Uranus, Neptune, Pluto, and the Outer Solar System Linda T

Total Page:16

File Type:pdf, Size:1020Kb

Uranus, Neptune, Pluto, and the Outer Solar System Linda T Uranus, Neptune, Pluto, and the Outer Solar System Linda T. Elkins-Tanton Uranus, Neptune, Pluto, and the Outer Solar System Copyright © 2006 by Linda T.Elkins-Tanton All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechani- cal, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 Library of Congress Cataloging-in-Publication Data Elkins-Tanton, Linda T. Uranus, Neptune, Pluto, and the outer solar system / Linda T.Elkins-Tanton. p. cm. — (The Solar system) Includes bibliographical references and index. ISBN 0-8160-5197-6 (acid-free paper) 1. Uranus (Planet)—Popular works. 2. Neptune (Planet)—Popular works. 3. Pluto (Planet)—Popular works. 4. Solar system—Popular works. I.Title. QB681.E45 2006 523.47—dc22 2005014801 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institu- tions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Text and cover design by Dorothy M. Preston Illustrations by Richard Garratt Printed in the United States of America VB Hermitage 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. In memory of my brother Thomas Turner Elkins, who, when I was 10 years old, taught me about the Oort cloud, and together we named our pet mouse Oort. Contents Preface . .ix Acknowledgments . .xv Introduction . .xvii PART ONE: URANUS AND NEPTUNE 1. Uranus: Fast Facts about a Planet in Orbit . .3 Fundamental Information about Uranus . .7 What Makes Gravity? . .10 2. The Interior of Uranus . .13 Composition . .13 What Is Pressure? . .15 Internal Temperatures . .17 Elements and Isotopes . .18 Magnetic Field . .20 3. Surface Appearance and Conditions on Uranus . .23 Remote Sensing . .26 4. Rings and Moons of Uranus . .37 Rings . .37 Moons . .39 Why Are There Rings? . .42 Accretion and Heating:Why Are Some Solar System Objects Round and Others Irregular? . .45 What Are Synchronous Orbits and Synchronous Rotation? . .51 5. Neptune: Fast Facts about a Planet in Orbit . .63 Fundamental Information about Neptune . .65 6. The Interior of Neptune . .75 Sabine Stanley and Planetary Magnetic Fields . .78 7. Surface Appearance and Conditions on Neptune . .81 8. Neptune’s Rings and Moons . .85 Rings . .85 Moons . .88 Fossa,Sulci,and Other Terms for Planetary Landforms . .96 PART TWO: PLUTO AND THE KUIPER BELT 9. The Discovery of Pluto and the Kuiper Belt . .101 10. Pluto: Fast Facts about a Dwarf Planet in Orbit . .109 Fundamental Information about Pluto . .110 11. What Little Is Known about Pluto’s Interior and Surface . .113 12. Charon: Pluto’s Moon, or Its Companion Dwarf Planet? . .121 13. The Rest of the Kuiper Belt Population . .125 Numbering and Naming Small Bodies . .128 PART THREE: BEYOND THE KUIPER BELT 14. The Oort Cloud . .145 15. Conclusions: The Known and the Unknown . .151 Appendix 1: Units and Measurements . .159 Fundamental Units . .159 Comparisons among Kelvin, Celsius, and Fahrenheit . .161 Useful Measures of Distance . .163 Definitions for Electricity and Magnetism . .167 Prefixes . .170 Appendix 2: Light,Wavelength, and Radiation . .171 Appendix 3: A List of All Known Moons . .180 Glossary . .182 Bibliography and Further Reading . .190 Internet Resources . .191 Organizations of Interest . .193 Index . .195 mPreface he planets Mercury,Venus,Mars, Jupiter, and Saturn—all visible Tto the naked eye—were known to ancient peoples. In fact, the Romans gave these planets their names as they are known today. Mercury was named after their god Mercury, the fleet-footed messen- ger of the gods, because the planet seems especially fast moving when viewed from Earth.Venus was named for the beautiful goddess Venus, brighter than anything in the sky except the Sun and Moon.The planet Mars appears red even from Earth and so was named after Mars, the god of war. Jupiter was named for the king of the gods, the biggest and most powerful of all, and Saturn was named for Jupiter’s father. The ancient Chinese and the ancient Jews recognized the planets as well, and the Maya (250–900 C.E., Mexico and environs) and Aztec (ca. 1100–1700 C.E., Mexico and environs) called the planet Venus “Quetzalcoatl,” after their god of good and light. These planets, small and sometimes faint in the night sky, com- manded such importance that days were named after them. The seven-day week originated in Mesopotamia, which was perhaps the world’s first organized civilization (beginning around 3500 B.C.E.in modern-day Iraq). The Romans adopted the seven-day week almost 4,000 years later, around 321 C.E., and the concept spread