Planetary Science Seminar winter-2013

Mars was probably most habitable during an interval that began with the decline of heavy bombardment about 3.8 billion years ago and ended with the disappearance of widespread, persistent liquid surface water about 3.4 billion years ago. Given the controversial nature of biosignatures in rocks of equivalent age on Earth, satisfactory evaluation of putative Martian biosignatures from this period of maximum habitability will require sample return. Current understanding about the production, preservation, and detection of stable isotopic bio- and environmental signatures in ancient Earth rocks will be discussed in light of their relevance to future analysis of samples returned from Mars.