The Planetary Report — May-June 2007
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The PLANETARYPLANETARY REPORT REPORT Volume XXVII Number 3 May/June 2007 Examining Mars From The Editor On the Cover: admit it—I’m not objective about SETI@home. The Mars Exploration Rovers, Spirit and Opportunity, were designed to last three I My feelings for this scientific research project are months on the surface of the Red Planet. Three years and more than 180,000 close to maternal. images of Mars later, these hardworking robotic explorers are still making thrilling When David Anderson and Dan Werthimer, the proj- discoveries. Opportunity’s Panoramic Camera (Pancam) imaged these sand dunes ect’s leaders, came to us with their proposal, not every- at the bottom of Endurance crater on sol (Martian day) 211. Some of these dunes one here could see what to me was glaringly obvious: are more than a meter tall from crest to trough. The image is processed in false even if it was audacious and revolutionary, SETI@home color for mineral analysis. Image: NASA/JPL/Cornell University could involve the public in scientific research on the widest scale ever. So, when the response was leaning toward “No,” Background: I declared that “No” was not an appropriate answer, Once the Mars Exploration Rover Opportunity finished exploring Endurance crater, twisted arms every which way, and with a few stout- it drove south to examine how the discarded heat shield it had used during land- hearted cohorts found the start-up money. The SETI@ ing had weathered. Next to the heat shield was a rock—the only one for kilome- home project now acknowledges The Planetary Society’s ters around. Opportunity determined it to be an iron meteorite, and although Spirit role by calling our group its “founding sponsor.” has found two others since then, this is the first meteorite ever discovered on Of course, when all this started, we had no inkling another planet. Image: NASA/JPL/Cornell University of how big SETI@home could get, guessing that maybe a few hundred thousand people would volunteer their personal computers to search for a sign of extraterres- trial intelligence—which shows you can sometimes set your expectations far too low. More than 5.5 million people signed up for SETI@home—public participation beyond our wildest dreams. Now we’re seeing another spectacular return on investment in the form of spin-offs. When undertaking any project, one can hope for but not count on spin-offs. Once again, SETI@home exceeded any reasonable expectation. In this issue, you’ll read how SETI@home spawned research projects around the world that are now seeking cures for cancer, modeling climate change, The Planetary Report (ISSN 0736-3680) is published bimonthly at the editorial offices of The Planetary Society, 65 North Catalina Avenue, Pasadena CA 91106-2301, 626-793-5100. It is available to members of The Planetary Society. Annual dues in the United and in many other ways working to improve life on States are $30 (U.S. dollars); in Canada, $40 (Canadian dollars). Dues in other countries are $45 (U.S. dollars). Printed in USA. Third-class postage at Pasadena, California, and at an additional mailing office. Canada Post Agreement Number 87424. Earth. Editor, CHARLENE M. ANDERSON Copy Editor, A.J. SOBCZAK Associate Editor, DONNA ESCANDON STEVENS Proofreader, LOIS SMITH And The Planetary Society made it happen. We can Managing Editor, JENNIFER VAUGHN Art Director, BARBARA S. SMITH all be proud. Technical Editor, JAMES D. BURKE Science Editor, BRUCE BETTS Viewpoints expressed in columns and editorials are those of the authors and do not necessarily represent positions of —Charlene M. Anderson The Planetary Society, its officers, or its advisers. ©2007 by The Planetary Society. Cofounder CARL SAGAN 1934–1996 Board of Directors Chairman of the Board DAN GERACI Chairman and CEO, Club Achilles—The Iron Age President NEIL deGRASSE TYSON Astrophysicist and Director, Hayden Planetarium, American Museum of Natural History Vice President BILL NYE science educator Executive Director LOUIS D. FRIEDMAN JAMES BELL Professor of Astronomy, Cornell University HEIDI HAMMEL Senior Research Scientist and Co-Director, Research, Space Science Institute WESLEY T. HUNTRESS JR. Director, Geophysical Laboratory, Carnegie Institution of Washington Advisory Council Chair CHRISTOPHER P. McKAY planetary scientist BRUCE MURRAY Contents Professor of Planetary Science and Geology, California Institute of Technology ELON MUSK Chairman, CEO, SpaceX 4The Pioneer Anomaly— JOSEPH RYAN Executive Vice President and General Counsel, Marriott International A Mystery of Cosmic STEVEN SPIELBERG director and producer GEORGE YANCOPOULOS Proportions President, Regeneron Research Laborabories and Chief Scientific Officer by Bruce Betts International Council ROGER-MAURICE BONNET Executive Director, 6 Searching