through- out western Europe. Though there are centuries of translations between their original names and current names, Sunday is still named for the Sun, Monday for the Moon, Tuesday for Mars, Wednesday for Mercury,Thursday for Jupiter, Friday for Venus, and Saturday for Saturn. The Germanic peoples substituted Germanic equivalents for the names of four of the Roman gods: For Tuesday, Tiw, the god of war, replaced Mars; for Wednesday,Woden, the god of wisdom, replaced Mercury; for Thursday,Thor, the god of thun- der, replaced Jupiter; and for Friday, Frigg, the goddess of love, replaced Venus. ix x B Uranus, Neptune, Pluto, and the Outer Solar System More planets, of course, have been discovered by modern man, thanks to advances in technology.Science is often driven forward by the development of new technology, allowing researchers to make meas- urements that were previously impossible.The dawn of the new age in astronomy, the study of the solar system, occurred in 1608, when Hans Lippershey, a Dutch eyeglass-maker, attached a lens to each end of a hollow tube, creating the first telescope. Galileo Galilei, born in Pisa, Italy, in 1564, made his first telescope in 1609 from Lippershey’s model. Galileo soon had noticed that Venus has phases like the Moon and that Saturn appeared to have “handles.”These of course were the edges of Saturn’s rings, though the telescope was not strong enough to resolve the rings correctly. In 1610, Galileo discovered four of Jupiter’s moons, which are still called the Galilean satellites.These four moons were proof that not every heavenly body orbited the Earth, as Ptolemy, a Greek philosopher, had asserted around 140 C.E. Galileo’s discovery was the beginning of the end of the strongly held belief that the Earth is the center of the solar system, as well as a beautiful example of a case where improved technology drove science forward. Most of the science presented in this set comes from the startling- ly rapid developments of the last hundred years, brought about by technological development.The concept of the Earth-centered solar system is long gone, as is the notion that the “heavenly spheres” are unchanging and perfect. Looking down on the solar system from above the Sun’s North Pole, the planets orbiting the Sun can be seen to be orbiting counterclockwise, in the manner of the original proto- planetary disk of material from which they formed. (This is called pro- grade rotation.) This simple statement, though, is almost the end of generalities about the solar system.The notion of planets spinning on their axes and orbiting around the Sun in an orderly way is incorrect: Some planets spin backward compared to the Earth, others planets are tipped over, and others orbit outside the ecliptic plane (the imagi- nary plane that contains the Earth’s orbit) by substantial angles, the dwarf planet Pluto in particular (see the accompanying figure on obliquity and orbital inclination). Some planets and moons are hot enough to be volcanic, and some produce silicate lava (for example, Jupiter’s moon Io), while others have exotic lavas made of molten ices (for example, Neptune’s moon Triton). Some planets and even moons have atmospheres, with magnetic fields to protect them from the solar wind (for example,Venus, Earth, Mars, Io,Triton, and Saturn’s Preface y xi moon Titan), while other planets have lost both their magnetic fields and their atmospheres and orbit the Sun fully exposed to its radiation and supersonic particles (for example, Mercury). Size can be unexpected in the solar system: Saturn’s moon Titan is larger than the planet Mercury, and Charon, Pluto’s moon, is almost as big as Pluto itself. The figure on page xii shows the number of moons each planet has; large planets have far more than small planets, and every year scientists discover new celestial bodies orbiting the gas giant planets. Many large bodies orbit in the asteroid belt, or the Kuiper belt, and many sizable asteroids cross the orbits of planets as they make their way around the Sun. Some planets’ moons are unsta- ble and will make new ring systems as they crash into their hosts. Many moons, like Neptune’s giant Triton, orbit their planets back- ward (clockwise when viewed from the North Pole, the opposite way Obliquity, orbital inclination, that the planets orbit the Sun).Triton also has the coldest surface tem- and rotation direction are perature of any moon or planet, including Pluto, which is much far- three physical measurements ther from the Sun.The solar system is made of bodies in a continuum used to describe a rotating, of sizes and ages, and every rule has an exception.
