The Compositional Structure of the Asteroid Belt
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Dynamical Evolution of the Hungaria Asteroids ⇑ Firth M
Icarus 210 (2010) 644–654 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Dynamical evolution of the Hungaria asteroids ⇑ Firth M. McEachern, Matija C´ uk , Sarah T. Stewart Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA article info abstract Article history: The Hungarias are a stable asteroid group orbiting between Mars and the main asteroid belt, with high Received 29 June 2009 inclinations (16–30°), low eccentricities (e < 0.18), and a narrow range of semi-major axes (1.78– Revised 2 August 2010 2.06 AU). In order to explore the significance of thermally-induced Yarkovsky drift on the population, Accepted 7 August 2010 we conducted three orbital simulations of a 1000-particle grid in Hungaria a–e–i space. The three simu- Available online 14 August 2010 lations included asteroid radii of 0.2, 1.0, and 5.0 km, respectively, with run times of 200 Myr. The results show that mean motion resonances—martian ones in particular—play a significant role in the destabili- Keywords: zation of asteroids in the region. We conclude that either the initial Hungaria population was enormous, Asteroids or, more likely, Hungarias must be replenished through collisional or dynamical means. To test the latter Asteroids, Dynamics Resonances, Orbital possibility, we conducted three more simulations of the same radii, this time in nearby Mars-crossing space. We find that certain Mars crossers can be trapped in martian resonances, and by a combination of chaotic diffusion and the Yarkovsky effect, can be stabilized by them. -
Meteorites, Asteroids, and Comets
Space Sci Rev (2018) 214:36 https://doi.org/10.1007/s11214-018-0474-9 Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets Conel M.O’D. Alexander1 · Kevin D. McKeegan2 · Kathrin Altwegg3 Received: 10 January 2018 / Accepted: 11 January 2018 / Published online: 23 January 2018 © Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract Asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. They are also likely the sources of most of the water and other volatiles accreted by Earth. In this review, we discuss the nature and probable origins of asteroids and comets based on data from remote observations, in situ measurements by spacecraft, and laboratory analyses of meteorites derived from asteroids. The asteroidal par- ent bodies of meteorites formed ≤ 4 Ma after Solar System formation while there was still a gas disk present. It seems increasingly likely that the parent bodies of meteorites spectro- scopically linked with the E-, S-, M- and V-type asteroids formed sunward of Jupiter’s orbit, while those associated with C- and, possibly, D-type asteroids formed further out, beyond Jupiter but probably not beyond Saturn’s orbit. Comets formed further from the Sun than any of the meteorite parent bodies, and retain much higher abundances of interstellar mate- rial. CI and CM group meteorites are probably related to the most common C-type asteroids, and based on isotopic evidence they, rather than comets, are the most likely sources of the H and N accreted by the terrestrial planets. -
The Hungaria Asteroids: Close Encounters and Impacts with Terrestrial Planets
Mem. S.A.It. Suppl. Vol. 26, 38 Memorie della c SAIt 2014 Supplementi The Hungaria Asteroids: close encounters and impacts with terrestrial planets M. A. Galiazzo, A. Bazso, and R. Dvorak Institute of Astronomy, University of Vienna, Turkenschanzstr.¨ 17, A-1180 Wien, Austria e-mail: [email protected] Abstract. The Hungaria asteroid family (Named after (434) Hungaria), which consists of more than 5000 members with semi-major axes between 1.78 and 2.03 AU and have in- clinations of the order of 20◦, is regarded as one source for Near-Earth Asteroids (NEAs). They are mainly perturbed by Jupiter and Mars, and are ejected because of mean motion and secular resonances with these planets and then become Mars-crossers; later they may even cross the orbits of Earth and Venus. We are interested to analyze the close encounters and possible impacts with these planets. For 200 selected objects which are on the edge of the group we integrated their orbits over 100 million years in a simplified model of the planetary system (Mars to Saturn) subject to only gravitational forces. We picked out a sam- ple of 11 objects (each with 50 clones) with large variations in semi-major axis and some of them achieve high inclinations and eccentricities in connection with mean motion and secular resonances which then leads to relatively high velocity impacts on Venus, Earth and Mars. We report all close encounters and impacts with the terrestrial planets and statistically determine the mean life and the orbital distribution of the NEAs of these Hungarias. -
The Recent Breakup of an Asteroid in the Main-Belt Region
