DOCSLIB.ORG

The Minor Bodies of the Solar System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Minor Bodies of the Solar System CHAPTER ONE The Minor Bodies of the Solar System It is widely believed that about 4600 million years ago our solar system suffered a chain of disruptive events associated with condensation, intense heating, melting and eruptions, and that such events never occurred again with the same intensity. Throughout the remainder of cosmic history, the primary planetary and meteoric bodies are assumed to have cooled more or less homogeneously. Mutual collisions have increased their number and reduced their average size. On the other hand, through gravitational pull of the planets, a large number of the smaller bodies have already been eliminated in crater-producing events, while a few have been captured as satellites of the larger planets, Jupiter, Saturn, Uranus, Neptune and Mars. It is now well known that the larger bodies of our solar system, Earth, Mars and Moon, are scarred to a considerable degree by craters which on Earth are called astroblemes (Dietz 1963). The fact that the smaller bodies are also severely damaged, or perhaps are themselves fragments, was proved when in November 1971, the U.S. spacecraft Mariner 9 succeeded in relaying the frrst detailed views of any natural satellites in the solar system except the Moon. Photographed from a distance of 5500 km, Mars' two satellites, Phobos and Deimos, were found to be irregular, angular objects. The roughly potato shaped Phobos is 26 km long and 21 km wide and displays at least a dozen impact craters. The biggest depression, about 6 km across, probably indicates where a large fragment broke off during an asteroidal collision. The morphology of these tiny satellites not only suggests that they are very old but also Figure lA. The Lost City Fireball. A photograph taken at the Hominy, Oklahoma, camera station, operated by the Smithsonian that they possess considerable structural strength. Astrophysical Observatory, showing the spectacular meteor descend­ On January 3, 1970, at 2014 local time, a fireball ing the eastern sky on January 3, 1970. It remained visible for nine brighter then the full moon descended over Oklahoma and seconds as may be deduced from the series of dashes into which the trail was automatically broken by a chopping shutter. Star trails of caused sonic booms that were heard over a 100 km long Taurus, Orion, and Canis Major cross the background. (Courtesy zone below the line of flight. The fireball was photographed R.E. McCrosky.) by the Prairie Network and the analysis of the trajectory indicated that it had produced some sizable meteorites. A closely associated with the astronomical interpretation of careful search resulted in the recovery of four fragments of the orbits of meteoroids and minor planets of our solar a stone meteorite totaling 17 kg. The successful recovery system. The other is mainly concerned with the physical­ was immediately followed by extensive studies of the chemical study of meteoritic matter itself and with the mineralogy, chemistry, and isotope chemistry, with the solution of the problem of the origin of meteorites and the result that the Lost City meteorite is today perhaps our size of the parent bodies. A start will be made by examining best known from all points of view (McCrosky et a!. 1971; some basic aspects of the solar system. We will then turn to Clarke eta!. 1971b). the physics of the meteorite fall and eventually examine the The entire range of basic problems in meteoritics may fallen meteorite. Finally, in the main part of the handbook, be divided into two main parts. One comprises the study of the individual iron meteorites will be described in alpha­ the circumstances of meteorite falls on the Earth and is betical order. 6 The Minor Bodies of the Solar System This assumption proved to be correct. By 1800, 280 had been discovered and subsequently, after the introduc­ tion of the systematic photography of the skies, the number increased sharply. Today, 1779 are numbered (Ephemerides, Chebotarev, 1971) and accurate orbits have been calculated. There are in addition, however, a large number of smaller asteroids which usually have only been seen and identified once, at the time of their discovery. According to the recent extensive photographic survey conducted at the Palomar and Leiden observatories, the total number of asteroids that become brighter than photographic magnitude 20.4 at mean opposition is about 40,000; see Figure 2. The steady growth in numbers as that magnitude limit is approached makes it very likely that the sequence continues down to bodies as small as meteorites and dust grains. The great majority of the asteroids move in orbits which lie within the range