The Active Asteroids
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Occultation Evidence for a Satellite of the Trojan Asteroid (911) Agamemnon Bradley Timerson1, John Brooks2, Steven Conard3, David W
Occultation Evidence for a Satellite of the Trojan Asteroid (911) Agamemnon Bradley Timerson1, John Brooks2, Steven Conard3, David W. Dunham4, David Herald5, Alin Tolea6, Franck Marchis7 1. International Occultation Timing Association (IOTA), 623 Bell Rd., Newark, NY, USA, [email protected] 2. IOTA, Stephens City, VA, USA, [email protected] 3. IOTA, Gamber, MD, USA, [email protected] 4. IOTA, KinetX, Inc., and Moscow Institute of Electronics and Mathematics of Higher School of Economics, per. Trekhsvyatitelskiy B., dom 3, 109028, Moscow, Russia, [email protected] 5. IOTA, Murrumbateman, NSW, Australia, [email protected] 6. IOTA, Forest Glen, MD, USA, [email protected] 7. Carl Sagan Center at the SETI Institute, 189 Bernardo Av, Mountain View CA 94043, USA, [email protected] Corresponding author Franck Marchis Carl Sagan Center at the SETI Institute 189 Bernardo Av Mountain View CA 94043 USA [email protected] 1 Keywords: Asteroids, Binary Asteroids, Trojan Asteroids, Occultation Abstract: On 2012 January 19, observers in the northeastern United States of America observed an occultation of 8.0-mag HIP 41337 star by the Jupiter-Trojan (911) Agamemnon, including one video recorded with a 36cm telescope that shows a deep brief secondary occultation that is likely due to a satellite, of about 5 km (most likely 3 to 10 km) across, at 278 km ±5 km (0.0931″) from the asteroid’s center as projected in the plane of the sky. A satellite this small and this close to the asteroid could not be resolved in the available VLT adaptive optics observations of Agamemnon recorded in 2003. -
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. -
(101955) Bennu from OSIRIS-Rex Imaging and Thermal Analysis
ARTICLES https://doi.org/10.1038/s41550-019-0731-1 Properties of rubble-pile asteroid (101955) Bennu from OSIRIS-REx imaging and thermal analysis D. N. DellaGiustina 1,26*, J. P. Emery 2,26*, D. R. Golish1, B. Rozitis3, C. A. Bennett1, K. N. Burke 1, R.-L. Ballouz 1, K. J. Becker 1, P. R. Christensen4, C. Y. Drouet d’Aubigny1, V. E. Hamilton 5, D. C. Reuter6, B. Rizk 1, A. A. Simon6, E. Asphaug1, J. L. Bandfield 7, O. S. Barnouin 8, M. A. Barucci 9, E. B. Bierhaus10, R. P. Binzel11, W. F. Bottke5, N. E. Bowles12, H. Campins13, B. C. Clark7, B. E. Clark14, H. C. Connolly Jr. 15, M. G. Daly 16, J. de Leon 17, M. Delbo’18, J. D. P. Deshapriya9, C. M. Elder19, S. Fornasier9, C. W. Hergenrother1, E. S. Howell1, E. R. Jawin20, H. H. Kaplan5, T. R. Kareta 1, L. Le Corre 21, J.-Y. Li21, J. Licandro17, L. F. Lim6, P. Michel 18, J. Molaro21, M. C. Nolan 1, M. Pajola 22, M. Popescu 17, J. L. Rizos Garcia 17, A. Ryan18, S. R. Schwartz 1, N. Shultz1, M. A. Siegler21, P. H. Smith1, E. Tatsumi23, C. A. Thomas24, K. J. Walsh 5, C. W. V. Wolner1, X.-D. Zou21, D. S. Lauretta 1 and The OSIRIS-REx Team25 Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the for- mation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA’s Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft, we show that asteroid (101955) Bennu’s surface is globally rough, dense with boulders, and low in albedo. -
Disintegration of Active Asteroid P/2016 G1 (PANSTARRS) Olivier R
A&A 628, A48 (2019) https://doi.org/10.1051/0004-6361/201935868 Astronomy & © ESO 2019 Astrophysics Disintegration of active asteroid P/2016 G1 (PANSTARRS) Olivier R. Hainaut1, Jan T. Kleyna2, Karen J. Meech2, Mark Boslough3, Marco Micheli4,5, Richard Wainscoat2, Marielle Dela Cruz2, Jacqueline V. Keane2, Devendra K. Sahu6, and Bhuwan C. Bhatt6 1 European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany e-mail: [email protected] 2 Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 3 University of NM – 1700 Lomas Blvd, NE. Suite 2200, Albuquerque, NM 87131-0001 USA 4 ESA SSA-NEO Coordination Centre, Largo Galileo Galilei, 1 00044 Frascati (RM), Italy 5 INAF – Osservatorio Astronomico di Roma, Via Frascati, 33, 00040 Monte Porzio Catone (RM), Italy 6 Indian Institute of Astrophysics, II Block, Koramangala, Bengaluru 560 034, India Received 10 May 2019 / Accepted 26 June 2019 ABSTRACT We report on the catastrophic disintegration of P/2016 G1 (PANSTARRS), an