Recommended publications
  • 7 Planetary Rings Matthew S
    7 Planetary Rings Matthew S. Tiscareno Center for Radiophysics and Space Research, Cornell University, Ithaca, NY, USA 1Introduction..................................................... 311 1.1 Orbital Elements ..................................................... 312 1.2 Roche Limits, Roche Lobes, and Roche Critical Densities .................... 313 1.3 Optical Depth ....................................................... 316 2 Rings by Planetary System .......................................... 317 2.1 The Rings of Jupiter ................................................... 317 2.2 The Rings of Saturn ................................................... 319 2.3 The Rings of Uranus .................................................. 320 2.4 The Rings of Neptune ................................................. 323 2.5 Unconfirmed Ring Systems ............................................. 324 2.5.1 Mars ............................................................... 324 2.5.2 Pluto ............................................................... 325 2.5.3 Rhea and Other Moons ................................................ 325 2.5.4 Exoplanets ........................................................... 327 3RingsbyType.................................................... 328 3.1 Dense Broad Disks ................................................... 328 3.1.1 Spiral Waves ......................................................... 329 3.1.2 Gap Edges and Moonlet Wakes .......................................... 333 3.1.3 Radial Structure .....................................................
    [Show full text]
  • Planetary Ring Systems Edited by Matthew S
    Cambridge University Press 978-1-107-11382-4 — Planetary Ring Systems Edited by Matthew S. Tiscareno , Carl D. Murray Frontmatter More Information Planetary Ring Systems Properties, Structure, and Evolution Planetary rings are among the most intriguing structures of our solar system and have fas- cinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring-particle orbits is followed by a review of the known planetary ring sys- tems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties, their origins, and investigations using com- puter simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field’s future. Researchers of all levels benefit from this thorough and engaging presentation. MATTHEW S. TISCARENO is a Senior Research Scientist at the SETI Institute, California. He is a Participating Scientist and an Imaging Team Associate with the Cassini- Huygens mission. His research output includes solar system dynamics and space-based observations of the outer solar system. CARL D. MURRAYis Professor of Mathematics and Astronomy at Queen Mary Univer- sity of London. He has contributed to numerous ring and moon discoveries as an original member of the Imaging Team with the Cassini-Huygens mission and he is co-author of the textbook Solar System Dynamics (1999).
    [Show full text]
  • The L3 Exhibitions Catalogue 2010-2014
    The L3 Exhibitions Catalogue 2010-2014 Leonardo da Vinci overview Leonardo da Vinci is a universal genius. He What the public knows about Leonardo is bare- was, of course, an Italian, but he belongs to a ly the tip of the iceberg. His manuscripts con- past that is part of the cultural heritage of every tinue to hide secrets and are worthy of inquiry person and every nation. He is a singular exam- and presentation in new, innovative ways. L3 ple throughout history of a man who possessed explores, discovers and reveals the “unknown an enormous talent and excelled not only as a Leonardo” in order to spark the hidden genius scientist, but also as an artist. Most of the inven- that lies within us all. tions and machines that he designed can in fact be considered works of art. On the same note, Leonardo3 (L3) is the world leader in exclu- his artistic works are both the creations of a sive exhibitions and publications on da Vinci’s master artist and the products of a formidable genius. Each of our exhibitions is the result of scientific brain. work carried out by our own team of researchers who investigate and develop never-seen-before Just as his paintings deserve the kind of investi- machines for each event. gation to which only today’s technology can do justice, so the full extent of his scientific work Our exhibitions are “dynamic” rather than “stat- has yet to be revealed to the public. ic”. We make extensive use of 3D animations, physical models and interactive software to of- fer the public a unique level of interaction and a hands-on “edu-tainment” experience.
