Life on Mars: Possible Evidence in Meteorites

Scientists of Nasa and Stanford University (California) have found evidence for fossil life in a Martian rock. This so-called SNC meteorite had been ejected into space by an asteroid impact on Mars about 15 million years ago, and travelled around the Sun on an elliptical orbit on its own, as a miniture planet, until it impacted in an antarctic ice field about 13,000 years ago, where it was found in 1984. It was labelled "Allen Hills 84001" or "ALH 84001".

What was discovered is complex organic compounds within the rock, so-called PAHs ("polycyclic aromatic hydrocarbons). The chemistry, mineralogy, and texture of these compounds and surrounding carbonates, collectively, point to a biological origin, and thus the conclusion that there is evidence for primitive life on Mars. This life is thought to have existed there billions of years ago (the carbonates are estimated at an age of 3.6 billion years), and consist of simple micro-organisms similar to terrestrial bacteria.

The claim of evidence for life depends on a number of facts which had to be examined:

• Evidence had to be established that the rock had its origin on Mars.
• It had to be checked if the organic compounds could have terrestrial origin (i.e. if they are contamination added during the 13,000 years when the rock was in the ice).
• If of Martian origin, investigations had to be performed if they had formed in biological or non-biological process.

Links

• Fossil Life in Martian Rock ? image gallery at SEDS
• Life on Mars homepage by John Pike; part of the Space Policy Project of the Federation of American Scientists (FAS):
  • Nasa statement by administrator Dan Goldin
  • Nasa News Conference Announce
  • AAAS article to be featured in Science of August 16, 1996
  • The News Conference Transcripts are no more available, unfortunately
• CNN story on the discovery of evidence for life on Mars; Life on Mars image gallery; Nasa space probes will search for life on Mars; Wesley T. Huntress (Nasa associate administrator) interview
• British present new evidence for life in a second Mars meteorite (CNN)
• Official Nasa releases:
  • Nasa News Conference Announce
  • Nasa HQ release 96-159: Statement by Nasa administrator Dan Goldin
  • Nasa HQ release 96-160: Meteorite yields evidence of primitive life on early Mars
• Nasa Release images and info:
  • http://rsd.gsfc.nasa.gov/marslife/
  • Martian Rock images presented by SEDS
• Infos on the SNC Meteorites:
  • SNC meteorite homepage (JPL)
  • Eric W. Weisstein's SNC meteorite glossary page
  • Read of evidence why these rocks are from Mars (NASM)
  • Info on the Mars rock ALH 84001 by the JSC curator
  • The LPI slideset The Red Planet, Mars Survey includes some coverage of the SNC meteorites
• The JSC curator's Mars Meteorite Compendium; Life on Mars page; D.S. McKay et.al, Search for Past Life on Mars.
• Marslife Hotnews from Jeff Foust of the Spaceviews Newsletter
• Observatorio ARVAL Marslife page [also in Spanish]
• Preprints of Magazine articles and newsflashes:
  • George Musser. The Strongest Evidence Yet for Life on Mars. Mercury magazine & ASP hotline.
  • J. Kelly Beatty. Life from Ancient Mars ? Special edition of Sky & Telescope's Weekly News Bulletin, August 8, 1996. To appear in Sky & Telescope, October 1996 issue.
  • Robert Naeye. Was There Life on Mars ? An in-depth article has appeared in the Astronomy magazine.
• Mars Meteorite papers reviewed by Allan Treiman (Lunar and Planetary Institute)
• Slide Set from the LPI: Ancient Life on Mars ?

Printed Sources

• Science, August 16, 1996: The original discovery story
• Nature
• Mercury, September/October 1996, p. 2
• Sky & Telescope, October 1996, p. 18-19
• Astronomy, November 1996, p. 46-53
• German Sterne und Weltraum, November 1996, p. 832-834

The successfully landed Mars Pathfinder and its small robotic rover Sojourner discovered evidence for large water abundances on ancient Mars in July 1997, thus supporting the possibilities of ancient life on the Red Planet. Mars Global Surveyor confirmed this evidence from Mars orbit by photographing various landforms indicating former existence of huge quantities of water on Mars in late 1997 and early 1998.

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