Volu me XV On the Cover: Table of Number 4 Neptune ha ng s on Triton's horizo n in this thre e­ dimension al view created from Voyager image s. Jul y/Au gust 1995 Whil e this view is dramatic, it isn 't what an Contents expl ore r wou ld actual ly see whi le flyi ng over Triton : The rel ief has been exag gerated about 30 times . In the foreground are Triton's maria ("seas"), with terraces testifying to several epi sodes of volcanic flood in g- on ly the floods were of molten ice, not rock. Voyagers greatest leg acy is that the spacec raft reveal ed strange Features 16 Basics of worlds such as this to us for the fi rst time . Spacefl ight: Image: United States Geological Survey, Flagstaff What's NelN, Voyager: Making T racks 4 The Discoveries There are few landmarks and signposts in Continue space, so how do people stuck on Earth Launched nearly two decades ago, the guide a spacecraft to its destination? We Frown Voyager spacecraft still have much to teach tackle that question with a short discussion us. Data from the six planetary encounters on determining speed and position, and The continue to be mined for more discoveries, navigating in space. and the spacecraft go on operating, search­ Editor ing now for the edge of our solar system. 18 NelNs and RevielNs Journey to the End NASA was created to expand the bound­ A. s we go to press, NASA is fac­ 10 of the Dinosaur Era: aries of science into the solar system and what could be the greatest ~ng A Society Expedition beyond. But the budget cuts now proposed crisis in its existence. As you'll read in to Belize for the agency will squeeze planetary sci­ World Watch, the agency is threatened Planetary science has laid claim to the entists past the point of simple discomfort. with budget cuts that could destroy its solution of one of the most perplexing Many of the best are leaving the field, as vitality. Ifthe budget proposed by the mysteries of the natural world: What killed our faithful colunmist-himself a planetary United States House of Representatives off the dinosaurs? An extraterrestrial object scientist-reports. becomes reality, what survives as is now the leading suspect, and here we NASA may be a pale shadow of the report on a Planetary Society expedition 19 Societ y agency that took us to the planets. in search of evidence in the investigation. NelNs Another agency of explorers is in even While others critique the new information more danger: Some in Congress are technology, the Society is using it: We're threatening to eliminate the US Geolog­ Departl'l1lent s holding an on-line conference with the ical Survey. Through its branch of astro­ leaders of our Belize expedition. We're also geology, the USGS is a major force in 3 Member s' forging ahead with our Red Rover, Red planetary exploration, and its loss Dial ogue Rover project, holding a space science would be a body blow to those endeav­ Mining the Moon, a perennially hot topic, workshop with the United Nations and has again generated debate among our ors supported by The Planetary Society. the European Space Agency, preparing to members. Our rover project with the Jason Things are worse in Russia. Mars celebrate Galileo's arrival at Jupiter and Foundation and our support for a Pluto publishing another newsletter. Plus, our Together, the program supported by the mission have also prompted letters. members have met the Micron challenge! Society, appears to be in trouble. The Russian Space Agency just doesn't World Questions and have enough money for all its projects. 20 15 Watch AnslNers This year could mark a downward NASA is under fire from budget-cutters, Radiation belts surround many of the turn in planetary exploration. What can which is a not uncommon occurrence, but worlds in our solar system, affecting their you do to stop it? First, let your govern­ this time the attack could be devastating. interactions with the pervasive solar wind. ment know that you support planetary Adding to the trouble is a delay in the We explore those regions and revisit the exploration. Then reaffirm your support Mars Together program. It is truly a time collision of comet Shoemaker-Levy 9 of the Society. Our voices joined will of crisis in planetary exploration. with Jupiter. be more effective in the fight to preserve Earth's ability to explore the planets. - Charlene MAnderson The Planetary Report (ISSN 0736-3680) is published bimonthly at the editorial offices of The Planetary Society, ~5 North Catalina Avenue, Pasadena, CA 91106-2301 , 818-793-5100. It is available to members ofThe Planel.ary SC?c lety. Ann!-lal dues In the US or Canada are $25 US dollars or $30 Canadian. Dues outside the US or Canada are $35 (US). Printed In USA. Th ird-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 THE-PL.A~T1RY SOCIETY Assistant Editor, DONNA ESCANDON STEVENS Copy Editor. GLORIA JOYCE Production Editor, MICHAEL HAGGERTY Art Director, BARBARA S. SMITH o .