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Water and Life on MarsMars appears to be cold dry and dead world. However there is good evidence that early in its history it had liquid water, more active volcanism, and a thicker atmosphere. Mars had this earth-like environment over three and a half billion years ago, during the same time that life appeared on Earth. The main question in the exploration of Mars then is the search for a independent origin of life on that planet. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils. Although the Viking results may indicate that Mars has no life today, there is direct geomorphological evidence that, in the past, Mars had large amounts of liquid water on its surface - possibly due to a thicker atmosphere. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. One of the martian meteorites dates back to this early period and may contain evidence consistent with life. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. Ecosystems in cold, dry locations on Earth - such as the Antarctic - provide examples of how life on Mars might have survived and where to look for fossils.
Document ID
20010076249
Document Type
Preprint (Draft being sent to journal)
Authors
McKay, Christopher P. (NASA Ames Research Center Moffett Field, CA United States)
DeVincenzi, Donald
Date Acquired
August 20, 2013
Publication Date
January 15, 2000
Subject Category
Life Sciences (General)
Meeting Information
EuroConference: Origin of Life(Trieste)
Funding Number(s)
PROJECT: RTOP 344-38-82-04
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.