DOCSLIB.ORG

The Planetary Report

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

The Volume XVII 01) the Cover: "Fantastically weird" slipped out as geologist Jim Head Table of Number 2 described the latest Galileo images of Euro~a. Thi ~ is one March/April1997 of the most enigmatic worlds yet seen by spacecraft, and Contents the closer we look, the stranger it gets. It may possess an ocean beneath a water-ice crust, perhaps hiding a potential habitat for life. Here we show the moon as it appeared from 677,000 ki lometers (420,000 miles) away last September during Galileo's flyby of Gany mede. At left is a false-color Features image, with contrasts enhanced to bring out compositional Waltzing by Mathilde: differences in the primarily ice crust. At right is a natural­ 4 NEAR's First Asteroid Encounter color image, showing Europa as it might appear to an Asteroids aren't the most glamorous objects in the solar system, but they contain crucial observer riding the spacecraft. Images: JPUNASA clues to the origin and evolution of our planetary family. Plus, those that pass through Earth 's neighborhood pose a distinct threat to the future evolution of some life-forms on this planet. On its way to explore the tiny world Eros, the Near-Earth Asteroid Rendezvous spacecraft is preparing to encounter another small object with great potential, Mathilde. Froln 9 Farevvell, Pioneer The The Voyagers' flights through the outer solar system may have been more thrilling, and the CaWeo mission to the Jupiter system will produce more data, but both these missions Editor depended for their success on the first spacecraft to blaze a trail to the outer solar system: Pioneer 10. That hardy little craft, still operating after 25 years, will soon fall silent­ a victim of budget cuts, not the rigors of space. he theme has pervaded the space Tprogram since its birth, some­ 10 Weird and Wonderful: times playing softly in the background, Europa Keeps Her Secrets other times forcefully dominating So far we have conclusive evidence of a global ocean on only one world-Earth. But missions and programs. That theme is, Jupiter's moon Europa has tantalized scientists with hints that it, too, may possess large of course, life in the universe. With bodies of liquid water, even if they are hidden beneath an icy shroud. Calileo has sent us CaWeo circling closer and closer to the best images yet of this weird little world, but as yet there is no way to know for certain Europa, spll,cecraft flying to Mars, and if there is a Europan ocean. powerful telescopes finding more and Sagan's Fire: more planets around other stars, the 14 A Nevv Challenge theme is once again g~ining power. The Planetary Society faces a future filled with challenge and opportunity. Bruce Murray, NASA has committed to extending Acting President, and Louis D. Friedman, Executive Director, ask your help in guiding the CaWeo's funding to cover the Europa Society to the best of all possible futures. Extended Mission, in the hopes of determining if an ocean lies beneath its icy surface. Both NASA and the Departlnents National Science Foundation are encouraging research to determine if 3 Men1lbers' Dialogue the meteorite ALH84001 does hold traces of ancient Martian life. Returning 15 World Watch a sample of Mars to Earth has gained priority in NASA's plans for the next 16 Basics of Spaceflight century. And questions concerning 18 Nevvs and Revievvs extrasolar planets have shifted from "Do they exist?" to "Which ones 1 9 Society Nevvs might support life?" This is a time of fantastic opportu­ 20 Questions and Ansvvers nity for the Planetary Society to reach an increasingly receptive audience with our message. The only way to find life on other worlds is to explore Contact Us them. It's our job to make that happen. --Charlene M. Anderson Mailing Addres s: The Plan etary SOC iety, 65 North Catalina Aven ue, Pasadena, CA 91106-2301 General Calls: 818-793-5100 Sales Calls Only: 818-793-1675 E-mail: tps @mars .planetary.org World Wide Web Home Page : http ://p lanetary.org /tps/ The Planetary Report (ISSN 0736-3680) is published bimonthly al the editorial oHices of the Planetary Society, 65 North Catalina Avenue, Pasadena, CA 91106-2301,818-793-5100. II is available to members of the Planetary Society. Annual dues in the US are $25 (US dollars); in Canada, $35 (Canadian dollars). Dues in other countries are $45 (US dollars). Printed in USA. Third-class postage at Pasadena, California, and at an additional mailing office. Canada Post Agreement Number 87424 A ..... ... '" , Editor, CHARLENE M. ANDERSON Technical Editor, JAMES D. BURKE ~ Assistant Editor, DONNA ESCANDON STEVENS Copy Editor, KARL STULL THE-PL.A~TfRV SOCIETY Production Editor, WILLIAM MCGOVERN Art Director, BARBARA S. SMITH Editorial Assistant, JENNIFER VAUGHN o .~ -e- ¢ -e- 0 ViewPoints expre ssed in columns or editorials are those of the authors and do not necessarily represent pOSitions of the Planetary Society, • its officers, or advisors. © 1997 by the Planetary Society. o .