[meteorite-list] Carbon Find Fuels Hope for Life on Mars (Nakhla Meteorite)
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Feb 10 12:32:49 2006
Carbon find fuels hope of there being life on Mars
The Scotsman (United Kingdom)
February 10, 2006
THE best evidence yet of life on Mars has been discovered in a meteorite
that landed on Earth nearly 100 years ago.
Scientists at NASA in the United States and the UK's Open University
found traces of carbon in tiny tubes inside the rock that resemble
material found in fractures etched by microbes in volcanic glass from
the Earth's ocean floor.
Even if the carbon was not the product of Martian microbes, its
discovery, if confirmed, means that the two basic building blocks for
life - carbon and water - are, or were, present on the planet. Carbon
has been found in meteorites originating from Mars before, but sceptics
have dismissed these, as it could not be proven that the Martian
material was not contaminated with carbon from Earth.
However, this meteorite, which landed in the Egyptian town of Nakhla in
1911, killing a dog, was almost completely encased in a crust of
material, which it is thought will have prevented earthly contaminants
from getting in.
Professor Colin Pillinger, of the Open University, told The Scotsman:
"These are very interesting results. We are very confident this stuff is
carbon, and that is interesting because no carbon has ever been found on
Mars, apart from in the atmosphere.
"For life to exist, you obviously have to have carbon fixed into organic
matter. We cannot say we've found living matter, but we have found
organic matter in meteorites. This is the best evidence we have yet of
indigenous [Martian] carbon."
He said further tests had to be carried out to show that the carbon was
Martian. The meteorite is known to come from Mars because tiny air
bubbles inside the rock have been matched to the planet's atmosphere,
which was measured by a probe.
Prof Pillinger, the scientist behind the failed Beagle 2 mission to
Mars, said the meteorite was a "totally unique sample", adding that its
thick crust "would have kept contamination out".
Dr Kathie Thomas-Keprta, of NASA's Johnson Space Centre, who co-authored
a paper on the meteor to be presented at the Lunar and Planetary Science
Conference in Houston, Texas, next month, said: "Our results strongly
support an interpretation that this carbon is indigenous to Mars and is
very unlikely to be a terrestrial contaminant."
However, Dr Caroline Smith, meteorite curator at London's Natural
History Museum, where the Nakhla rock was kept, said more work was
needed before any conclusions could be made.
Received on Fri 10 Feb 2006 12:29:48 PM PST