of 2.1 to 3.5 A.U. from the Sun, so that the approximate average of 2.8 is in agreement with the requirement of Bode's rule. See Table 2. The orbital periods vary between 3.3 and 9 years, with an average of 4.5 years. Most eccentricities lie between 0.02 and 0.3, with an average of 0.15. The orbital inclinations range from 0° to 35° with an average of about 10°. They all move in their orbits in the same direction as the major planets, i.e., direct or counterclockwise. The large asteroids, such as Ceres, Pallas and Vesta, are nearly spherical, but many others have irregular, angular shapes suggesting that they are secondary collision frag­ ments. The angular shape is indicated by the large variation in brightness observed as the asteroid rotates and reflects sunlight from different regions on its surface. See Figure 3 I or McCord et al. (1970). From the fluctuations in bright­ Figure lB. Lost City (U.S.N.M. no. 4848). Reconstruction by Roy ness of Eros, for example (table 3), it has been estimated S. Clarke, Jr. of the mass. The 9.8 kg main mass was found on January 9th after analyzing the trail in Figure lA; three other that it measures about 24 x 8 x 8 km in three perpendicular masses were found Ia ter. Lost City is an olivine-bronzite chondrite directions. The masses of even the largest asteroids are too of a common type (H5), containing about 15% (by weight) small to be determined by conventional methods. Rough karnacite, 1.5% taenite, 6% troilite and 0.5% chrornite (Clarke eta!. 1971b; S.I. neg. 1636c.) Scale bar 5 ern. estimates based upon the observed, not too precise dimen­ sions, and on the assumption that the density is comparable Asteroids When comparing the orbits of the planets, there mooo~----------------------------------- 0 appears to be an exceptionally large gap separating Mars 0 o Palomar- Lei den 0 10000 0 and Jupiter. At an early date Kepler suggested that a planet 0 Vl • McDonald 0 might be found in this region of the solar system, and in 0 f:i1 0 1772 a German astronomer, J.E. Bode, publicized what has UJ 0 1- 1000 Vl later become known as Bode's rule (Jaki 1972). According <t • u. to this, the distances, in astronomical units (A.U.), of the 0 • • 0: • UJ m • • successive planets from the Sun are obtained by adding 0.4 ro • ::E • • to each of the following numbers: 0, 0.3, 0.6, 1.2, 2.4, 4.8, z::::> • etc.; see Table I. The discovery of Ceres, in 1801 , appeared 10 • • • to fill the gap in the system, but by 1807 three other • similar bodies (see Table 2) had been discovered with orbits • in the same region. These also happened to be the largest of 10 12 11. 16 18 20 all asteroids and their orbital elements are typical for the MEAN OPPOSITION MAGNITUDE majority of asteroids. Chladni (1819: 412) discussed the Figure 2. Each point represents the cumulative number of bodies in the entire asteroid ring. (Adapted from a diagram by C.J. van Hou­ then known four asteroids as possible sources of meteorites, ten in Astronomy and Astrophysics Supplement, Vol. 2, Springer and he expected more asteroids to be found. Verlag, 1970.) The Minor Bodies of the Solar System 7 3 to that of the Moon, 3.3 g per cm , leads to a figure of Earth-Sun Distance, the astronomical unit. Kepler and 7.6 x 10 17tons for Ceres, or about one percent of the mass Amor belong to a small family of asteroids with Mars­ of the Moon. The total mass of all asteroids is estimated to crossing orbits. Apollo , Hermes, Ikarus and Geographos are be about 3 x 10 18 tons (Putilin 1952). members of the Apollo family of eight asteroids with high Among the relatively few asteroids whose orbital eccentricities and Earth-crossing orbits. The Amor and characteristics are outside the range given above are a Apollo asteroids are very probably former normal asteroids number which have attracted special attention; see Table 3. which were perturbed into their present orbits by Mars. Hidalgo has the largest orbit known, almost touching the The known asteroids are no doubt accompanied by a orbit of Saturn. It was possibly deflected into its present huge number of smaller fragments not large enough to be orbit relatively recently as the result of a collision with observed from Earth. The 80 em telescope on board Skylab another minor planet (Marsden 1970). Eros was the first may, however, have a chance to identify some of the asteroid found to cross inside the orbit of Mars and use was smaller asteroids since the optical resolution is much made of this to calculate a much improved value for the improved outside our atmosphere. As the asteroidal orbits Table 1 - The Planets Planet Bode's Mean Eccen- Inclination Sidereal Diameter Mass Mean and date Rule distance tricity to ecliptic period, km tons density of discovery 1771 from Sun, years g/cm 3 A.U.
