Searching for Life in the Solar System ... And Beyond
A Research Discussion Meeting
London, UK - 31 October 1996

SNC Meteorites, Space Probes from Mars

I P Wright, Planetary Sciences Research Institute, The Open University

SNC Meteorites are samples of rock thought to have originated on Mars -- there are currently 12 of them. One such sample, the 4.5 billion year old Allan Hills [ALH] 84001, recently hit the media headlines on account of a proposal that the meteorite contains evidence of biological microfossile. The implication is that there was once life on the planet. The microfossil evidence remains controversial; however, there are unambiguous observations that contribute information to the subject. One such area involves analysis of the carbon in SNC meteorites [i.e., carbon in all its guises, as organics, carbontes minerals, trapped martian atmospheric gases, and magmatic volatiles dissolved in minerals]. In this regard note that ALH 84001 does contain organic materials. Note also that another SNC meteorite, Elephant Moraine [EET] A79001, has organic compounds associated with carbonates. What makes this latter finding important is that EET A79001 has a formation age of about 0.2 billion years [and is "geologically" recent compared to ALH 84001]. If there really is evidence for life in ALH 84001, could there also be in EET A79001? If so, this would practically demonstrate the existence of life on Mars today.