---------------------------IF-===========~~~--~~~---=========······==~----·------·---- Co-f'ounder CARL SAGAN Members' 1934· 1996 Board of Directors BRUCE MURRAY Dialogue Vice Presi dent Professor of Planetary Science, california Institute of Technology LOUIS D. FRIEOMAN Executive Director NORMAN R. AUGUSTI NE PreSident, Lockheed Martin Corporation JOSEPH RYAN Executive Vice President and General Counsel, Marriott International STEVEN SPIELBERG director and producer LAUREL L WILKENING Chancelfor, University of California, Irvine Another option? a desire to be rid of the endless tion award to Project BETA (see Board of Advisors Soon after hearing about the government bureaucracies the November/December 1996 DIANE ACKERMAN demise ofthe Mars '96 mission involved in space exploration. Members' Dialogue) is a remind­ poet and author BUZZ AL DR IN I realized that the microdot But I believe that privatization er to us all of the best humanity Apu lia 11 astronaut RICHARD BERENOZEN with Planetary Society members' will replace the endless govern­ has to offer and why, eventually, educator and astrophysicist names was lost too, and I was ment problems with endless we may be worthy representatives JACQUES BLAMONT Chief Scientist, Centre National saddened even further. I urge business problems. of our planet in whatever commu­ d'Etudes Spatia/es, France the Society to approach NASA I think government involve­ nity the universe has to offer. RAY BRADBURY poet and author with a proposal to refly the lost ment at this time is good. This --EVAN MALONE, ARTH UR C. CLARKE microdot and the Visions of allows the motives to be set Philadelphia, Pennsylvania author CORNELIS DE JAGER Mars CD-ROM on the 1998 more by people than by profit. Professor of Space Research, The Aslronomicallnstitute at Utrecht, Mars Surveyor lander mission. A private company is under no Praise the Netherlands The opportunity to have one's obligation to listen to voters. It Thank you for existing-for FRANK DRAKE Professor of Astronomy and Astrophysics, name fly to the Red Planet on a would pay more heed to markets remaining a strong voice, always University of California, Santa Cruz JOHN GARDNER robotic explorer is a very roman­ and backers. A government-sup­ informing and enlightening the founder, Common Cause tic notion indeed. I hope that you ported J1rivate company could public about the many wonders MARC GARN EAU will soon be approaching NASA turn its attention from survival of our solar system and beyond. Canadian astronaut GEORG IY GDLlTSYN to suggest the inclusion of these and business to what people in I appreciate the fact that the Institute of Atmospheric Physics, Russian Academy of Sciences important "payloads." general are interested in doing. Society has spoken to those in THEODORE M, HESBURGH President Emeritus, --JOEL W POWELL, But such a company is no longer our government to ensure that University of Notre Dame Calgary, Alberta, Canada free from government or private they are made aware of the great SHIRLEY M. HUFSTEDLER bureaucracies. importance of such experiments educator and jurist GARRY E. HUNT It is too late and probably tech­ Things should stay as they as the Mars Balloon. I thank your space SCientist, United Kingdom nically impossible to put Visions are until it's more reasonable for organization, Louis Friedman, SERG EI KAPITSA fnstitute for Physical Problems, of Mars on the 1998 Mars private citizens to undertake and Carl Sagan for your contin­ Russian Academy of Sciences GEN. DONALD J. KUTYN A (RET.) Surveyor lander. That mission businesses involved with being ued hard work and for sharing it former Commander, US Space Command has very tight weight and volume m space. with those who are interested. JOHN M, LOGSDON Director, Space Policy Institute, constraints. The CD also con­ -PAUL RICHMAN, - SHAWNA MERLIN George Washington University tains material particular to Mars Vancouver, British Columbia, BURCH, Boise, Idaho HANS MARK The University of Texas at Austin '96 and should be changed to fly Canada JAMES MICHENER on another mission. The small NASA's Budget author MARVIN MI NSKY stations, on which were mounted Inspiration Regarding the issue of spending Toshiba Professor of Media Ans and SCiences, the CD and the special Society Although I am frequently struck NASA's money on social pro­ Massachusetts Institute of Technology label with the radiation recorder with awe by the photographs jects rather than on space explo­ PHILIP MORRISON Institute Professor, and our members' names, is being presented in your magazine and ration, consider this: if Queen Massachusetts Insti(ute of Technology PAUL NEWMAN considered for flight in 2001 as often moved by the wonderful Isabella had taken the money actor part of "Mars Together." We will example of cooperative effort she gave Christopher Columbus JUN NISHI MURA former Director General, certainly discuss this with NASA between the public and profes­ and invested it in social projects Institute of Space and Astronautical SCience, Japan sionals (and even policy-makers) and the Russian Space Agency instead, just imagine the utopia SALLY RIOE Professor of Physics, as an idea for Mars landers in that the Planetary Society repre­ Spain would be today.
Recommended publications
  • Planetary Report Report