Load more

Recommended publications
  • CAPTURE of TRANS-NEPTUNIAN PLANETESIMALS in the MAIN ASTEROID BELT David Vokrouhlický1, William F
    The Astronomical Journal, 152:39 (20pp), 2016 August doi:10.3847/0004-6256/152/2/39 © 2016. The American Astronomical Society. All rights reserved. CAPTURE OF TRANS-NEPTUNIAN PLANETESIMALS IN THE MAIN ASTEROID BELT David Vokrouhlický1, William F. Bottke2, and David Nesvorný2 1 Institute of Astronomy, Charles University, V Holešovičkách 2, CZ–18000 Prague 8, Czech Republic; [email protected] 2 Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302; [email protected], [email protected] Received 2016 February 9; accepted 2016 April 21; published 2016 July 26 ABSTRACT The orbital evolution of the giant planets after nebular gas was eliminated from the Solar System but before the planets reached their final configuration was driven by interactions with a vast sea of leftover planetesimals. Several variants of planetary migration with this kind of system architecture have been proposed. Here, we focus on a highly successful case, which assumes that there were once five planets in the outer Solar System in a stable configuration: Jupiter, Saturn, Uranus, Neptune, and a Neptune-like body. Beyond these planets existed a primordial disk containing thousands of Pluto-sized bodies, ∼50 million D > 100 km bodies, and a multitude of smaller bodies. This system eventually went through a dynamical instability that scattered the planetesimals and allowed the planets to encounter one another. The extra Neptune-like body was ejected via a Jupiter encounter, but not before it helped to populate stable niches with disk planetesimals across the Solar System. Here, we investigate how interactions between the fifth giant planet, Jupiter, and disk planetesimals helped to capture disk planetesimals into both the asteroid belt and first-order mean-motion resonances with Jupiter.
    [Show full text]
  • Uhm Ms 3980 R.Pdf
    UNIVERSITY OF HAWAI'I LIBRARY The Enigmatic Surface of(3200) Phaethon: Comparison with cometary candidates A THESIS SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI'I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN ASTRONOMY August 2005 By Luke R. Dundon Thesis Committee: K. Meech, Chairperson S. Bus D. Tholen To my parents, David and Colleen Dundon. III Acknowledgments lowe much gratitude to my advisor, Karen Meech, as well as the other members of my thesis committee, Dave Tholen and Bobby Bus. Karen, among many other things, trained me in the art of data reduction and good observing technique, as well as successful writing of telescope proposals. Bobby helped me perform productive near-IR spectral observation and subsequent data reduction. Dave provided keen analytical insight throughout the entire process of my project. With the tremendous guidance, expertise and advice of my committee, I was able to complete this project. They were always willing to aid me through my most difficult dilemmas. This work would not have been possible without their help. Thanks is also due to numerous people at the !fA who have helped me through my project in various ways. Dave Jewitt was always available to offer practical scientific advice, as well as numerous data reduction strategies. Van Fernandez allowed me to use a few of his numerous IDL programs for lightcurve analysis and spectral reduction. His advice was also quite insightful and helped focus my own thought processes. Jana Pittichova guided me through the initial stages of learning how to observe, which was crucial for my successful observations of (3200) Phaethon in the Fall of 2004.
    [Show full text]
  • The Relationship Between Centaurs and Jupiter Family Comets with Implications for K-Pg-Type Impacts K
    1 The Relationship between Centaurs and Jupiter Family Comets with Implications for K-Pg-type Impacts K. R. Grazier1*†, J. Horner2, J. C. Castillo-Rogez3 1United States Military Academy, West Point, NY, United States 2Centre for Astrophysics, University of Southern Queensland, Toowoomba, Queensland 4350, Australia 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States. *Corresponding Author. E-mail: [email protected] †Now at NASA/Marshall Space Flight Center, Huntsville, AL, United States Centaurs—icy bodies orbiting beyond Jupiter and interior to Neptune—are believed to be dynamically related to Jupiter Family Comets (JFCs), which have aphelia near Jupiter’s orbit, and perihelia in the inner Solar System. Previous dynamical simulations have recreated the Centaur/JFC conversion, but the mechanism behind that process remains poorly described. We have performed a numerical simulation of Centaur analogues that recreates this process, generating a dataset detailing over 2.6 million close planet/planetesimal interactions. We explore scenarios stored within that database and, from those, describe the mechanism by which Centaur objects are converted into JFCs. Because many JFCs have perihelia in the terrestrial planet region, and since Centaurs are constantly resupplied from the Scattered Disk and other reservoirs, the JFCs are an ever-present impact threat. Keywords: dynamical evolution and stability, celestial mechanics, comets, asteroids 1. Introduction Over the past decade, a number of studies have brought into question the long-held belief that Jupiter acts to shield the Earth from comet impacts. The work of Wetherill (1994, 1995), who studied the influence of the giant planets in clearing debris from the outer Solar System, is often heralded as the source of the “Jupiter: the Shield” paradigm, and was one of the core tenets of the Rare Earth hypothesis of Ward & Brownlee (2000) who popularized the notion.