letters to nature .............................................................. (see Methods section). The recent breakup of an asteroid in The orbital distribution of the 39-body cluster is diagonally shaped in (a P, e P), and appears to fit inside one of the similarly the main-belt region shaped ‘equivelocity’ ellipses shown in Fig. 1. To create these ellipses, we launched test bodies isotropically from the centre of David Nesvorny´, William F. Bottke Jr, Luke Dones & Harold F. Levison the cluster (presumably the impact site) at a selected velocity impulse dV. Using Gauss’s equations (see, for example, ref. 14), Southwest Research Institute, 1050 Walnut St, Suite 426, Boulder, Colorado we then computed the change in their proper elements (da P, de P, 80302, USA diP). To determine the size, shape and orientation of the ellipses, we ............................................................................................................................................................................. experimented with various values of Vmax, the maximum velocity The present population of asteroids in the main belt is largely the 1,2 among our test bodies, the true anomaly f of the parent body (that result of many past collisions . Ideally, the asteroid fragments is, the angle between the parent body’s location and the perihelion resulting from each impact event could help us understand the of its orbit) and the parent body’s perihelion argument q at the large-scale collisions that shaped the planets during early instant of the impact (that is, the angle between the perihelion and epochs3–5. Most known asteroid fragment families, however, are the ascending node). very old and have therefore undergone significant collisional and We found that ellipsoids having V < 15 m s21, dynamical evolution since their formation6. -
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. -
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. -
The Solar System
5 The Solar System R. Lynne Jones, Steven R. Chesley, Paul A. Abell, Michael E. Brown, Josef Durech,ˇ Yanga R. Fern´andez,Alan W. Harris, Matt J. Holman, Zeljkoˇ Ivezi´c,R. Jedicke, Mikko Kaasalainen, Nathan A. Kaib, Zoran Kneˇzevi´c,Andrea Milani, Alex Parker, Stephen T. Ridgway, David E. Trilling, Bojan Vrˇsnak LSST will provide huge advances in our knowledge of millions of astronomical objects “close to home’”– the small bodies in our Solar System. Previous studies of these small bodies have led to dramatic changes in our understanding of the process of planet formation and evolution, and the relationship between our Solar System and other systems. Beyond providing asteroid targets for space missions or igniting popular interest in observing a new comet or learning about a new distant icy dwarf planet, these small bodies also serve as large populations of “test particles,” recording the dynamical history of the giant planets, revealing the nature of the Solar System impactor population over time, and illustrating the size distributions of planetesimals, which were the building blocks of planets. In this chapter, a brief introduction to the different populations of small bodies in the Solar System (§ 5.1) is followed by a summary of the number of objects of each population that LSST is expected to find (§ 5.2). Some of the Solar System science that LSST will address is presented through the rest of the chapter, starting with the insights into planetary formation and evolution gained through the small body population orbital distributions (§ 5.3). The effects of collisional evolution in the Main Belt and Kuiper Belt are discussed in the next two sections, along with the implications for the determination of the size distribution in the Main Belt (§ 5.4) and possibilities for identifying wide binaries and understanding the environment in the early outer Solar System in § 5.5. -
Problems of Planetology, Cosmochemistry and Meteoritica Alexeev V.A., Ustinova G.K
Problems of Planetology… Problems of Planetology, Cosmochemistry and Meteoritica Alexeev V.A., Ustinova G.K. Meteoritic evidence radionuclides before the meteorite fall onto the Earth. The investigation of radionuclides with different T1/2 in the on peculiarities of the contemporary solar cycles chondrites with various dates of fall, which have various V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry extension and inclination of orbits, provides us with such RAS, Moscow long sequences of homogeneous data on variation of the Abstract. The meteorite data on monitoring of the intensity and GCR intensity and integral gradients (E >100 MeV) in the gradient of the galactic cosmic rays (GCR) in the heliosphere 3D heliosphere [Lavrukhina,Ustinova,1990]. The long during 5 solar cycles are used for the correlative analysis with the sequences of homogeneous data on the GCR intensity in variations of the solar activity (SA), strength of the interplanetary magnetic field (IMF) and tilt angle of the heliospheric current the stratosphere [Stozhkov et al., 2009] are used for sheet (HCS). The dependence of the GCR modulation depth in the evaluation of the gradients. Nowadays, such a sequence of 11-year solar cycles on the character of the solar magnetic field certain homogeneous data on the GCR intensity and (SMF) inversions in the heliosphere at the change of the 22-year gradients in the inner heliosphere covers ~5 solar cycles magnetic cycles is revealed. (see figure 1) [Alexeev, Ustinova, 2006]. This smoothes, Key words: galactic cosmic rays, solar modulation, solar cycles, to a considerable extent, both the temporal and spatial inversion of magnetic field, solar dynamo, climate. -
Lost Lake by Robert Verish
Meteorite-Times Magazine Contents by Editor Like Sign Up to see what your friends like. Featured Monthly Articles Accretion Desk by Martin Horejsi Jim’s Fragments by Jim Tobin Meteorite Market Trends by Michael Blood Bob’s Findings by Robert Verish IMCA Insights by The IMCA Team Micro Visions by John Kashuba Galactic Lore by Mike Gilmer Meteorite Calendar by Anne Black Meteorite of the Month by Michael Johnson Tektite of the Month by Editor Terms Of Use Materials contained in and linked to from this website do not necessarily reflect the views or opinions of The Meteorite Exchange, Inc., nor those of any person connected therewith. In no event shall The Meteorite Exchange, Inc. be responsible for, nor liable for, exposure to any such material in any form by any person or persons, whether written, graphic, audio or otherwise, presented on this or by any other website, web page or other cyber location linked to from this website. The Meteorite Exchange, Inc. does not endorse, edit nor hold any copyright interest in any material found on any website, web page or other cyber location linked to from this website. The Meteorite Exchange, Inc. shall not be held liable for any misinformation by any author, dealer and or seller. In no event will The Meteorite Exchange, Inc. be liable for any damages, including any loss of profits, lost savings, or any other commercial damage, including but not limited to special, consequential, or other damages arising out of this service. © Copyright 2002–2010 The Meteorite Exchange, Inc. All rights reserved. No reproduction of copyrighted material is allowed by any means without prior written permission of the copyright owner. -
