Question

Will the Mars rovers be able to look for fossils (gross and/or microscopic)? If so, is it part of the exploration plan?

The two rovers now operating on Mars are not equipped to search for the microscopic fossils that are thought to be the most likely evidence for past life on Mars. With their excellent camera systems, the rovers might indeed see a large fossil of a multicelled creature, if one should happen to be there, but this is extremely unlikely -- think how difficult it is to find macroscopic fossils an Earth, a planet where multicellular life has been abundant for hundreds of millions of years. The exploration plan for these rovers is primarily to characterize the geologic history of the environment. The are especially interested in finding evidence of sedimentary rock, particularly if such rock might have been deposited within bodies of water (which is the way most sediment on Earth is formed). Initial indication that the Opportunity rover in Meridiani Planum might be seeing layering in exposed bedrock is potentially very exciting. If these present rovers find evidence for sediment in ancient ponds or lakes, then future missions might carry instruments specifically designed to look for microfossils or even to detect extant life on Mars.

David Morrison
NAI Senior Scientist
January 30, 2004