    [Show full text]
  • Disk-Resolved Optical Spectra of Near-Earth Asteroid 25143 Itokawa with Hayabusa/AMICA Observations
    발표논문 초록 (태양계) [구SS-01] Disk-Resolved Optical Spectra of Near-Earth Asteroid 25143 Itokawa with Hayabusa/AMICA observations Masateru Ishiguro Seoul National University The Hayabusa mission successfully rendezvoused with its target asteroid 25143 Itokawa in 2005 and brought the asteroidal sample to the Earth in 2009. This mission enabled to connect the S-type asteroids to ordinary chondrites, the counterpart meteorites which exist in near Earth orbit. Recent finding of a fragment from 25143 Itokawa [1] suggested that the asteroid experienced an impact after the injection to the near-Earth orbit. In this presentation, we investigated the evidence of the recent impact on 25143 Itokawa using the onboard camera, AMICA. AMICA took more than 1400 images of Itokawa during the rendezvous phase. It is reported that AMICA images are highly contaminated by lights scattered inside the optics in the longer wavelength. We developed a technique to subtract the scattered light by determining the point spread functions for all available channels. As the result, we first succeeded in the determination of the surface spectra in all available bands. We consider a most fresh-looking compact crater, Kamoi, is a possible impact site. [1] Ohtsuka, K., Publications of the Astronomical Society of Japan, 63, 6, L73-L77 [구SS-02] Dynamical Evolution of the Dark Asteroids with Tisserand parameter 김윤영1, Masateru Ishiguro2, 정진훈2, 양홍규2, Fumihiko Usui3 1 이화여자대학교 물리학과, 2서울대학교 물리천문학부, 3우주과학연구소 (일본) It has been speculated that there could be dormant or extinct comets in the list of known asteroids, which appear asteroidal but are icy bodies originating from outer solar system.
    [Show full text]
  • Orbital Shapes of Asteroids in Cometary Orbits Based on 0.7M Telescope Imaging
    Orbital Shapes of Asteroids in Cometary Orbits based on 0.7m Telescope Imaging 1,2,3 2,3 S Dueantakhu , S Wannawichian 1 Graduate School, Chiang Mai University, Chiang Mai, Thailand 2 Department of physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand 3 National Astronomical Research Institute of Thailand(NARIT), Chiang Mai, Thailand E-mail: [email protected] Abstract. The study of orbital elements of Asteroids in Cometary Orbits (ACOs) is based on images taken by a 0.7-m telescope to find positions of asteroids and calculate their orbital elements. This work focuses on variation of positions and orbital shape of an asteroid, 1667Pels, which is obtained by analyzing orbital elements and minimum orbital intersection distances. Each observation, those parameters are affected by the gravity from Jupiter on ACOs. The accuracy of single site data was calibrated by comparing the result from this work to other observations in Minor Planet Center database. 1. Introduction Asteroids are members of minor planet group. Some of their movements are affected by giant planets, especially Jupiter, which make orbits of asteroids highly variable. The three-body problem is the major case for discussion about position of planet and its satellite. For asteroid, it is a special case that is called restricted three-body problem [3] because it has infinitesimal mass and moves in the gravitational field of the sun and giant planets. Solution of restricted three-body problem is [3] " " " "(()*) "* � = � + � + + − � (1) , , - . Where � is the speed of the infinitesimal mass. � and � are position of the mass. �(and �" are positioning vectors of the mass, � is mass of secondary body and 1 − � is mass of primary body � is Jacobi's integral parameter, � is a planet and 1 − � is the Sun.