    Planetary Report Report

    The PLANETARYPLANETARY REPORT REPORT Volume XXV Number 5 September/October 2005 ATACAMA DESERT MarsMars AnalogsAnalogs VALLES MARINERIS Volume XXV Table of Number 5 Contents September/October 2005 A PUBLICATION OF Features From The Dry Earth, Wet Mars 6 Sometimes the best place to learn about Mars exploration is right here on Editor Earth. In Chile’s Atacama Desert, scientists have discovered an area so dry that organic material, and therefore evidence of life, is virtually undetectable. Study of he damage that Earth inflicts on her this parched Mars-like region on Earth may lead us to a better understanding of Tinhabitants—horribly demonstrated how to search for water and the elements of life in Martian soil. This year, The by Hurricane Katrina and the December Planetary Society cosponsored a field expedition to the Atacama Desert, sending tsunami—reminds us what fragile creatures graduate student Troy Hudson on a 1-week adventure with a team of scientists led we are, lucky to survive at all on this dynamic, by Society Board member Chris McKay. Here, Troy describes his experience. dispassionate ball of rock hurtling through space. 12 The Pioneer Anomaly: A Deep Space Mystery Our exploration of other worlds has As Pioneer 10 and 11 head toward the farthest reaches of our solar system, taught us that the potential for planetary something strange is happening—they are mysteriously slowing down. Scientists catastrophe is always with us. On Mars, do not yet know why the spacecraft aren’t acting as expected; however, The we’ve seen planet-rending gouges cut by Planetary Society has stepped in to help fund the effort to analyze roughly 25 years catastrophic floods.
  • The Minor Planet Bulletin

    The Minor Planet Bulletin

    THE MINOR PLANET BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS VOLUME 36, NUMBER 3, A.D. 2009 JULY-SEPTEMBER 77. PHOTOMETRIC MEASUREMENTS OF 343 OSTARA Our data can be obtained from http://www.uwec.edu/physics/ AND OTHER ASTEROIDS AT HOBBS OBSERVATORY asteroid/. Lyle Ford, George Stecher, Kayla Lorenzen, and Cole Cook Acknowledgements Department of Physics and Astronomy University of Wisconsin-Eau Claire We thank the Theodore Dunham Fund for Astrophysics, the Eau Claire, WI 54702-4004 National Science Foundation (award number 0519006), the [email protected] University of Wisconsin-Eau Claire Office of Research and Sponsored Programs, and the University of Wisconsin-Eau Claire (Received: 2009 Feb 11) Blugold Fellow and McNair programs for financial support. References We observed 343 Ostara on 2008 October 4 and obtained R and V standard magnitudes. The period was Binzel, R.P. (1987). “A Photoelectric Survey of 130 Asteroids”, found to be significantly greater than the previously Icarus 72, 135-208. reported value of 6.42 hours. Measurements of 2660 Wasserman and (17010) 1999 CQ72 made on 2008 Stecher, G.J., Ford, L.A., and Elbert, J.D. (1999). “Equipping a March 25 are also reported. 0.6 Meter Alt-Azimuth Telescope for Photometry”, IAPPP Comm, 76, 68-74. We made R band and V band photometric measurements of 343 Warner, B.D. (2006). A Practical Guide to Lightcurve Photometry Ostara on 2008 October 4 using the 0.6 m “Air Force” Telescope and Analysis. Springer, New York, NY. located at Hobbs Observatory (MPC code 750) near Fall Creek, Wisconsin.
  • Observations from Orbiting Platforms 219