active asteroid, in April 2016. Deep images over three months show that the object is made up of a central concentration of fragments surrounded by an elongated coma, and presents previously unreported sharp arc-like and narrow linear features. The morphology and evolution of these characteristics independently point toward a brief event on 2016 March 6. The arc and the linear feature can be reproduced by large particles on a ring, moving at ∼2:5 m s−1. The expansion of the ring defines a cone with a ∼40◦ half-opening. We propose that the P/2016 G1 was hit by a small object which caused its (partial or total) disruption, and that the ring corresponds to large fragments ejected during the final stages of the crater formation. -
Polarimetric and Photometric Observations of Neas with the 1.6M Pirka Telescope
PPS03-P17 Japan Geoscience Union Meeting 2018 Polarimetric and Photometric observations of NEAs with the 1.6m Pirka Telescope *Ryo Okazaki1, Tomohiko Sekiguchi1, Akari Kamada1, Masateru Ishiguro2, Hiroyuki Naito3, Masataka Imai4, Tatsuharu Ono4 1. Hokkaido University of Education, 2. Seoul National University, 3. Nayoro Observatory, 4. Hokkaido University Polarimetric observations of 3 near-Earth asteroids, 2000 PD3, 2012 TC4 and (3200) Phaethon, were carried out in 2017 using the 1.6m Pirka telescope at the Nayoro Observatory, Hokkaido, as well as BVRIphotometric color observations were conducted for 2000 PD3. Polarimetry is a useful method for investigating asteroids’ physical properties such as the albedo, regolith particle size and taxonomy of asteroids. In general, Pr (the linear polarization degree) exhibits a strong dependence on the phase angle (Sun-Target-Observer’s angle, α). 2000 PD3 In order to understand Pmax (maximum Polarization degree) , we attempted to obtain polarimetric data at different phase angles (α=22°-120°). A geometric albedo of pv=0.26±0.06% were derived from a limited αrange ( 25°-84°) which is in good agreement with that of S-type asteroids. BVRI photometric data (B-V=0.132±0.002mag,V-R=0.114±0.002mag,V-I=0.180±0.002mag) supports S-type classification. 2012 TC4 In October 2017, 2012 TC4 approached to the Earth at about 50,000 km of the closest distance. A fast rotation period about 0.2 hours (Ryan and Ryan, 2017) indicates a monolithic suraface layer which is not covered with a rubble pile. The liner polarization Pr=5.62±5.26% (α=34°) in the R-band is in close accord with that of C-type asteroids, although October run was performed under bad weather. -
14790 (Stsci Edit Number: 0, Created: Friday, July 29, 2016 2:42:55 PM EST) - Overview
Proposal 14790 (STScI Edit Number: 0, Created: Friday, July 29, 2016 2:42:55 PM EST) - Overview 14790 - Investigating the binary nature of active asteroid 288P/300163 Cycle: 24, Proposal Category: GO (Availability Mode: SUPPORTED) INVESTIGATORS Name Institution E-Mail Dr. Jessica Agarwal (PI) (ESA Member) (Conta Max Planck Institute for Solar System Research [email protected] ct) Dr. David Jewitt (CoI) (AdminUSPI) (Contact) University of California - Los Angeles [email protected] Dr. Harold A. Weaver (CoI) (Contact) The Johns Hopkins University Applied Physics Labor [email protected] atory Max Mutchler (CoI) (Contact) Space Telescope Science Institute [email protected] Dr. Stephen M. Larson (CoI) University of Arizona [email protected] VISITS Visit Targets used in Visit Configurations used in Visit Orbits Used Last Orbit Planner Run OP Current with Visit? 01 (1) 288P WFC3/UVIS 1 29-Jul-2016 15:42:51.0 yes 02 (1) 288P WFC3/UVIS 1 29-Jul-2016 15:42:52.0 yes 03 (1) 288P WFC3/UVIS 1 29-Jul-2016 15:42:53.0 yes 04 (1) 288P WFC3/UVIS 1 29-Jul-2016 15:42:54.0 yes 05 (1) 288P WFC3/UVIS 1 29-Jul-2016 15:42:54.0 yes 5 Total Orbits Used ABSTRACT We propose to study the suspected binary nature of active asteroid 288P/300163. We aim to confirm or disprove the existence of a binary nucleus, and - if confirmed - to measure the mutual orbital period and orbit orientation of the compoents, and their sizes. We request 5 orbits of WFC3 1 Proposal 14790 (STScI Edit Number: 0, Created: Friday, July 29, 2016 2:42:55 PM EST) - Overview imaging, spaced at intervals of 8-12 days. -
The Blurring Distinction Between Asteroids and Comets