Jjmonl 1710.Pmd
alactic Observer John J. McCarthy Observatory G Volume 10, No. 10 October 2017 The Last Waltz Cassini’s final mission and dance of death with Saturn more on page 4 and 20 The John J. McCarthy Observatory Galactic Observer New Milford High School Editorial Committee 388 Danbury Road Managing Editor New Milford, CT 06776 Bill Cloutier Phone/Voice: (860) 210-4117 Production & Design Phone/Fax: (860) 354-1595 www.mccarthyobservatory.org Allan Ostergren Website Development JJMO Staff Marc Polansky Technical Support It is through their efforts that the McCarthy Observatory Bob Lambert has established itself as a significant educational and recreational resource within the western Connecticut Dr. Parker Moreland community. Steve Barone Jim Johnstone Colin Campbell Carly KleinStern Dennis Cartolano Bob Lambert Route Mike Chiarella Roger Moore Jeff Chodak Parker Moreland, PhD Bill Cloutier Allan Ostergren Doug Delisle Marc Polansky Cecilia Detrich Joe Privitera Dirk Feather Monty Robson Randy Fender Don Ross Louise Gagnon Gene Schilling John Gebauer Katie Shusdock Elaine Green Paul Woodell Tina Hartzell Amy Ziffer In This Issue INTERNATIONAL OBSERVE THE MOON NIGHT ...................... 4 SOLAR ACTIVITY ........................................................... 19 MONTE APENNINES AND APOLLO 15 .................................. 5 COMMONLY USED TERMS ............................................... 19 FAREWELL TO RING WORLD ............................................ 5 FRONT PAGE ............................................................... -
Color Study of Asteroid Families Within the MOVIS Catalog David Morate1,2, Javier Licandro1,2, Marcel Popescu1,2,3, and Julia De León1,2
A&A 617, A72 (2018) Astronomy https://doi.org/10.1051/0004-6361/201832780 & © ESO 2018 Astrophysics Color study of asteroid families within the MOVIS catalog David Morate1,2, Javier Licandro1,2, Marcel Popescu1,2,3, and Julia de León1,2 1 Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n, 38205 La Laguna, Tenerife, Spain e-mail: [email protected] 2 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain 3 Astronomical Institute of the Romanian Academy, 5 Cu¸titulde Argint, 040557 Bucharest, Romania Received 6 February 2018 / Accepted 13 March 2018 ABSTRACT The aim of this work is to study the compositional diversity of asteroid families based on their near-infrared colors, using the data within the MOVIS catalog. As of 2017, this catalog presents data for 53 436 asteroids observed in at least two near-infrared filters (Y, J, H, or Ks). Among these asteroids, we find information for 6299 belonging to collisional families with both Y J and J Ks colors defined. The work presented here complements the data from SDSS and NEOWISE, and allows a detailed description− of− the overall composition of asteroid families. We derived a near-infrared parameter, the ML∗, that allows us to distinguish between four generic compositions: two different primitive groups (P1 and P2), a rocky population, and basaltic asteroids. We conducted statistical tests comparing the families in the MOVIS catalog with the theoretical distributions derived from our ML∗ in order to classify them according to the above-mentioned groups. We also studied the background populations in order to check how similar they are to their associated families. -
Dealing with the Threat of an Asteroid Striking the Earth
Dealing with the Threat of an Asteroid Striking the Earth An AIAA Position Paper April 1990 This paper originated in the AIAA Space Systems Technical Committee and was Approved by the AIAA Board of Directors American Institute of Aeronautics and Astronautics 1801 Alexander Bell Drive Reston, VA 20191 703/264-7500 SUMMARY Hundreds, perhaps thousands, of asteroids travel in orbits that intersect the Earth’s orbit. Some have struck the Earth in the past, leaving large craters. Others have come very close, one as recently as March 23, 1989 (Apollo Asteroid 1989FC, estimated to be a fifth to a half mile in diameter). Such an object, if it struck the Earth today, could cause a disaster of unprecedented proportions. Although the probability of such an occurrence is very small, its consequences (i.e., the casualty rate) could be enormous. The risk to Earth’s inhabitants is therefore finite, warranting action to improve and expand our ability to detect Earth- orbit-crossing objects and to analyze and predict their orbits. It would also be useful to explore methods and technologies for deflecting or destroying any such objects that are predicted to impact the Earth and to alter their orbits sufficiently to preclude impact. To begin the process of implementing such action, appropriate experts, both civil and military, should be tasked to formulate specific programs designed to address the issues involved. INTRODUCTION On March 23, 1989, an asteroid bigger than an aircraft carrier, traveling at 46,000 miles per hour, passed through Earth's orbit less than 400,000 miles away. Our planet had been at that point only six hours earlier.