[meteorite-list] More Pieces of Mars Found

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:54:00 2004
Message-ID: <200202041651.IAA14141_at_zagami.jpl.nasa.gov>

http://dsc.discovery.com/news/briefs/20020128/meteorite.html

More Pieces of Mars Found
By Larry O'Hanlon
Discovery News
January 28, 2002

Jan. 28 - Five more chunks of the planet Mars have turned up on Earth,
report meteorite scientists who plan on presenting their discoveries at a
scientific meeting in March.

In all, the new meteorites bring the count to 24 fragments of the Red Planet
have been found on Earth after being blasted off the Red Planet by impacts
of asteroids or comets. Reports on the new interplanetary fragments will be
presented at the Lunar and Planetary Science Conference in Texas.

"There is an unusual number of Antarctic Mars meteorites being reported,"
remarks Ron Baalke of NASA's Jet Propulsion Laboratory, who keeps count of
Martian meteorites.

The reason? "People are out there hunting like crazy," said Marilyn
Lindstrom, who served for years as the meteorite curator at NASA's Johnson
Space Flight Center.

The bulk of the new discoveries are by Japanese and Chinese scientists. The
Japanese meteorite hunters were particularly overdue for a Martian
meteorite, she said, because they have been hunting for years and found
about 4,000 meteorites of other types.

Just a fraction of one percent of all meteorites is Martian, Lindstrom said.
The majority of meteorites are pieces of asteroids and other debris that
never was part of a planetary body. About eight percent of meteorites are
bits of the moon, shot to Earth by the same impacts that created the moon's
pocked surface.

Although the newest members of the Martian meteorite family are mostly from
Antarctica, there is also one Saharan meteorite. Sandy deserts and
Antarctica are good places for finding meteorites because the space rocks
stand out from the bare surroundings.

All of the new meteorites are thought to be from Mars because of their
telltale peculiar iron-manganese and oxygen isotope compositions. These
chemical signs tie the rocks to the first discovered Martian meteorites that
contain small bubbles of Martian atmosphere - the surest sign that a
meteorite is from Mars.

Because meteorites are the only actual samples scientists have from the
fourth planet, they are considered invaluable.

"Basically a lot of the understanding of how Mars evolved comes from the
rocks," Lindstrom said. "We're having a look into the Martian crust."

Plans are already underway by the European Space Agency for a mission to
Mars that will bring back samples to Earth for study. Until then, however,
the meteorites and images from spacecraft are the only clues to Mars'
history.
Received on Mon 04 Feb 2002 11:51:14 AM PST