    Observations from Orbiting Platforms 219

    Dotto et al.: Observations from Orbiting Platforms 219 Observations from Orbiting Platforms E. Dotto Istituto Nazionale di Astrofisica Osservatorio Astronomico di Torino M. A. Barucci Observatoire de Paris T. G. Müller Max-Planck-Institut für Extraterrestrische Physik and ISO Data Centre A. D. Storrs Towson University P. Tanga Istituto Nazionale di Astrofisica Osservatorio Astronomico di Torino and Observatoire de Nice Orbiting platforms provide the opportunity to observe asteroids without limitation by Earth’s atmosphere. Several Earth-orbiting observatories have been successfully operated in the last decade, obtaining unique results on asteroid physical properties. These include the high-resolu- tion mapping of the surface of 4 Vesta and the first spectra of asteroids in the far-infrared wave- length range. In the near future other space platforms and orbiting observatories are planned. Some of them are particularly promising for asteroid science and should considerably improve our knowledge of the dynamical and physical properties of asteroids. 1. INTRODUCTION 1800 asteroids. The results have been widely presented and discussed in the IRAS Minor Planet Survey (Tedesco et al., In the last few decades the use of space platforms has 1992) and the Supplemental IRAS Minor Planet Survey opened up new frontiers in the study of physical properties (Tedesco et al., 2002). This survey has been very important of asteroids by overcoming the limits imposed by Earth’s in the new assessment of the asteroid population: The aster- atmosphere and taking advantage of the use of new tech- oid taxonomy by Barucci et al. (1987), its recent extension nologies. (Fulchignoni et al., 2000), and an extended study of the size Earth-orbiting satellites have the advantage of observing distribution of main-belt asteroids (Cellino et al., 1991) are out of the terrestrial atmosphere; this allows them to be in just a few examples of the impact factor of this survey.
  • CURRICULUM VITAE, ALAN W. HARRIS Personal: Born

    CURRICULUM VITAE, ALAN W. HARRIS Personal: Born

    CURRICULUM VITAE, ALAN W. HARRIS Personal: Born: August 3, 1944, Portland, OR Married: August 22, 1970, Rose Marie Children: W. Donald (b. 1974), David (b. 1976), Catherine (b 1981) Education: B.S. (1966) Caltech, Geophysics M.S. (1967) UCLA, Earth and Space Science PhD. (1975) UCLA, Earth and Space Science Dissertation: Dynamical Studies of Satellite Origin. Advisor: W.M. Kaula Employment: 1966-1967 Graduate Research Assistant, UCLA 1968-1970 Member of Tech. Staff, Space Division Rockwell International 1970-1971 Physics instructor, Santa Monica College 1970-1973 Physics Teacher, Immaculate Heart High School, Hollywood, CA 1973-1975 Graduate Research Assistant, UCLA 1974-1991 Member of Technical Staff, Jet Propulsion Laboratory 1991-1998 Senior Member of Technical Staff, Jet Propulsion Laboratory 1998-2002 Senior Research Scientist, Jet Propulsion Laboratory 2002-present Senior Research Scientist, Space Science Institute Appointments: 1976 Member of Faculty of NATO Advanced Study Institute on Origin of the Solar System, Newcastle upon Tyne 1977-1978 Guest Investigator, Hale Observatories 1978 Visiting Assoc. Prof. of Physics, University of Calif. at Santa Barbara 1978-1980 Executive Committee, Division on Dynamical Astronomy of AAS 1979 Visiting Assoc. Prof. of Earth and Space Science, UCLA 1980 Guest Investigator, Hale Observatories 1983-1984 Guest Investigator, Lowell Observatory 1983-1985 Lunar and Planetary Review Panel (NASA) 1983-1992 Supervisor, Earth and Planetary Physics Group, JPL 1984 Science W.G. for Voyager II Uranus/Neptune Encounters (JPL/NASA) 1984-present Advisor of students in Caltech Summer Undergraduate Research Fellowship Program 1984-1985 ESA/NASA Science Advisory Group for Primitive Bodies Missions 1985-1993 ESA/NASA Comet Nucleus Sample Return Science Definition Team (Deputy Chairman, U.S.
  • Asteroid Regolith Weathering: a Large-Scale Observational Investigation