    [Show full text]
  • Weighing Uranus' Moon Cressida with the Η Ring
    The Astronomical Journal, 154:153 (8pp), 2017 October https://doi.org/10.3847/1538-3881/aa880e © 2017. The American Astronomical Society. All rights reserved. Weighing Uranus’ Moon Cressida with the η Ring Robert O. Chancia1 , Matthew M. Hedman1 , and Richard G. French2 1 Department of Physics, University of Idaho, Moscow, ID 83844-0903, USA; [email protected] 2 Astronomy Department, Wellesley College, Wellesley, MA 02481, USA Received 2017 June 19; revised 2017 August 9; accepted 2017 August 21; published 2017 September 20 Abstract The η ring is one of the narrow rings of Uranus, consisting of a dense core that is 1–2 km wide and a diffuse outer sheet spanning about 40 km. Its dense core lies just exterior to the 3:2 Inner Lindblad Resonance of the small moon Cressida. We fit the η ring radius residuals and longitudes from a complete set of both ground-based and Voyager stellar and radio occultations of the Uranian rings spanning 1977–2002. We find variations in the radial position of the η ring that are likely generated by this resonance, and take the form of a 3-lobed structure rotating at an angular rate equal to the mean motion of the moon Cressida. The amplitude of these radial oscillations is 0.667±0.113 km, which is consistent with the expected shape due to the perturbations from Cressida. The magnitude of these variations provides the first measurement of the mass and density of the moon Cressida (m =´()2.5 0.4 1017 kg and r =0.86 0.16 gcm−3) or, indeed, any of Uranus’ small inner moons.
    [Show full text]
  • Arxiv:1509.00872V1 [Astro-Ph.EP] 2 Sep 2015 H Bevblt Fipcso in Xpaes H Oe Matc Impact Comet the Exoplanets
    Detectability of Planetesimal Impacts on Giant Exoplanets Laura Flagga,b,∗, Alycia J. Weinbergerb, Keith Matthewsc aDepartment of Physics and Astronomy, Northern Arizona University, Flagstaff, AZ 86011-6010, USA bDepartment of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015, USA cCaltech Optical Observatories, California Institute of Technology, MC 301-17, Pasadena, CA 91125, USA Abstract The detectability of planetesimal impacts on imaged exoplanets can be measured using Jupiter during the 1994 comet Shoemaker-Levy 9 events as a proxy. By integrating the whole planet flux with and without impact spots, the effect of the impacts at wavelengths from 2 - 4 µm is revealed. Jupiter’s reflected light spectrum in the near-infrared is dominated by its methane opacity including a deep band at 2.3 µm. After the impact, sunlight that would have normally been absorbed by the large amount of methane in Jupiter’s atmosphere was instead reflected by the cometary material from the impacts. As a result, at 2.3 µm, where the planet would normally have low reflectivity, it brightened substantially and stayed brighter for at least a month. Keywords: comets, debris disks, extra-solar planets, Jupiter 1. Introduction The frequencies with which giant planets and cold circumstellar debris disks encircle old (i.e. >1 Gyr) Sun-like stars are both ∼20% (Eiroa et al. 2013; Marshall et al. 2014). The debris disks are generated in the collisions and evaporation of planetesimals, analogous to the comets and asteroids of today’s Solar System. That most debris disks contain cold, ∼50 K, dust indicates that the reservoirs of parent bodies are at ∼100 AU from the parent stars, in a region analogous to our Edgeworth-Kuiper Belt.
    [Show full text]
  • Aqueous Alteration on Main Belt Primitive Asteroids: Results from Visible Spectroscopy1
    Aqueous alteration on main belt primitive asteroids: results from visible spectroscopy1 S. Fornasier1,2, C. Lantz1,2, M.A. Barucci1, M. Lazzarin3 1 LESIA, Observatoire de Paris, CNRS, UPMC Univ Paris 06, Univ. Paris Diderot, 5 Place J. Janssen, 92195 Meudon Pricipal Cedex, France 2 Univ. Paris Diderot, Sorbonne Paris Cit´e, 4 rue Elsa Morante, 75205 Paris Cedex 13 3 Department of Physics and Astronomy of the University of Padova, Via Marzolo 8 35131 Padova, Italy Submitted to Icarus: November 2013, accepted on 28 January 2014 e-mail: [email protected]; fax: +33145077144; phone: +33145077746 Manuscript pages: 38; Figures: 13 ; Tables: 5 Running head: Aqueous alteration on primitive asteroids Send correspondence to: Sonia Fornasier LESIA-Observatoire de Paris arXiv:1402.0175v1 [astro-ph.EP] 2 Feb 2014 Batiment 17 5, Place Jules Janssen 92195 Meudon Cedex France e-mail: [email protected] 1Based on observations carried out at the European Southern Observatory (ESO), La Silla, Chile, ESO proposals 062.S-0173 and 064.S-0205 (PI M. Lazzarin) Preprint submitted to Elsevier September 27, 2018 fax: +33145077144 phone: +33145077746 2 Aqueous alteration on main belt primitive asteroids: results from visible spectroscopy1 S. Fornasier1,2, C. Lantz1,2, M.A. Barucci1, M. Lazzarin3 Abstract This work focuses on the study of the aqueous alteration process which acted in the main belt and produced hydrated minerals on the altered asteroids. Hydrated minerals have been found mainly on Mars surface, on main belt primitive asteroids and possibly also on few TNOs. These materials have been produced by hydration of pristine anhydrous silicates during the aqueous alteration process, that, to be active, needed the presence of liquid water under low temperature conditions (below 320 K) to chemically alter the minerals.