Answers Research Journal 8 (2015):203–208. www.answersingenesis.org/arj/v8/asteroids-and-comets.pdf The Blurring Distinction between Asteroids and Comets Danny R. Faulkner, Answers in Genesis, PO Box 510, Hebron, Kentucky, 41048. Abstract Asteroids and comets long had been viewed as distinct objects with regards to orbits and composition. However, discoveries made in recent years have blurred those distinctions. Whether there is a continuum on which our older conception of asteroids and comets are extremes or if there still is a gap between them is not entirely clear yet. Some of the newer views of comets and asteroids may challenge the evolutionary theory of the solar system. Additionally, the new information may challenge the idea that the solar system is billions of years old. For readers not versed in nomenclature of small solar system bodies, I discuss that in the appendix. Keywords: small solar system objects, comets, asteroids (minor planets) Introduction the sun, and their orbits frequently are inclined The differences between asteroids and comets considerably to the orbits of the planets. Because of At one time, we thought of asteroids and comets as their highly elliptical orbits, most comets alternately being two very different groups of objects. Comets and are very close to the sun when near perihelion and asteroids certainly looked different. Comets can be very far from the sun when near aphelion. Comets visible to the naked eye, and have been known since spend most of the time near aphelion far from the ancient times. They have a hazy, fuzzy appearance. sun, so that their ices remain frozen. -
Impact Process of Boulders on the Surface of Asteroid 25143 Itokawa— Fragments from Collisional Disruption
Earth Planets Space, 60, 7–12, 2008 Impact process of boulders on the surface of asteroid 25143 Itokawa— fragments from collisional disruption A. M. Nakamura1, T. Michikami2, N. Hirata3, A. Fujiwara4, R. Nakamura5, M. Ishiguro6, H. Miyamoto7,8, H. Demura3, K. Hiraoka1, T. Honda1, C. Honda4, J. Saito9, T. Hashimoto4, and T. Kubota4 1Graduate School of Science, Kobe University, Kobe, 657-8501, Japan 2Fukushima National College of Technology, Iwaki, Fukushima 970-8034, Japan 3School of Computer Science and Engineering, University of Aizu, Aizuwakamatsu, Fukushima 965-8580, Japan 4Institute of Space and Astronautical Sciences (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 229-8510, Japan 5National Institute of Advanced Industrial Science and Technology, Tsukuba 306-8568, Japan 6Astronomy Department, Seoul National University, Seoul 151-747, Korea 7The University Museum, University of Tokyo, Tokyo 113-0033, Japan 8Planetary Science Institute, Tucson, AZ 85719, USA 9School of Engineering, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan (Received November 3, 2006; Revised March 29, 2007; Accepted April 11, 2007; Online published February 12, 2008) The subkilometer-size asteroid 25143 Itokawa is considered to have a gravitationally bounded rubble-pile structure. Boulders appearing in high-resolution images retrieved by the Hayabusa mission revealed the genuine outcome of the collisional event involving the asteroid’s parent body. Here we report that the boulders’ shapes and structures are strikingly similar to laboratory rock impact fragments despite differences of orders of magnitude in scale and complexities of the physical processes. These similarities suggest the universal character of the process throughout the range of these scales, and the brittle and structurally continuous nature regarding the parent body of the boulders. -
Adaptive Optics Observations of Asteroid (216) Kleopatra
A&A 394, 339–343 (2002) Astronomy DOI: 10.1051/0004-6361:20021094 & c ESO 2002 Astrophysics Research Note Adaptive optics observations of asteroid (216) Kleopatra D. Hestroffer1,F.Marchis2,, T. Fusco3, and J. Berthier1 1 IMCCE, UMR CNRS 8028, Paris Observatory, 77 Av. Denfert Rochereau, 75014 Paris, France 2 CFAO/University of California, Dept. of Astronomy, 601 Campbell Hall, Berkeley, CA 94720, USA 3 ONERA, DOTA-E, BP 72, 92322 Chˆatillon, France Received 22 March 2002 / Accepted 11 July 2002 Abstract. The large main-belt asteroid (216) Kleopatra has been for long suspected to be a binary object, mainly due to its large lightcurve amplitude. However, recent observations suggest that it is a single “bone-shaped” or bi-lobated body (Ostro et al. 2000; Tanga et al. 2001). We