Space

Study suggests where to hunt for fossils on Mars

Study suggests where to hunt f...
Sedimentary rocks in Mars' Gale Crater, which is thought to have once contained a lake
Sedimentary rocks in Mars' Gale Crater, which is thought to have once contained a lake
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Sedimentary rocks in Mars' Gale Crater, which is thought to have once contained a lake
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Sedimentary rocks in Mars' Gale Crater, which is thought to have once contained a lake

Although Mars appears to be an arid, lifeless place now, about four billion years ago its surface was covered with bodies of water – which may have supported microscopic aquatic life. A new study has determined what type of rocks may be most likely to contain the fossilized remains of such microbes.

The study was conducted by scientists from Scotland's University of Edinburgh, along with American colleagues from NASA's Jet Propulsion Laboratory, Brown University, California Institute of Technology, Massachusetts Institute of Technology (MIT) and Yale University.

They determined that sedimentary rocks, which formed out of compacted mud or clay, "are the best place to seek fossil evidence of life." This is due partially to the fact that the rocks formed in ancient lake beds, during the Noachian and Hesperian periods of Martian history, between three and four billion years ago. Additionally, such rocks are rich in iron and silica, both of which are known to help preserve fossils.

If there are fossil-containing sedimentary rocks on Mars, they are more likely to be intact than their same-aged counterparts on Earth. This is because unlike our planet, Mars hasn't been subject to the shifting of tectonic plates, which can grind up ancient rocks over long periods of time.

It is now hoped that the findings could help determine the landing and search sites for future rover missions, including NASA's Mars 2020 Mission, which will be specifically looking for evidence of past Martian life.

Source: University of Edinburgh

2 comments
bwana4swahili
"... between three and four billion years ago." This should keep a debate going for years over whether they're actually fossils or naturally occurring phenomenon!
Douglas Bennett Rogers
Discovery of life on Mars would show that life is not unique to Earth. People have lost sight of the magnitude of this discovery.