    [Show full text]
  • Exploring the Origins and Evolution of Ice Giant Planets
    Exp Astron DOI 10.1007/s10686-011-9251-4 ORIGINAL ARTICLE Uranus Pathfinder: exploring the origins and evolution of Ice Giant planets Christopher S. Arridge Craig B. Agnor Nicolas André Kevin H. Baines · · · · Leigh N. Fletcher Daniel Gautier Mark D. Hofstadter Geraint H. Jones · · · · Laurent Lamy Yves Langevin Olivier Mousis Nadine Nettelmann · · · · Christopher T. Russell Tom Stallard Matthew S. Tiscareno · · · Gabriel Tobie Andrew Bacon Chris Chaloner Michael Guest · · · · Steve Kemble Lisa Peacocke Nicholas Achilleos Thomas P. Andert · · · · Don Banfield Stas Barabash Mathieu Barthelemy Cesar Bertucci · · · · Pontus Brandt Baptiste Cecconi Supriya Chakrabarti Andy F. Cheng · · · · Ulrich Christensen Apostolos Christou Andrew J. Coates · · · Glyn Collinson John F. Cooper Regis Courtin Michele K. Dougherty · · · · Robert W. Ebert Marta Entradas Andrew N. Fazakerley · · · Jonathan J. Fortney Marina Galand Jaques Gustin Matthew Hedman · · · · Ravit Helled Pierre Henri Sebastien Hess Richard Holme · · · · Özgur Karatekin Norbert Krupp Jared Leisner Javier Martin-Torres · · · · Adam Masters Henrik Melin Steve Miller Ingo Müller-Wodarg · · · · Benoît Noyelles Chris Paranicas Imke de Pater Martin Pätzold · · · · Renée Prangé Eric Quémerais Elias Roussos Abigail M. Rymer · · · · Agustin Sánchez-Lavega Joachim Saur Kunio M. Sayanagi Paul Schenk · · · · Gerald Schubert Nick Sergis Frank Sohl Edward C. Sittler Jr. · · · · Nick A. Teanby Silvia Tellmann Elizabeth P. Turtle Sandrine Vinatier · · · · Jan-Erik Wahlund Philippe Zarka · Received: 26 November 2010 / Accepted: 21 July 2011 ©SpringerScience+BusinessMediaB.V.2011 N. Achilleos Department of Physics and Astronomy, University College London, London, UK C. B. Agnor School of Physics and Astronomy, Queen Mary University of London, London, UK T. P. Andert Universität der Bundeswehr, Munich, Germany N. André Centre d’Etude Spatiale des Rayonnements / CNRS, Toulouse, France C.
    [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]
  • Introductory Astronomy Course at UMD With
    Introductory Course at UMD with Remote Observing - “Astronomy in Practice” Dr. Melissa N. Hayes-Gehrke Astronomy Dept., UMD 1 2016 GROWTH Education Workshop Overarching Goal Involve non-astronomy students in real astronomical research so that they develop a better understanding of how astronomy, and thus science overall, really works. 2 Talk Outline ● Course Opportunity and Target Student Population ● Educational Goals ● Course Organization and Structure ● Project Execution ● Results: Projects and Course Success 3 Course Opportunity and Target Student Population ● New “Scholarship in Practice” courses at UMD provided the opportunity to develop this course – our department wanted one because all students are required to take two. ● Asteroids are perfect target objects for student research since the required observations and analysis are straightforward, yet new results are possible because of >100,000 unstudied asteroids. 4 Course Opportunity and Target Student Population Target student population: ● Non-astronomy major, may not be science major ● May have only algebra-level math ● May not have any astronomy background 5 Course Opportunity and Target Student Population Example population from most recent course offering (46 students): ● Mostly sophomore/junior ● 33% URMs (including women) ● 25% female ● average GPA of class: 2.9 ● 43% computer science, 13% undecided, 9% biology, 7% engineering ● Many are (or became) astronomy minors 6 Educational Goals The course satisfies learning goals at multiple levels: ● Instructor's astronomical knowledge goals ● University's goals for Scholarship in Practice courses 7 Educational Goals: Instructor's Goals Students will have: ● An understanding of our place in the solar system and how asteroids fit into the solar system. ● An understanding of how astronomers study asteroids.
