[meteorite-list] Conditions On Vast Plain on Mars Could Have Been Suitable For Life

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Dec 2 23:47:06 2004
Message-ID: <200412030447.UAA02241_at_zagami.jpl.nasa.gov>

http://www.news.cornell.edu/releases/Dec04/Science.Mars.deb.html

Conditions on vast plain on Mars could have been suitable for life,
Cornell rover scientist Squyres states in special Science issue

FOR RELEASE: Dec. 2, 2004

Contact: David Brand
Office: 607-255-3651
E-mail: deb27_at_cornell.edu

ITHACA, N.Y. -- Scientists have long been tantalized by the question
of whether life once existed on Mars. Although present conditions on
the planet would seem to be inhospitable to life, the data sent back
over the past 10 months by NASA's two exploration rovers, Spirit and
Opportunity, showed a world that might once have been warmer and
wetter -- perhaps friendly enough to support microbial organisms.

Now a Cornell University-led Mars rover science team reports on the
historic journey by the rover Opportunity, which is exploring a vast
plain, Meridiani Planum, and concludes with this observation: "Liquid
water was once present intermittently at the martian surface at
Meridiani, and at times it saturated the subsurface. Because liquid
water is a key prerequisite for life, we infer that conditions at
Meridiani may have been habitable for some period of time in martian
history."

The article is one of 11 published this week (Dec. 3, 2004) in a
special issue of the journal Science, authored by scientists
connected with the Mars rover mission, several from Cornell and from
the Jet Propulsion Laboratory in Pasadena, Calif., the mission's
manager. The issue covers Opportunity through its first 90 days of
exploring its landing site of Eagle crater in Meridiani Planum. This
was before the rover drove to and entered the large crater dubbed
Endurance, from which it is now about to emerge.

Steve Squyres, Cornell professor of astronomy and leader of the
rovers' Athena science team, is the lead author of the main paper,
"The Opportunity Rover's Athena Science Investigation at Meridiani
Planum, Mars." In another paper, on which he is also the lead author,
Squyres again refers to the geological record at Meridiani Planum as
suggesting that conditions were suitable for "biological activity"
for a period of time in the history of mars. In the article, "In Situ
Evidence for an Ancient Aqueous Environment at Meridiani Planum,
Mars," he writes: "We cannot determine whether life was present or
even possible in the waters at Meridiani, but it is clear that by the
time the sedimentary rocks in Eagle crater were deposited, Mars and
Earth had already gone down different environmental paths. Sample
return of Meridiani rocks might well provide more certainty regarding
whether life developed on Mars."

The Mars rover mission is not designed to look for microbial life but
to look for evidence of whether conditions were once right for life.
As Squyres recently stated, "What we were seeking was rocks that were
actually formed in liquid water so that we could read the record in
those rocks, not just to say liquid water was on Mars but to learn
something about what the environmental conditions were like, would
they have been suitable for life and, importantly, do the minerals
that were formed have the capability to preserve for long periods of
time evidence of former life? That's probably the single most
important thing we have found: evidence for minerals at Meridiani
that are the kinds of things that are very good at preserving
evidence of ancient life for very long periods of time."

Opportunity bounced down on Jan. 25, 22 days after its twin, the
rover Spirit, landed on the opposite side of Mars in Gusev crater.
Last August Science published a special issue on Spirit.

"This is the first peer-reviewed presentation of the data from
Opportunity," notes Jim Bell, Cornell associate professor of
astronomy and the lead scientist for the rovers' Pancam color imaging
system.

Bell also is prominent in the special issue of Science, including his
lead authorship of a paper, "Pancam Multispectral Imaging Results
from the Opportunity Rover at Meridiani Planum."

When Opportunity landed on the red planet last January, the robot
geologist sent back images of its landing site that were unlike any
of the other places where earlier lander probes and rovers had gone.
Instead of rusty deserts of dusty soil and boulders strewn to the
horizon, Opportunity had landed in a relatively small crater in a
vast sea of sand nearly devoid of rocks. Fortunately, an intriguing
outcrop of bedrock presented itself nearby, which scientists hoped
would be a sample of the original crust underneath the layers of dust.

The scientists were not disappointed. Scattered among the outcrop
rocks were large numbers of small, round mineral deposits that the
Athena science team named "blueberries." On Earth, such formations
appear when large amounts of water course through rock layers,
leaching out the iron--bearing minerals into small spherical rocks
and granules. The rovers also detected large amounts of sulfate salt
deposits. Enough evidence was collected by Opportunity in the two
months it spent examining Eagle crater that the science team felt
confident enough to announce in early March that liquid water had
flowed over the crater's rocks long ago, possibly for a long time.
Following on this, the latest Science articles largely focus on
Opportunity's most important scientific and geological
accomplishment: the discovery of evidence that liquid water once
flowed through the region.

Like the coverage given to Spirit in the August issue of Science, the
latest edition contains several foldouts with big color panoramas and
images from Opportunity's region of exploration.

Freelance writer Larry Klaes contributed to this report.

-30-
Received on Thu 02 Dec 2004 11:47:01 PM PST