MARSBUGS: The Electronic Astrobiology Newsletter Volume 6, Number 16, 12 June 1999. Editors: Dr. David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83844-3051, USA. Marsbugs@aol.com or davidt@uidaho.edu. Dr. Julian Hiscox, Division of Molecular Biology, IAH Compton Laboratory, Berkshire, RG20 7NN, UK. Julian.Hiscox@bbsrc.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained via anonymous FTP at ftp.uidaho.edu/pub/mmbb/marsbugs or at the official Marsbugs web page at http://members.aol.com/marsbugs/marsbugs.html. The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer-reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come out of the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. ------------------------------------------------------------------ CONTENTS 1) MARTIAN ORGANIC MATTER IN ALH84001? By G. Jeffrey Taylor 2) MARS GLOBAL SURVEYOR STATUS REPORT JPL release 3) THIS WEEK ON GALILEO JPL release 4) MARS SURVEYOR 98 MISSION STATUS JPL release ------------------------------------------------------------------ MARTIAN ORGANIC MATTER IN ALH84001? By G. Jeffrey Taylor, Hawaii Institute of Geophysics and Planetology From Planetary Science Research Discoveries (http://www.soest.hawaii.edu/PSRdiscoveries) 3 June 1999 A recent paper by Luann Becker, Brian Popp, Terri Rust (all at the University of Hawaii), and Jeffrey Bada (University of California, San Diego) claims to have the first definitive evidence for the presence of martian organic compounds in martian meteorite ALH84001, the famous meteorite that may or may not have fossils in it. They do not think that these organic compounds reflect biological processes on Mars. There is plenty of organic matter in this meteorite, but many investigators have claimed that most of it entered the rock after it fell to Earth. Tim Jull and his associates, for example, estimated that 80% of the organic carbon in the meteorite was from the Earth (see PSR Discoveries article Organic Compounds in Martian Meteorites May be Terrestrial Contaminants). Although Jull's work emphasized the importance of the contamination problem, it also left room for the presence of organic matter that came from Mars. Becker and her colleagues wanted to investigate the nature of that potentially-martian material. Using only 0.46 grams of ALH84001, they carried out a series of experiments in which they dissolved the carbonates, a main carrier of organic compounds, and measured the carbon isotopic compositions of the solutions and the left over, undissolved rock. The carbon associated with the carbonate globules had carbon-12/carbon-13 ratios like terrestrial organic carbon, and they consider it to be terrestrial contamination. They support this interpretation by pointing out Jull's work and previous work reported by Jeff Bada (see PSR Discoveries article Life on Mars--The Debate Continues), which also suggest contamination. The samples from which carbonate minerals had been removed, however, had carbon-12/carbon-13 ratios less than the standard terrestrial value, and Becker believes that this organic matter is probably indigenous to the rock, hence is from Mars. Becker also made more direct measurements of the organic compounds in ALH84001. Using Laser Desorption Mass Spectrometer (LDMS), she fired a finely-focused laser at acid-treated carbonate globules and silicate mineral grains. Besides the usual polycyclic aromatic hydrocarbons (also known as PAHs), she found very heavy carbon compounds, with masses like that of heavy organic compounds called kerogens. Similar kerogen-like material in the Murchison carbonaceous chondrite has similar characteristics, including the same carbon-12/carbon-13 ratio. This similarity leads Becker and coworkers to suggest that the indigenous organic compounds in ALH84001 may be from meteorite bombardment of the surface of Mars. They do not think that the organic compounds in ALH84001 reflect biological processes on Mars. An extra-Martian source of the organic compounds would overcome a problem: the surface of Mars is too oxidizing to allow synthesis of organic compounds, according to Becker and co-workers. They cite recent studies by J. Farquhar and others (University of California, San Diego), which indicate that the surface of Mars is highly oxidizing. A rain of organic-rich debris, however, would be buried over time by being incorporated into sedimentary deposits, which would protect them from the oxidizing conditions at the surface. This may be how the raw ingredients for life were deposited on Mars, and perhaps on Earth as well. Whether the organic compounds in ALH 84001 are biological or not, this work, coupled with Jull's observation that 20% of the organic compounds in ALH84001 could be extraterrestrial, shows that organic compounds are present on Mars. Whether their presence led to life or not remains to be seen. Articles referenced in this story Becker, L., B. Popp, T. Rust, and J. L. Bada, 1999, The origin of organic matter in the martian meteorite ALH84001. Earth and Planetary Science Letters, 167:71-79. Farquhar, J., M. H. Thiemens, T. Jackson, 1998, Atmosphere-surface interactions on Mars: delta O17 measurements of carbonate from ALH84001. Science 280:1580-1582. Useful links for this story Organic compounds in martian meteorites may be terrrestrial contaminants http://www.soest.hawaii.edu/PSRdiscoveries/Feb98/OrganicsALH84001. html Life on Mars--the debate continues http://www.soest.hawaii.edu/PSRdiscoveries/Mar97/LifeonMarsUpdate. html The original story can be found at http://www.soest.hawaii.edu/PSRdiscoveries/June99/organicsBecker.h tml. ------------------------------------------------------------------ MARS GLOBAL SURVEYOR STATUS REPORT JPL release 3 June 1999 Last Orbit Covered by this Report = 1062 Total Orbits = 2744 Total Mapping Orbits = 1062 Sequencing The first science campaign has completed successfully. The mm004 sequence is now active and will control nominal mapping operations through June 30. HGA Anomaly The HGA gimbal is currently operational with full redundancy on side-A. The fault protection threshold for HGA stuck gimbal is at 25 seconds (50 counts). Spacecraft Events All subsystems are reporting nominal status. No further change has been detected in the IMU gyro currents and all performance remains nominal. Uplinks There have been 14 uplinks to the spacecraft during the last week, including the mm004 sequence, new star catalog and ephemeris files, and instrument command loads. Total command files radiated to the spacecraft since launch is 3709. Upcoming Events A second test to temporarily interrupt the solar array auto- tracking for TES troubleshooting will be executed on 6/8/99 at 13:45:00 UTC. OTM-2 is scheduled for 6/10/99. The exact burn time will be determined early next week. The purpose of this OTM is to set the ground track spacing to the desired amount. ------------------------------------------------------------------ THIS WEEK ON GALILEO JPL release 7-13 June 1999 Galileo spends this week retrieving stored data from its onboard tape recorder and then processing, packaging, and transmitting the data to Earth. This week's data contains observations made by the spacecraft's solid-state imaging camera, near-infrared mapping spectrometer, photopolarimeter radiometer, and suite of fields and particles instruments. The observations contain information describing Callisto, Io, Europa, Jupiter's atmosphere and magnetosphere and the Io torus, and were acquired during Galileo's previous encounter in early May. During the first part of the week, the solid-state imaging camera returns three observations of Callisto. The first contains a dark feature that is believed to be a cryovolcanic flow and could provide evidence of ancient volcanism. The second consists of images of cratered terrain. It is designed to gather statistics on the size distribution of craters on Callisto's surface and will help scientists estimate the age of Callisto's surface. The third is an image of Bran crater, a young, single-ring crater that provides a good view of Callisto's crust. The near-infrared mapping spectrometer also returns an observation of Bran crater to provide information on the chemical composition and variation of the region. In other observations, the near-infrared mapping spectrometer returns measurements of the chemical composition of two different regions. In the latter part of the week, the spacecraft continues playback with a second pass through the data stored on the tape recorder. This second opportunity at playback allows the replay of data lost in transmission to Earth, reprocessing of data using different parameters, or return of additional new data. During this time, the near-infrared mapping spectrometer returns measurements of the surface composition in the region near the Prometheus volcano on Io, and an observation of Europa taken while it was in Jupiter's shadow. The photopolarimeter radiometer returns an observation, which was designed to find small temperature variations within one of Jupiter's cloud belts. The near-infrared mapping spectrometer continues with playback by returning three observations of a turbulent region in the wake of the Great Red Spot, and one observation of a hot spot region. The fields and particles instruments return data to fill in gaps in their measurements of the plasma and magnetic and electric fields of the Io torus. And finally, the solid-state imaging camera returns a series of images showing the evolution of atmospheric waves along the equator and cloud motions in Jupiter's north and south equatorial belts, and in a high speed jet in the northern hemisphere. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at http://www.jpl.nasa.gov/galileo. ------------------------------------------------------------------ MARS SURVEYOR 98 MISSION STATUS JPL release 10 June 1999 Mars Climate Orbiter (MCO) During the early morning all of the software updates and command sequences needed for the "All-Stellar" mode demonstration were transmitted to the spacecraft successfully (28 command files in all). The flight team will conduct the demonstration tomorrow afternoon (Friday June 11) during a tracking pass over Deep Space Station 65 at the Deep Space Network complex near Madrid, Spain. The Stanford University team, which supported last month's UHF radio test, using the University's 40-meter radio telescope near Palo Alto, California, has confirmed successful detection of the Mars Polar Lander acquisition signal transmitted during the test period. With this milestone complete, all of the objectives for this test have been achieved. Mars Polar Lander (MPL) The MPL spacecraft continues to perform well in cruise. On the ground, the flight team accomplished the first successful test run of a "proto-flight" version of the landing day, or Sol 0, command sequence in the MPL simulator. This test also marked the first successful system test in which the MCO simulator was simultaneously executing a proto-flight UHF contact sequence, with communication occurring between the UHF transceivers installed in each simulator. Once a target landing site is finalized later this summer, leading to determination of the exact time of landing, these proto-flight command sequences will be updated to flight status with the correct timing. For more information on the Mars Surveyor 98 missions, please visit our web site at http://mars.jpl.nasa.gov/msp98. ------------------------------------------------------------------ End Marsbugs Vol. 6, No. 16