[meteorite-list] Mars Called Key To Quest For Alien Life

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:26 2004
Message-ID: <200204121934.MAA17948_at_zagami.jpl.nasa.gov>

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2002/04/08/MN115342.DTL

Mars called key to quest for alien life

Keay Davidson
San Francisco Chronicle
April 8, 2002

Chris McKay's album of family photos opens with a picture of
fossilized bacteria, entombed within rock billions of years old.

"This is one of (my family's) oldest, oldest, oldest ancestors,"
declares the NASA scientist, showing a slide of the photo and
drawing a big laugh from his packed audience. But he's only
half joking.

The quest for "alien" life forms on the primeval Earth and their
possible counterparts on Mars has consumed much of
McKay's career at NASA's Ames Research Center in
Mountain View, he said on the opening day of the space
agency's biannual Astrobiology Science Conference.

If no life is found on Mars, that will suggest that "we are
fundamentally on the wrong track" in our scientific
assumptions about the conditions necessary for the
emergence of life anywhere, said McKay, in a speech
inaugurating the five-day conference. Besides being an
"astrobiologist," he holds the Carl Sagan Chair for the Study of
Life in the Universe at the SETI Institute (SETI stands for
Search for Extraterrestrial Intelligence) in Mountain View.

The Ames conference is scheduled to feature scientists from
around the world discussing their latest findings on topics
such as:

-- Did meteorites ferry bacteria from Mars to Earth?

-- Are there abundant amounts of water on Mars and
elsewhere in space? Scientists believe that water is essential
for the evolution of life as we know it.

-- Can extremely hot geothermal ponds breed new types of
viruses?

-- Might life have evolved in fundamentally different ways on
other planets, e.g. evolving without developing DNA, the genetic code, as
we know it on Earth?

-- Will future space telescopes detect inhabited, Earth-sized
planets that orbit other stars?

The last Astrobiology Science Conference was held in 2000
and attracted 650 attendees "from literally dozens of nations,"
said Ames Director Henry McDonald. "This time around, we
hope to do even better."

McKay's research has taken him to exotic locales such as the
so-called "dry valleys" of Antarctica. There, he studies how
microbes survive in harsh, cold, dry conditions similar to the
surface of Mars.

Despite its present dryness, Mars may have had large
amounts of surface water in its distant past -- perhaps even
an ocean that covered much of its northern hemisphere,
McKay noted. Life forms such as bacteria may have survived
within those waters, and their fossils may be uncovered by
future astronauts.

He displayed a photo of what appears to be a 60-mile-wide
crater on Mars, into which a river drained. Conceivably, that
crater might once have supported "a huge lake," he said.

Several years ago, scientists from NASA and other
institutions reported finding objects that resembled fossilized
microbes within a Mars meteorite, recovered in Antarctica.
Scientists still debate whether the so-called fossils are true
fossils. McKay noted that they contained tiny metallic grains
similar to those deployed by terrestrial bacteria for the
purposes of navigation.

That's a hint, he said, that if Martian bacteria ever existed,
then they "independently discovered a way to use magnets to
navigate."
Received on Fri 12 Apr 2002 03:34:54 PM PDT