    [Show full text]
  • Appendix 1 1311 Discoverers in Alphabetical Order
    Appendix 1 1311 Discoverers in Alphabetical Order Abe, H. 28 (8) 1993-1999 Bernstein, G. 1 1998 Abe, M. 1 (1) 1994 Bettelheim, E. 1 (1) 2000 Abraham, M. 3 (3) 1999 Bickel, W. 443 1995-2010 Aikman, G. C. L. 4 1994-1998 Biggs, J. 1 2001 Akiyama, M. 16 (10) 1989-1999 Bigourdan, G. 1 1894 Albitskij, V. A. 10 1923-1925 Billings, G. W. 6 1999 Aldering, G. 4 1982 Binzel, R. P. 3 1987-1990 Alikoski, H. 13 1938-1953 Birkle, K. 8 (8) 1989-1993 Allen, E. J. 1 2004 Birtwhistle, P. 56 2003-2009 Allen, L. 2 2004 Blasco, M. 5 (1) 1996-2000 Alu, J. 24 (13) 1987-1993 Block, A. 1 2000 Amburgey, L. L. 2 1997-2000 Boattini, A. 237 (224) 1977-2006 Andrews, A. D. 1 1965 Boehnhardt, H. 1 (1) 1993 Antal, M. 17 1971-1988 Boeker, A. 1 (1) 2002 Antolini, P. 4 (3) 1994-1996 Boeuf, M. 12 1998-2000 Antonini, P. 35 1997-1999 Boffin, H. M. J. 10 (2) 1999-2001 Aoki, M. 2 1996-1997 Bohrmann, A. 9 1936-1938 Apitzsch, R. 43 2004-2009 Boles, T. 1 2002 Arai, M. 45 (45) 1988-1991 Bonomi, R. 1 (1) 1995 Araki, H. 2 (2) 1994 Borgman, D. 1 (1) 2004 Arend, S. 51 1929-1961 B¨orngen, F. 535 (231) 1961-1995 Armstrong, C. 1 (1) 1997 Borrelly, A. 19 1866-1894 Armstrong, M. 2 (1) 1997-1998 Bourban, G. 1 (1) 2005 Asami, A. 7 1997-1999 Bourgeois, P. 1 1929 Asher, D.
    [Show full text]
  • The Minor Planet Bulletin, It Is a Pleasure to Announce the Appointment of Brian D
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 33, NUMBER 1, A.D. 2006 JANUARY-MARCH 1. LIGHTCURVE AND ROTATION PERIOD Observatory (Observatory code 926) near Nogales, Arizona. The DETERMINATION FOR MINOR PLANET 4006 SANDLER observatory is located at an altitude of 1312 meters and features a 0.81 m F7 Ritchey-Chrétien telescope and a SITe 1024 x 1024 x Matthew T. Vonk 24 micron CCD. Observations were conducted on (UT dates) Daniel J. Kopchinski January 29, February 7, 8, 2005. A total of 37 unfiltered images Amanda R. Pittman with exposure times of 120 seconds were analyzed using Canopus. Stephen Taubel The lightcurve, shown in the figure below, indicates a period of Department of Physics 3.40 ± 0.01 hours and an amplitude of 0.16 magnitude. University of Wisconsin – River Falls 410 South Third Street Acknowledgements River Falls, WI 54022 [email protected] Thanks to Michael Schwartz and Paulo Halvorcem for their great work at Tenagra Observatory. (Received: 25 July) References Minor planet 4006 Sandler was observed during January Schmadel, L. D. (1999). Dictionary of Minor Planet Names. and February of 2005. The synodic period was Springer: Berlin, Germany. 4th Edition. measured and determined to be 3.40 ± 0.01 hours with an amplitude of 0.16 magnitude. Warner, B. D. and Alan Harris, A. (2004) “Potential Lightcurve Targets 2005 January – March”, www.minorplanetobserver.com/ astlc/targets_1q_2005.htm Minor planet 4006 Sandler was discovered by the Russian astronomer Tamara Mikhailovna Smirnova in 1972. (Schmadel, 1999) It orbits the sun with an orbit that varies between 2.058 AU and 2.975 AU which locates it in the heart of the main asteroid belt.
