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PARIS: Water bathed the surface of southern Mars for millions of
years, helping to create an environment theoretically capable of
nurturing life, according to a new study into the planet’s
mysterious oceans.
Scientists at Brown University on Rhode Island
used an instrument aboard a US spacecraft, the Mars Reconnaissance
Orbiter, to hunt for traces of phyllosilicates or clay-like minerals
that preserve a record of water’s interaction with rocks.
They found phyllosilicates in thousands of
places, in valleys, dunes and craters in the ancient southern
highlands, pointing to an active role by water in Mars’s earliest
geological era, the Noachian period, 4.6 to 3.8 billion years ago.
“These results point to a rich diversity of
Noachian environments conducive to habitability,” the authors
conclude.
An intriguing find was of deposits in the
pointed peaks at the center of craters. These peaks are generally
taken to be underground material thrown up by an impacting asteroid
or comet.
For water to be present in such peaks, it must
have been present as much as five kilometers (three miles) below the
planet’s surface, the paper suggests.
The subsurface phytosillicates were formed at
relatively low temperatures, of between 100 degrees celsius and 200
degrees celsius, which imply that Mars was not only wet but also
relatively temperate at the time.
-- AFP
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