present results obtained from ground-based adaptive optics observations, and in agreement with the radar raw-observations, the images show two prominent lobes. Making use of the MISTRAL deconvolution technique, the restored images yield a well-separated binary object. Nevertheless, the spatial resolution of the 3.6 m ESO telescope is limited and a dumbbell-shaped body could yield similar features. Further simulations show that adaptive optics observations with an 8-meter class telescope analyzed with the powerful MISTRAL deconvolution technique could overcome this limitation. Key words. instrumentation: adaptive optics – minor planets, asteroids 1. Introduction provide additional constraints on collisional-evolution and binary-formation models. At the beginning of last century, by analyzing the asteroid Direct or indirect imaging of Kleopatra in the past showed (433) Eros, Andr´e made the hypothesis that asteroids could it to be a very elongated body but was not able to conclusively have satellites (Andr´e 1901). -
1. Some of the Definitions of the Different Types of Objects in the Solar
1. Some of the definitions of the different types of objects in has the greatest orbital inclination (orbit at the the solar system overlap. Which one of the greatest angle to that of Earth)? following pairs does not overlap? That is, if an A) Mercury object can be described by one of the labels, it B) Mars cannot be described by the other. C) Jupiter A) dwarf planet and asteroid D) Pluto B) dwarf planet and Kuiper belt object C) satellite and Kuiper belt object D) meteoroid and planet 10. Of the following objects in the solar system, which one has the greatest orbital eccentricity and therefore the most elliptical orbit? 2. Which one of the following is a small solar system body? A) Mercury A) Rhea, a moon of Saturn B) Mars B) Pluto C) Earth C) Ceres (an asteroid) D) Pluto D) Mathilde (an asteroid) 11. What is the largest moon of the dwarf planet Pluto 3. Which of the following objects was discovered in the called? twentieth century? A) Chiron A) Pluto B) Callisto B) Uranus C) Charon C) Neptune D) Triton D) Ceres 12. If you were standing on Pluto, how often would you see 4. Pluto was discovered in the satellite Charon rise above the horizon each A) 1930. day? B) 1846. A) once each 6-hour day as Pluto rotates on its axis C) 1609. B) twice each 6-hour day because Charon is in a retrograde D) 1781. orbit C) once every 2 days because Charon orbits in the same direction Pluto rotates but more slowly 5. -
Near-Infrared Observations of Active Asteroid (3200) Phaethon Reveal No Evidence for Hydration ✉ Driss Takir 1,7 , Theodore Kareta 2, Joshua P
ARTICLE https://doi.org/10.1038/s41467-020-15637-7 OPEN Near-infrared observations of active asteroid (3200) Phaethon reveal no evidence for hydration ✉ Driss Takir 1,7 , Theodore Kareta 2, Joshua P. Emery3, Josef Hanuš 4, Vishnu Reddy2, Ellen S. Howell2, Andrew S. Rivkin5 & Tomoko Arai6 Asteroid (3200) Phaethon is an active near-Earth asteroid and the parent body of the Geminid Meteor Shower. Because of its small perihelion distance, Phaethon’s surface reaches 1234567890():,; temperatures sufficient to destabilize hydrated materials. We conducted rotationally resolved spectroscopic observations of this asteroid, mostly covering the northern hemisphere and the equatorial region, beyond 2.5-µm to search for evidence of hydration on its surface. Here we show that the observed part of Phaethon does not exhibit the 3-µm hydrated mineral absorption (within 2σ). These observations suggest that Phaethon’s modern activity is not due to volatile sublimation or devolatilization of phyllosilicates on its surface. It is possible that the observed part of Phaethon was originally hydrated and has since lost volatiles from its surface via dehydration, supporting its connection to the Pallas family, or it was formed from anhydrous material. 1 JETS/ARES, NASA Johnson Space Center, Houston, TX 77058-3696, USA. 2 Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721- 0092, USA. 3 Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA. 4 Institute of Astronomy, Charles University, CZ-18000 Prague 8, Czech Republic. 5 Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20273, USA. 6 Planetary Exploration Research Center, Chiba Institute of Technology, Narashino, Japan.