    [Show full text]
  • Prediction of Water in Asteroids from Spectral Data Shortward of 3 Ȑm
    ICARUS 129, 421±439 (1997) ARTICLE NO. IS975796 Prediction of Water in Asteroids from Spectral Data Shortward of 3 em ErzseÂbet MereÂnyi1 Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721 E-mail: [email protected] Ellen S. Howell Department of Geology, University of Puerto Rico, ManaguÈez, Puerto Rico 00681-5000 and Andrew S. Rivkin and Larry A. Lebofsky Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721 Received May 22, 1996; revised May 12, 1997 spectral features shortward of 3 em. If such associated Spectra of many asteroids display a 3 mm absorption feature features are detected, then it may be possible to construct that has been associated with the presence of water of hydration a tool with which the presence of a 3 em water band could in clays or hydrated salts. Detection of this feature, however, be predicted from shorter wavelength observations, with is dif®cult through the Earth's atmosphere for various reasons. high probability. Due to low ¯ux levels and terrestrial Correlations were sought and detected between the 3 mm ab- absorption it is often dif®cult to detect the presence of sorption band and features shortward of 3 mm, which enabled the 3 em water band. Prediction capability using shorter- us to construct a tool for the prediction of water in asteroids wavelength data would allow us to more easily obtain ob- from the shorter wavelength part of the spectrum. Such a pre- diction tool can help concentrate observing resources to those servations and enable the economization of the 3 em band objects most likely to have water.
    [Show full text]
  • 42. the MOTION of HIDALGO and the MASS of SATURN Unusual Though the Orbits of Many of the Minor Planets May Be, None Is So Anoma
    42. THE MOTION OF HIDALGO AND THE MASS OF SATURN B. G. MARSDEN Smithsonian Astrophysical Observatory, Cambridge, Mass., U.S.A. Abstract. The principal features of the motion of Hidalgo over the interval 1400-2900 are described. The possibility that this object is an extinct (or nearly extinct) comet nucleus is discussed. A determination of the mass of Saturn, using observations of Hidalgo during 1920-1964, is presented and compared with other recent determinations. Unusual though the orbits of many of the minor planets may be, none is so anomalous in so many different ways as that of 944 Hidalgo. In many respects the orbit of Hidalgo represents a compromise among those of the periodic comets Tuttle, Wild, and Neuj- min 1, all four objects having their aphelia near the orbit of Saturn and rather high orbital eccentricities and inclinations. Perhaps the most significant difference between minor planets and short-period comets is that the orbits of the latter are continually being disturbed as the result of passages near Jupiter, while the orbits of the former - except for Hidalgo - are stable. That Hidalgo can pass only 0.4 AU from Jupiter (Belyaev and Chebotarev, 1968) can certainly be regarded as suggestive of its cometary nature. Actually, the orbit of Hidalgo would be relatively stable for a short-period comet, only P/Neujmin 1 and P/Arend-Rigaux having been more successful at avoiding Jupiter in recent cen­ turies (Marsden, 1970). These two comets are unusual in that they are almost invari­ ably asteroidal in appearance, their cometary character having been evident only when they were considerably closer to the Earth than Hidalgo ever comes.
    [Show full text]
  • The Minor Planet Bulletin Is Open to Papers on All Aspects of 6500 Kodaira (F) 9 25.5 14.8 + 5 0 Minor Planet Study
    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 32, NUMBER 3, A.D. 2005 JULY-SEPTEMBER 45. 120 LACHESIS – A VERY SLOW ROTATOR were light-time corrected. Aspect data are listed in Table I, which also shows the (small) percentage of the lightcurve observed each Colin Bembrick night, due to the long period. Period analysis was carried out Mt Tarana Observatory using the “AVE” software (Barbera, 2004). Initial results indicated PO Box 1537, Bathurst, NSW, Australia a period close to 1.95 days and many trial phase stacks further [email protected] refined this to 1.910 days. The composite light curve is shown in Figure 1, where the assumption has been made that the two Bill Allen maxima are of approximately equal brightness. The arbitrary zero Vintage Lane Observatory phase maximum is at JD 2453077.240. 83 Vintage Lane, RD3, Blenheim, New Zealand Due to the long period, even nine nights of observations over two (Received: 17 January Revised: 12 May) weeks (less than 8 rotations) have not enabled us to cover the full phase curve. The period of 45.84 hours is the best fit to the current Minor planet 120 Lachesis appears to belong to the data. Further refinement of the period will require (probably) a group of slow rotators, with a synodic period of 45.84 ± combined effort by multiple observers – preferably at several 0.07 hours. The amplitude of the lightcurve at this longitudes. Asteroids of this size commonly have rotation rates of opposition was just over 0.2 magnitudes.