~ -e- cP -B- 0 Viewpoints expressed in columns or editorials are tho~e of the authors and do not necessarily represent positions of The Planetary Society, its officers or advisors. © 1995 by The Planetary Society o Board of Directors CARL SAGAN President Members' Director, Laboratory for Planetary Studies, Cornell University BRUCE MURRAY Dialogue Vice President Professor of Planetary Science, California fnstitute of Technology LOUIS FRI EDMAN Executive Director NORMAN R. AUGUSTINE PreSident, Lockheed Martrn Corporation JOSEPH RYAN Executive Vice President and General Counsel, Marriott International STEVEN SPI ELB ERG director and producer Jason views on the Friends ofPluto and over the quarter of a million miles LAUREL L. WILKEN ING Chanceflor, University of California, Irvine Recently I had the pleasure of Charon concept. I would also like that separate us. attending an interactive session to point out that in 1991 we pub­ The Moon is a pristine wilder­ Board of Advisors DIANE ACKERMAN sponsored by the Jason Foundation lished a letter by Keith in Members' ness, to be sure. By the very fact poet and author BUZZ ALDRI N and The Planetary Society at a PIN Dialogue in which he suggested a of its low gravity, it will never be Apollo 11 astronaut (Primary Interactive Network site) Pluto/Charon mission using a US­ able to hold an atmosphere for RICHARD BERENDZEN near my home. (See the May/June built spacecraft and a Russian any length of time, so terraforming educator and astrophysicist JACQUES BLAMONT 1995 issue of The Planetary launch vehicle. it will never be a viable option. Chief Scientist, Centre National d'Etudes Spatia/es, France Report.) Not only was the presen­ - Louis D. Friedman, Therefore, humans must always RAY BRADBUR Y tation interesting and informative, Executive Director live underground or in small sur­ poet and author ARTH UR C. CLARKE but the student displays of data on face establishments. Even with author Hawaii, volcanism and plate tecton­ Moon Mining these and the mining efforts to CORNELIS DE JAGER Professor of Space Research, ics were well done and indicated a I read with interest the letters in support them, on the large scale The Astronomical Institute at Utrecht, the Netherlands lively interest in scientific subjects. the March/April 1995 issue of The the "magnificent desolation" will FRANK DRAKE Professor of Astronomy and Astrophysics, The final three minutes of the Planetary Report. While I agree prevail for all time. University of California, Santa Cruz presentation were devoted to the with the spirit, if not the entire -JEFFREY E. HOYLE, JOHN GARD NER Mars Rover. A 14-year-old student content, of Marge Currie's letter, San Jose, California founder, Common Cause MARC GAR NEAU got the chance to drive the rover, I take issue with that of D. Downs. Canadian astronaut and she did very well. I want to While the Moon belongs to no I was disappointed at D. Downs' GEORG IY GOLITSYN lnstitute of Atmospheric Physics, take this opportunity to thank the one in particular, it belongs to the letter in the March/April Members' Russian Academy of Sciences THEODORE M. HESBURGH Society for enabling me to take part. human race in general, by virtue Dialogue. If the Moon's resources President Emeritus, It certainly was time well spent. of the fact that Earth is its primary. belong to no one, then like all University of Notre Dame SHIRLEY M. HUFSTEDLER -EDWARD J. WARD, Hicksville, If Downs is concerned that we other resources throughout history educator and jurist New York will turn the Moon into a slag they will eventually belong to GARRY E. HUNT space scientist, United Kingdom heap, I say that it is already a slag whoever puts them to use or SERGEI KAPITSA {flsutute for Physical Problems, Pluto"s Pals heap by its very nature. It has no seizes them by force. The rain Russian Academy of Sciences Viva Louis Friedman for his leg­ ecology or fragile environment. forests are being burned down for GEN . DONALD J. KUTYNA (RET.) work in lobbying NASA since Downs, as a member of the farmland by people who have no former Commander, US Space Command JOHN M. LOGSDO N 1993 to accept a joint Russian­ Society, should know better than wish to see their children starve Director, Space Policy Institute, George Washington University United States Pluto probe, using anyone that mining the Moon for and who are receiving little con­ HANS MARK each side's strengths-a Russian terrestrial benefit will never be an sideration from the "planetary The Universify of Texas at Austin JAMES MICHENER Proton arid a lightweight US space economical proposition due to community." author probe.