    Asteroid Regolith Weathering: a Large-Scale Observational Investigation

    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2019 Asteroid Regolith Weathering: A Large-Scale Observational Investigation Eric Michael MacLennan University of Tennessee, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Recommended Citation MacLennan, Eric Michael, "Asteroid Regolith Weathering: A Large-Scale Observational Investigation. " PhD diss., University of Tennessee, 2019. https://trace.tennessee.edu/utk_graddiss/5467 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Eric Michael MacLennan entitled "Asteroid Regolith Weathering: A Large-Scale Observational Investigation." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Geology. Joshua P. Emery, Major Professor We have read this dissertation and recommend its acceptance: Jeffrey E. Moersch, Harry Y. McSween Jr., Liem T. Tran Accepted for the Council: Dixie L. Thompson Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Asteroid Regolith Weathering: A Large-Scale Observational Investigation A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Eric Michael MacLennan May 2019 © by Eric Michael MacLennan, 2019 All Rights Reserved.
  • Leveraging Public Data to Reconstruct the Cost History of Planetary Exploration

    Leveraging Public Data to Reconstruct the Cost History of Planetary Exploration

    Leveraging Public Data to Reconstruct the Cost History of Planetary Exploration Casey Dreier Senior Space Policy Adviser The Planetary Society Motivations MSL Curiosity Press Kit: • Publicly-reported mission costs are inconsistent and lack detail • Comparisons are difficult between missions and over time Perseverance Press Kit: • A problem for both public education and advocates: • Press kit numbers are what gets reported! • How much “should” a mission cost? Voyager Press Kit: • How to interpret the total cost—is a $1B mission “expensive” or “a good deal”? • How much is a mission in the context of all planetary spending? Or all of NASA spending? Juno Press Kit: • How much of a mission cost are development, launch, and operations? What does it cost to explore the planets? Project Goals vs • Compile a complete record of mission and program costs for NASA’s robotic planetary program using public data. • Useful for public and public policy discourse: • Normalized to include accounting changes • Include all mission costs: development, launch, and all operations • Inflation-adjusted values • Provide costs by year • Easily and freely accessible Method • Primary source: NASA budget estimates provided by NASA HQ History Office • Used “actual” reported obligations • Augmented by a variety of secondary sources, in order of preference: • Official NASA statements (press releases, public briefings) • Projected values in PBRs • Reporting from high-quality news agencies • Normalizations (“gap fill” strategy): • Include all LV costs, except STS • Removed
  • PAC March 9 10 2020 Report

    PAC March 9 10 2020 Report

    NASA ADVISORY COUNCIL PLANETARY SCIENCE ADVISORY COMMITTEE March 9-10, 2020 NASA Headquarters Washington, DC MEETING REPORT _____________________________________________________________ Anne Verbiscer, Chair ____________________________________________________________ Stephen Rinehart, Executive Secretary Table of Contents Opening and Announcements, Introductions 3 PSD Update and Status 3 PSD R&A Status 5 Planetary Protection 7 Discussion 8 Mars Exploration Program 8 Lunar Exploration Program 9 PDCO 11 Planetary Data System 12 PDS at Headquarters 13 Findings and Discussion 13 General Comments 13 Exoplanets in Our Backyard 14 AP Assets for Solar System Observations 15 Solar System Science with JWST 16 Mercury Group 17 VEXAG 17 SBAG 18 OPAG 19 MEPAG 19 MAPSIT 20 LEAG 21 CAPTEM 21 Discussion 22 Findings and Recommendations Discussion 23 Appendix A- Attendees Appendix B- Membership roster Appendix C- Agenda Appendix D- Presentations Prepared by Joan M. Zimmermann Zantech, Inc. 2 Opening, Announcements, Around the Table Identification Executive Secretary of the Planetary Science Advisory Committee (PAC), Dr. Stephen Rinehart, opened the meeting and made administrative announcements. PAC Chair, Dr. Anne Verbiscer, welcomed everyone to the virtual meeting. Announcements were made around the table and on Webex. PSD Status Report Dr. Lori Glaze, Director of the Planetary Science Division, gave a status report. First addressing the President’s Budget Request (PBR) for Fiscal Year 2021 (FY21) for the Science Mission Directorate (SMD), Dr. Glaze noted that it was one of the strongest science budgets in NASA history, representing a 12% increase over the enacted FY20 budget. The total PBR keeps NASA on track to land on the Moon by 2024; and to help prepare for human exploration at Mars.
  • The Planetary Report