    [Show full text]
  • Added-Value Interfaces to Asteroid Photometric and Spectroscopic Data in the Gaia Database
    Accepted Manuscript Added-value interfaces to asteroid photometric and spectroscopic data in the Gaia database Johanna Torppa, Mikael Granvik, Antti Penttilä, Jukka Reitmaa, Violeta Tudose, Leena Pelttari, Karri Muinonen, Jorgo Bakker, Vicente Navarro, William O’Mullane PII: S0273-1177(18)30367-3 DOI: https://doi.org/10.1016/j.asr.2018.04.035 Reference: JASR 13736 To appear in: Advances in Space Research Received Date: 9 February 2018 Accepted Date: 22 April 2018 Please cite this article as: Torppa, J., Granvik, M., Penttilä, A., Reitmaa, J., Tudose, V., Pelttari, L., Muinonen, K., Bakker, J., Navarro, V., O’Mullane, W., Added-value interfaces to asteroid photometric and spectroscopic data in the Gaia database, Advances in Space Research (2018), doi: https://doi.org/10.1016/j.asr.2018.04.035 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Added-value interfaces to asteroid photometric and spectroscopic data in the Gaia database Johanna Torppaa,˚, Mikael Granvikb,d, Antti Penttiläb, Jukka Reitmaaa, Violeta Tudosea, Leena Pelttaria, Karri Muinonenb, Jorgo Bakkerc, Vicente Navarroc, William O’Mullanec aSpace Systems Finland, Kappelitie 6 B, 02200 Espoo, Finland. Emails: [email protected], [email protected], violeta.tudose@ssf.fi, marja-leena.pelttari@ssf.fi bDepartment of Physics, P.O.
    [Show full text]
  • Nasa Technical Memorandum .1
    NASA TECHNICAL MEMORANDUM NASA TM X-64677 COMETS AND ASTEROIDS: A Strategy for Exploration REPORT OF THE COMET AND ASTEROID MISSION STUDY PANEL May 1972 .1!vP -V (NASA-TE-X- 6 q767 ) COMETS AND ASTEROIDS: A RR EXPLORATION (NASA) May 1972 CSCL 03A NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Reproduced by ' NATIONAL "TECHINICAL INFORMATION: SERVICE US Depdrtmett ofCommerce :. Springfield VA 22151 TECHNICAL REPORT STANDARD TITLE PAGE · REPORT NO. 2. GOVERNMENT ACCESSION NO. 3, RECIPIENT'S CATALOG NO. NASA TM X-64677 . TITLE AND SUBTITLE 5. REPORT aE COMETS AND ASTEROIDS ___1_ A Strategy for Exploration 6. PERFORMING ORGANIZATION CODE AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT # Comet and Asteroid Mission Study Panel PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NO. 11. CONTRACT OR GRANT NO. 13. TYPE OF REPORT & PERIOD COVERED 2. SPONSORING AGENCY NAME AND ADDRESS National Aeronautics and Space Administration Technical Memorandum Washington, D. C. 20546 14. SPONSORING AGENCY CODE 5. SUPPLEMENTARY NOTES ABSTRACT Many of the asteroids probably formed near the orbits where they are found today. They accreted from gases and particles that represented the primordial solar system cloud at that location. Comets, in contrast to asteroids, probably formed far out in the solar system, and at very low temperatures; since they have retained their volatile components they are probably the most primordial matter that presently can be found anywhere in the solar system. Exploration and detailed study of comets and asteroids, therefore, should be a significant part of NASA's efforts to understand the solar system. A comet and asteroid program should consist of six major types of projects: ground-based observations;Earth-orbital observations; flybys; rendezvous; landings; and sample returns.
    [Show full text]