for E.T. and International Space Science Institute YASUNORI MATOGAWA Associate Executive Director, the Cure for Cancer Japan Aerospace Exploration Agency RISTO PELLINEN Director of Science in Space Research, by Amir Alexander Finnish Meteorological Institute and Charlene M. Anderson Advisory Council BUZZ ALDRIN RICHARD BERENDZEN 16 Spirit and Opportunity— JACQUES BLAMONT RAY BRADBURY Martian Geologists DAVID BRIN FRANKLIN CHANG-DIAZ by Matt Golombek ARTHUR C. CLARKE FRANK DRAKE OWEN GARRIOTT GARRY E. HUNT 17 World Watch BRUCE JAKOSKY THOMAS D. JONES SERGEI KAPITSA 18 We Make It Happen! CHARLES E. KOHLHASE JR. LAURIE LESHIN 20 Questions and Answers JOHN M. LOGSDON JON LOMBERG 22 Society News HANS MARK JOHN MINOGUE ROBERT PICARDO JOHN RHYS-DAVIES KIM STANLEY ROBINSON DONNA L.SHIRLEY Contact Us Mailing Address: The Planetary Society, 65 North Catalina Avenue, Pasadena, CA 91106-2301 General Calls: 626-793-5100 Sales Calls Only: 626-793-1675 E-mail: [email protected] A World Wide Web: http://planetary.org PUBLICATION OF 3 THE PLANETARY REPORT MAY/JUNE 2007 o one noticed the clues at first. Then, scientists PCs. That has turned out to be a challenging and time- began to notice that things just weren’t right for consuming, but surmountable, task. Below is an update Ntwo Earth spacecraft visiting a dark and nearly on the status of the data recovery and the mystery that deserted neighborhood of the solar system—mysterious- is the Pioneer anomaly. ly, the spacecraft were slowing down. What cosmic per- petrator was behind this dark deed? To help solve the A Cold Case mystery, Planetary Society members and supporters have Until The Planetary Society got involved with Slava helped turn up and preserve more evidence that may lead Turyshev and John Anderson from the Jet Propulsion to the discovery of an everyday answer to this deep space Laboratory, analysis of the Pioneer anomaly was per- detective story—or may point a finger at a gravitational formed with just 11.5 years of Pioneer 10 data, covering kingpin never before suspected. heliocentric distances from 40 to 70 AU (1 AU is the The Pioneer anomaly—the slowing of the Pioneer 10 mean distance of Earth from the Sun, about 150 million and Pioneer 11 spacecraft relative to what would be ex- kilometers or 93 million miles), and with only 3.75 years pected from basic gravitational physics—has turned into of Pioneer 11 data for heliocentric distances from about a physics detective story. Will it have a surprise ending? 20 to 32 AU. For the analysis, researchers used Doppler We don’t know yet, but we are closer to finding out. data—velocity data derived from the Doppler shift of What was needed first was more evidence, and Plane- the received frequency of the Pioneer signal. tary Society members came to the rescue when data The Pioneer anomaly effect is very small, but it is from the Pioneer spacecraft were in danger of destruc- big enough to be well within measurement limits and tion. The next obstacle was that of dealing with 30 years in fact has now been confirmed by seven independent of data collected during a period when computer tech- groups using that original set of data. Its cause, however, 4 nology transitioned from punch cards to mainframes to remains a cosmic mystery. Is it some aspect of the space- THE PLANETARY REPORT MAY/JUNE 2007 y r craft (for instance, heat radiating preferentially in one Some of the recovered data were incompatible with cur- o • t a v r e direction)? Or, less likely but a real possibility with more rent navigation software architecture, leading to problems s b O n r profound implications, could it be some new subtlety in with radio band identifications. e h t u o our understanding of physics? To even begin work on • During some periods, the data showed the presence of S n a e p solving the mystery, more data were needed for analyses. an artifact due to inappropriate data handling. o r u E : In combination, these problems meant that experts had e g a m I Saving the Evidence to look at each individual file, identify the particular prob- . ) r a The Planetary Society stepped in and funded the initial ef- lems associated with it, and make the appropriate fixes. t l A e forts to recover and validate as much Pioneer data as pos- h t ( a sible. The data recovered included not only the Doppler Picking Up the Trail r A n data but also information about the spacecraft themselves Our team has cleaned up many of the early Pioneer 11 o i t a l in what are called Master Data Records (MDRs). The files, enough to begin analyzing them. Meanwhile, the l e t s MDRs include temperature measurements of many parts rest of the Pioneer files are slowly being turned into useful n o c of the spacecraft taken over time, which will be critical to files that can soon be used to determine the direction of e h t n understanding if the anomaly has a thermal cause.