    The Planetary Report

    !-' Volume XIX Number 6 November/December 1999 Volume XIX On the Cover: The spring eq uinox for Mars' sou thern hemisphere arrived Table of Number 6 August 2, 1999, br in gi ng in the warm seasons of the yea r. The frosts of the southern polar cap began to retreat. As summer Contents Novem ber/December 1999 approached, so did the Mars Polar Lander (MPL), scheduled to touch down near the edge of the frost cap on December 3. What will MPL fi nd? We don't know yet, but the lander may encounter dust storms, which freque ntly blow in th is regio n. In this image, take n in late July, we see grayish-orange du st Features clouds just above the frost cap at the lower left. Image: Malin Space Science Systems/NASA 4 An Intervievv With Tim Ferris Does life exist on other worlds? How do we find it? Ifwe find it, how do we study or communicate with it? Science writer Tim Ferris addresses these questions in a new Public Broadcasting System television series about the possibility of extraterrestrial life, He shares some of hi s thoughts with The Planetary Report. Froln Over One Million Served: The 5 SETI@home Passes the Million Mark SETI@home is definitely the biggest research project The Planetary Society has ever been Editor involved with-and it just keeps getting bigger. Have you joined yet? t's hard to explore planets, really hard. 6 Assessing the Hazard: Those of us of a certain age remember The Development of the Torino Scale I How do you convey the approximate degree of danger posed by a passing asteroid to someone John F.
  • NASA and Planetary Exploration

    NASA and Planetary Exploration

    **EU5 Chap 2(263-300) 2/20/03 1:16 PM Page 263 Chapter Two NASA and Planetary Exploration by Amy Paige Snyder Prelude to NASA’s Planetary Exploration Program Four and a half billion years ago, a rotating cloud of gaseous and dusty material on the fringes of the Milky Way galaxy flattened into a disk, forming a star from the inner- most matter. Collisions among dust particles orbiting the newly-formed star, which humans call the Sun, formed kilometer-sized bodies called planetesimals which in turn aggregated to form the present-day planets.1 On the third planet from the Sun, several billions of years of evolution gave rise to a species of living beings equipped with the intel- lectual capacity to speculate about the nature of the heavens above them. Long before the era of interplanetary travel using robotic spacecraft, Greeks observing the night skies with their eyes alone noticed that five objects above failed to move with the other pinpoints of light, and thus named them planets, for “wan- derers.”2 For the next six thousand years, humans living in regions of the Mediterranean and Europe strove to make sense of the physical characteristics of the enigmatic planets.3 Building on the work of the Babylonians, Chaldeans, and Hellenistic Greeks who had developed mathematical methods to predict planetary motion, Claudius Ptolemy of Alexandria put forth a theory in the second century A.D. that the planets moved in small circles, or epicycles, around a larger circle centered on Earth.4 Only partially explaining the planets’ motions, this theory dominated until Nicolaus Copernicus of present-day Poland became dissatisfied with the inadequacies of epicycle theory in the mid-sixteenth century; a more logical explanation of the observed motions, he found, was to consider the Sun the pivot of planetary orbits.5 1.
  • Carl Sagan 1934–1996

