Did Mars once have martians?

McKay, C. P.

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NASA NTRS · 20040089521

Did Mars once have martians?

McKay, C. P.

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Abstract

Pictures of Mars from the Viking and Mariner 9 missions provide evidence of liquid water in Mars' past, indicating a warmer climate. It is speculated that outflow channels and valley networks were formed 3.5 to 4 billions years ago, at the same time life was developing on Earth. Current theories suggest that chemical reactions in Mars' early atmosphere depleted the original amounts of carbon dioxide with no mechanism to recycle it back into the atmosphere. Ecosystems in the cold, dry Antarctic valleys provide models of Mars on Earth and indicate that if life evolved on Mars there may be organic or fossil evidence under the surface. Lake beds on Mars surface are considered to be the best place to hunt for fossils.

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NASA Center ARC NASA Discipline Exobiology Mars Evolution, Planetary Extraterrestrial Environment Exobiology Climate Water Greenhouse Effect Antarctic Regions Fossils Carbon Dioxide/analysis Spacecraft Ecosystem Atmosphere

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McKay, C. P.. 1993-09-01. Did Mars once have martians?. https://ntrs.nasa.gov/citations/20040089521

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