[meteorite-list] Hunting Martian Fossils Best Bet For Locating MarsLife

From: Dave Freeman mjwy <dfreeman_at_meteoritecentral.com>
Date: Fri, 23 Feb 2007 09:07:44 -0700
Message-ID: <45DF1150.6020304_at_fascination.com>

Dear Sterling;
After hunting them here very successfully for 9 (wow that's a very long
time) years, I am pretty good at it.
Track record: stromatolites found 6 separate genus and species, 8 tons
collected
                        meteorites: found 1 L-6
           54 grams
 For hire: middle aged stromatolite prospector Has not flown in 31
years. ...another case of astronaut farmer.
Dave F.


Sterling K. Webb wrote:

>Hi, List,
>
>
>
>>discovery may involve finding biologically
>>formed structures in old sedimentary deposits...
>>like stromatolites found here on Earth.
>>
>>
>
> I say we get up a kitty to send Dave Freeman!
>
> Mars is a lot like Wyoming, Dave, only redder.
>
>
>Sterling K. Webb
>-------------------------------------------------------------
>----- Original Message -----
>From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
>To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
>Sent: Friday, February 23, 2007 1:01 AM
>Subject: [meteorite-list] Hunting Martian Fossils Best Bet For Locating
>MarsLife
>
>
>
>
>College of Liberal Arts and Sciences
>Arizona State University
>Tempe, Arizona
>
>Media contacts:
>Skip Derra, (602) 510-3402
>Robert Burnham, (480) 458-8207
>
>Source:
>Jack Farmer, (480) 560-1764
>
>Feb. 16, 2007
>
>Hunting Martian fossils best bet for locating Mars life, says ASU researcher
>
>SAN FRANCISCO, Calif. -- Hunting for traces of life on Mars calls for two
>radically different strategies, says Arizona State University professor Jack
>Farmer. Of the two, he says, with today's exploration technology we can most
>easily look for evidence for past life, preserved as fossil "biosignatures"
>in old rocks.
>
>Farmer is a professor of geological sciences in ASU's School of Earth and
>Space Exploration, where he heads the astrobiology program. He is reporting
>on his work today (Feb. 16) at the annual meeting of the American
>Association for the Advancement of Science in San Francisco.
>
>"Searching for extraterrestrial life must follow two alternative pathways,
>each requiring a different approach and tools," Farmer says. "If we're
>looking for living organisms, we are doing exobiology. But if we are seeking
>traces -- biosignatures -- of ancient life, it's better to call it
>exopaleontology."
>
>Unfortunately, he notes, "for the next 10 or 15 years, technology
>limitations will force us down the exopaleontology path." The core issue is
>accessibility. "To find living organisms on Mars," says Farmer, "you need to
>find liquid water. Because liquid water is unstable on the Martian surface
>today, that means going deep into the subsurface."
>
>Water saturates the ground in high latitudes north and south, and around
>both poles, only a few inches below the surface, Farmer explains. But this
>water remains frozen year round. "Environments with liquid water will likely
>lie far deeper, perhaps miles below the surface."
>
>Organisms have been found living in fractured rock, thousands of feet
>underground on Earth, Farmer notes. "But with current robotic technology, we
>simply can't drill that deep on Mars."
>
>Terrestrial deep drilling requires complex, heavy equipment, plus constant
>supervision and troubleshooting by human crews.
>
>Says Farmer, "We'll be lucky if, in the next decade or so, robotic drilling
>on Mars reaches a depth of a couple yards."
>
>So where does that leave us in the search for life on Mars? Farmer says our
>best choice is to pursue the exopaleontology path.
>
>"Finding the signatures of an ancient Martian biosphere means exploring old
>rocks that might preserve traces of life for millions or billions of years,"
>Farmer notes. Among the best places to look on Mars, he says, are deposits
>left by springs and former lakes in the heavily cratered highlands. "The
>rocks there date from a period in Martian history when liquid water was
>common at the surface." In fact, says Farmer, conditions on Mars then were
>likely similar to those on the early Earth at the time when life began.
>
>"Besides water, life also requires energy sources and organic chemical
>building blocks," Farmer explains. "The Mars Exploration Rover Opportunity
>found ample evidence for water in ancient rocks at Meridiani Planum, but the
>rovers' instruments can't detect organic materials." However, NASA's next
>rover, the Mars Science Laboratory, will carry instruments to analyze traces
>of organic substances. It is due for launch in 2009.
>
>Recognizing a Martian fossil may be difficult. "We're not talking about
>stumbling over dinosaur bones," Farmer says.
>
>Instead, the discovery may involve finding biologically formed structures in
>old sedimentary deposits, perhaps like stromatolites found here on Earth.
>Stromatolites are distinctive structures that form in shallow oceans, lakes,
>or streams where microbial colonies trap sediments to form thin repeating
>layers.
>
>Stromatolites also contain microscopic cellular remains and chemical traces
>left by the microbes that formed them. Taken together, such structures
>comprise the primary record of life in ancient rocks on Earth.
>
>For hunting Martian fossils, says Farmer, we will need robotic microscopic
>imagers capable of viewing rocks in many wavelengths as well as seeing
>details as small as a hundredth of a millimeter across. Also needed are
>organic chemistry laboratories to analyze promising rocks. "That will help
>us avoid mistaking non-biological features for biological ones," he says.
>
>Farmer's fieldwork has taken him to extreme microbial habitats in Iceland,
>New Zealand, Yellowstone National Park and Mono Lake, Calif. He has sought
>to understand how modern microbial communities become preserved as fossils.
>Their environments, he notes, span physical and chemical conditions believed
>to be representative of early Mars.
>
>"Studying how microbes become fossils is a key step in developing an
>effective strategy for exopaleontology," Farmer says. "It will help us find
>the best places to explore on Mars and how to look."
>
>IMAGE CAPTION:
>[http://www.asu.edu/news/forthemedia/20070214_Biosignatures.htm]
>The fossilized remains of Calothrix, a common bacterium in Yellowstone
>National Park hot springs, show like branches of a shrub in this microscopic
>image. The "branches" are the bacteria's external sheaths, which have been
>completely entombed in opal, a mineral that frequently crystallizes from
>these hot springs.
>
>Image courtesy of Jack D. Farmer, Arizona State University
>
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>
>
>
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Received on Fri 23 Feb 2007 11:07:44 AM PST