    [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]
  • Jupiter's Ring-Moon System
    11 Jupiter’s Ring-Moon System Joseph A. Burns Cornell University Damon P. Simonelli Jet Propulsion Laboratory Mark R. Showalter Stanford University Douglas P. Hamilton University of Maryland Carolyn C. Porco Southwest Research Institute Larry W. Esposito University of Colorado Henry Throop Southwest Research Institute 11.1 INTRODUCTION skirts within the outer stretches of the main ring, while Metis is located 1000 km closer to Jupiter in a region where the ∼ Ever since Saturn’s rings were sighted in Galileo Galilei’s ring is depleted. Each of the vertically thick gossamer rings early sky searches, they have been emblematic of the ex- is associated with a moon having a somewhat inclined orbit; otic worlds beyond Earth. Now, following discoveries made the innermost gossamer ring extends towards Jupiter from during a seven-year span a quarter-century ago (Elliot and Amalthea, and exterior gossamer ring is connected similarly Kerr 1985), the other giant planets are also recognized to be with Thebe. circumscribed by rings. Small moons are always found in the vicinity of plane- Jupiter’s diaphanous ring system was unequivocally de- tary rings. Cuzzi et al. 1984 refer to them as “ring-moons,” tected in long-exposure images obtained by Voyager 1 (Owen while Burns 1986 calls them “collisional shards.” They may et al. 1979) after charged-particle absorptions measured by act as both sources and sinks for small ring particles (Burns Pioneer 11 five years earlier (Fillius et al. 1975, Acu˜na and et al. 1984, Burns et al. 2001). Ness 1976) had hinted at its presence. The Voyager flybys also discovered three small, irregularly shaped satellites— By definition, tenuous rings are very faint, implying Metis, Adrastea and Thebe in increasing distance from that particles are so widely separated that mutual collisions Jupiter—in the same region; they joined the similar, but play little role in the evolution of such systems.
    [Show full text]
  • Giant Planets
    Giant Planets Mark Marley (NASA Ames) for the Planetary Decadal Survey Giant Planets Subpanel Tuesday, December 22, 2009 1 GPP Membership Reta Beebe Brigette Hesman Wayne Richie NMSU NRAO NASA Langley atmos. dynamics atm chemistry engineer John Casani William Hubbard Kunio Sayanagi JPL University of Arizona CalTech engineer, NAE interiors dynamics, theory John Clarke Mark Marley Amy Simon-Miller Boston University NASA Ames NASA Goddard aurorae, magnetos. exoplanets panel vice-chair Heidi Hammel Phil Nicholson Space Science Cornell University Institute rings panel chair Tuesday, December 22, 2009 2 Today • Some highlights of giant planet science in the past decade that impact future exploration goals (personal perspective, neglecting Cassini) • Stressing: Connection to brown dwarfs & 400+ exoplanets • Decadal process • whitepapers • mission studies • key technologies • community input Tuesday, December 22, 2009 3 Solar System Jovian Planets Serve as Waypoints in a Continuum of Objects Tuesday, December 22, 2009 4 TiO FeH K H2O H2O 6 H2O M6.5 V 10 L5 H O T.5 CO 2 Jupiter K M6 4 CIA H2 10 CH4 CH4 CH4 CH4 CH4 L5 CH4 NH3 2 10 T5 CH4 (1.30µm) x Constant ! f NH ! 3 / ! f ! 100 Jupiter CH4 1 2 3 4 5 6 7 8 9 10 Wavelength (µm) Marley & Leggett (2009) Tuesday, December 22, 2009 5 oklo.org Tuesday, December 22, 2009 6 15 ) • Transiting planets 10Earth reveal a continuum of M, R • Microlensing suggests Radius (R Neptunes are 5 common 0.1 1000 Charbonneau et al. (2009) Charbonneau et al. Mass (MEarth) Tuesday, December 22, 2009 7 Some Highlights and Questions Tuesday, December 22, 2009 8 signature of planethood? vary with mass? Owen et al.
    [Show full text]