[FPSPACE] primoridal Mars was just like primordial Earth

[Peter Pesavento]

"Mars was much more Earth-like than it is today," said Bell. "We don't know
if it was a living planet, but there would have been lakes, ponds, rivers,
snowfall and glaciers." 

http://blog.wired.com/wiredscience/2008/08/primordial-mars.html

 

Primordial Mars Resembled Primordial Earth

By Brandon Keim August 07, 2008 | 1:40:17 PM

 

The layering of minerals in an ancient Martian riverbed channel suggests
that primordial Mars resembled primordial Earth, and may have been just as
suitable for life. 

The analysis, based on data returned by the Mars Reconnaisance Orbiter and
published today in Science, is perhaps the most exciting in a string of
recent red planet findings. 

"The environment was probably habitable as we define it," said Jim
<http://marswatch.astro.cornell.edu/resume.html%20>  Bell, a specialist in
Martian geology who was not involved in the study. "If there were any life
forms, they would have been in an environment conducive to their survival,
even their thriving." 

In June, stunning time-lapse images of evaporating ice verified
<http://blog.wired.com/wiredscience/2008/06/mars-phoenix-tw.html%20>  the
long-suspected presence of Martian water. Scientists soon reported that
Martian water was once widespread
<http://blog.wired.com/wiredscience/2008/07/water-water-eve.html%20> ,
playing a central role in the planet's development. Earlier this week, NASA
announced
<http://blog.wired.com/wiredscience/2008/08/liveblog-nasa-p.html%20>  the
discovery of perchlorate, a molecule metabolized by some Earthly bacteria.

Today's study describes Mawrth Vallis, a channel cut 3.5 billion years ago
by water flowing through the Noachian highlands of Mars' southern
hemisphere. Geologists found extensive deposits of a type of iron that -- at
least on Earth -- is formed by the weathering of volcanic rocks by water,
and is known for supporting bacterial life.

"On Earth, if this type of iron is around, then bacteria use it," said said
study co-author John Mustard, a Brown University geologist.

Even more tantalizing, Mustard's team found layers of clay minerals likely
formed by the long-term leaching of water through the iron. "The geometric
relationships," said Mustard, "imply a lot of water. Rainfall." That, said
Bell, implies higher temperatures that could only be provided by an
atmosphere.

"Mars was much more Earth-like than it is today," said Bell. "We don't know
if it was a living planet, but there would have been lakes, ponds, rivers,
snowfall and glaciers." 

Both researchers cautioned that the layering could be a geological
coincidence, but favored water as the explanation. And with water, warmth
and basic minerals provided, the last piece needed for life as we know it is
carbon-bearing organic molecules. Those could easily have been deposited by
meteors that peppered Mars during its infancy, said Mustard.

Scientists have suggested that meteors
<http://www.wired.com/science/space/news/2008/08/galactic_panspermia>  also
delivered life-starting molecules to Earth, and Mustard noted that the clays
of Mawrth Vallis could bond easily with organics, creating a fertile stew of
life's ingredients.

The key question now, said Bell, is whether these conditions existed long
enough to support life's emergence. 

"If it was a flash in the pan, it may not have been enough time for complex
chemistry and the formation of life and evolution to appear," he said. "But
if it was a billion years, or just many hundreds of millions, you get into
the same situation we believe early Earth was in. And once the environment
formed on early Earth, life followed quickly."

Phyllosilicate <http://www.sciencemag.org/current.dtl>  Diversity and Past
Aqueous Activity Revealed at Mawrth Vallis, Mars [Science] [not yet online]

 

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