    Carl Sagan 1934–1996

    Carl Sagan 1934–1996 A Biographical Memoir by David Morrison ©2014 National Academy of Sciences. Any opinions expressed in this memoir are those of the author and do not necessarily reflect the views of the National Academy of Sciences. CARL SAGAN November 9, 1934–December 20, 1996 Awarded 1994 NAS Pubic Welfare Medal Carl Edward Sagan was a founder of the modern disci- plines of planetary science and exobiology (which studies the potential habitability of extraterrestrial environments for living things), and he was a brilliant educator who was able to inspire public interest in science. A visionary and a committed defender of rational scientific thinking, he transcended the usual categories of academia to become one of the world’s best-known scientists and a true celebrity. NASA Photo Courtesy of Sagan was propelled in his careers by a wealth of talent, By David Morrison a large share of good luck, and an intensely focused drive to succeed. His lifelong quests were to understand our plane- tary system, to search for life beyond Earth, and to communicate the thrill of scientific discovery to others. As an advisor to the National Aeronautics and Space Administration (NASA) and a member of the science teams for the Mariner, Viking, Voyager, and Galileo missions, he was a major player in the scientific exploration of the solar system. He was also a highly popular teacher, but his influence reached far beyond the classroom through his vivid popular writing and his mastery of the medium of television. The early years Born in 1934, Sagan grew up in a workingclass Jewish neighborhood of Brooklyn, New York, and attended public schools there and in Rahway, New Jersey.
  • The Planetary Report

    The Planetary Report

    Board of Directors CARL SAGAN BRUCE MURRAY President Vice President Where Next for The Planetary Society? Director, Laboratory Professor of for Planetary Studies, Planetary Science, by Bruce Murray Cornell University California Institute LOUIS FRIEDMAN of Technology Dr. Bruce Murray, Vice President of The Planetary Society, spoke at the Society's commemoration of Executive Director HENRY TANNER JOSEPH RYAN Assistant Treasurer, the flight of Mariner 2, the first spacecraft to encounter another planet, held last December in o 'Melveny & Myers California Institute Washington, DC The following remarks have been taken from his address: ofT echnology Board of Advisors The first exploration of Venus by Mariner 2 was important enough to warrant our gathering here in DIANE ACKERMAN SHIRLEY M . HUFSTEDLER ~ Washington twenty years later to commemorate it. The Planetary Society exists to continue that kind poet and author educator and jurist of human achievement into the future. Tonight I would like to talk briefly about the present status of the ISAAC ASIMoV JAMES MICHENER Society and to convey some thoughts on its future direction. author author What is The Planetary Society? You read about it in The Planetary Report, but really, what is it? RICHARD BERENoZEN PHILIP MORRISON Well, to me, it is foremost an intercommunicating network of diverse individuals who are bound President. Institute Professor, American University Massachusetts together by a powerful unifying belief: that reaching out to explore our solar system and other solar Institute of Technology JACQUES BLAMoNT systems in search of our analogs is a good thing to do. Chief Scientist, PAUL NEWMAN People come to that belief in many ways.
  • The Planetary Report

    The Planetary Report

    The On the Cover: Volume XVIII Deer fihd repose in a bucolic alpine meadow nestled in Olympic Table of National Park. But such scenes of seeming security and timeless­ Number 3 ness are illusory-as the dinosaurs discovered 65 million years May/June 1998 ago when.a comet or asteroid impact wiped them out Earth Contents resides in a swarm of smaller bodies, many with the potential to wreak havoc on civilization. We have discovered about 10 percent of the near-Earth objects, but one of th e many unknown objects may at any time appear and pass through our ne ighborhood- Features as did comet Hyakutake just last year. Such as-yet -undiscovered Opinion: co mets may pose the greatest danger to life as we know it. 4 The Green Space Project Deer photo: J. Lotter, Tom Stack & Associates To many of us, an alliance of our forces with those ofthe environmental movement has Comet Hyakutake: Johnny Horne seemed a natural thing to create. But not everyone feels that way. Noted science fiction author and Planetary Society member Kim Stanley Robinson explores this dilemma. 6 Deep Space 1: FroID Exploration Technology for the 21 st Century "Faster, better, cheaper" is the new and unofficial motto of NASA. The agency's New The Millennium program is soon to test the effectiveness of that motto in guiding technology Editor development with the launch of Deep Space 1. 9 The Mars Rock: SOlne of Its Chelnistry Is Froln Earth t may not be explicit, but there is a theme In August 1996 the announcement that scientists from NASA and Stanford University had I running through this issue: life on Earth found possible traces of ancient life on Mars touched off a flurry of experimentation and and its relationship to chunks of ice and controversy.