPAG, F-38000 Grenoble, France 6 Department of Astronomy, Van Vleck Observatory, Wesleyan University, 96 Foss Hill Dr., Middletown, CT 06459, USA 7 MIT Department of Earth, Atmospheric, and -
19. Near-Earth Objects Chelyabinsk Meteor: 2013 ~0.5 Megaton Airburst ~1500 People Injured
Astronomy 241: Foundations of Astrophysics I 19. Near-Earth Objects Chelyabinsk Meteor: 2013 ~0.5 megaton airburst ~1500 people injured (C) Don Davis Asteroids 101 — B612 Foundation Great Daylight Fireball: 1972 Earthgrazer: The Great Daylight Fireball of 1972 Tunguska Meteor: 1908 Asteroid or comet: D ~ 40 m ~10 megaton airburst ~40 km destruction radius The Tunguska Impact Tunguska: The Largest Recent Impact Event Barringer Crater: ~50 ky BP M-type asteroid: D ~ 50 m ~10 megaton impact 1.2 km crater diameter Meteor Crater — Wikipedia Chicxulub Crater: ~65 My BP Asteroid: D ~ 10 km 180 km crater diameter Chicxulub Crater— Wikipedia Comets and Meteor Showers Comets shed dust and debris which slowly spread out as they move along the comet’s orbit. If the Earth encounters one of these trails, we get a Breakup of a Comet meteor shower. Meteor Stream Perseid Meteor Shower Raining Perseids Major Meteor Showers Forty Thousand Meteor Origins Across the Sky Known Potentially-Hazardous Objects Near-Earth object — Wikipedia Near-Earth object — Wikipedia Origin of Near-Earth Objects (NEOs) ! WHAM Mars Some fragments wind up on orbits which are resonant with Jupiter. Their orbits grow more elliptical, finally entering the inner solar system. Wikipedia: Asteroid belt Asteroid Families Many asteroids are members of families; they have similar orbits and compositions (indicated by colors). Asteroid Belt Populations Inner belt asteroids (left) and families (right). Origin of Key Stages in the Evolution of the Asteroid Vesta Processed Family Members Crust Surface Magnesium-Sliicate Lavas Meteorites Mantle (Olivine) Iron-Nickle Core Stony Irons? As smaller bodies in the early Solar System Heavier elements sink to the Occasional impacts with other bodies fall together, the asteroid agglomerates.