[meteorite-list] NASA Rover Finds Meteorite on Surface of Mars

From: Charles Viau <cviau_at_meteoritecentral.com>
Date: Tue Jan 18 19:05:11 2005
Message-ID: <20050119000509.DEB2C26551_at_ns4.beld.net>

There must be thousands, if not millions of them just sitting on the
surface. Just imagine the odds. This rover, for all the distance it has
traveled, barely measures a walk in the park, and it comes across a
basketball size iron meteorite? WOWZER.

CharlyV

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Subject: [meteorite-list] NASA Rover Finds Meteorite on Surface of Mars



http://www.montereyherald.com/mld/montereyherald/news/politics/10674958.htm

NASA rover finds meteorite on surface of Mars
JOHN ANTCZAK
Associated Press
January 18, 2005

LOS ANGELES - In a stroke of luck, the NASA rover Opportunity has
discovered a basketball-size metal meteorite sitting on the surface of
Mars, the mission's main scientist said Tuesday.

Opportunity came upon the meteorite last week while it was taking a look
at a spacecraft shell that was jettisoned before landing after
protecting the rover during its plunge through the martian atmosphere.

Tests performed during the weekend confirm it is a nickel-iron
meteorite, said Steve Squyres, a Cornell University scientist who is the
principal investigator for NASA's Mars Exploration Rovers mission.

"I didn't see this one coming," Squyres said. "I try very hard to
anticipate the things that we might find and the things we might need to
know, and be prepared for things, but an iron meteorite was not
something that I was expecting."

Whether or not other meteorites are found may help scientists determine
whether the martian surface is being covered by wind-blown materials or
whether surface material is being stripped away, Squyres said.

Opportunity landed Jan. 24 on the Meridiani plains, halfway around the
planet from where its twin, Spirit, set down in the Gusev Crater region
on Jan. 3, 2004.

Opportunity, a six-wheeled robot geologist, quickly discovered rocks
showing that its area of Meridiani was once soaked in water, the major
scientific finding of the twin-rover mission. After that it explored
rocks in a deep crater and then went to conduct an engineering study of
its jettisoned heat shield. The meteorite was sitting nearby.

"I've actually told the team that we probably shouldn't linger here long
because this is obviously the place at Meridiani Planum where large
metal objects fall from the sky," Squyres joked.

The meteorite immediately appeared different from anything scientists
had seen at either landing site.

"And then we looked at it with our infrared spectrometer and it looked
like the martian sky, which is really weird," he said. The metal
surface, he explained, was reflecting sky radiation instead of emitting
much of its own.

During the weekend, the rover drove to the meteorite and deployed its
instrument arm to confirm its origin.

The rover used its brush to remove dust but did not try to grind into
the meteorite with its rock abrasion tool because of the outcome of a
test conducted by the tool's maker, Honeybee Robotics of Manhattan.

"We contacted the meteorite department at the American Museum of Natural
History in New York and they were generous enough to give us a piece of
nickel-iron meteorite to try grinding into, and in like an hour of
grinding we wore away about 25 percent of the grinding heads," Squyres said.

"We designed our rock abrasion tool for rock. We didn't design it for
nickel-iron alloys."

Scientists are not interested in the meteorite itself. Rather, they want
to see if other objects spotted out on the Meridiani plains are also
meteorites and what that might tell them about Mars.

"You've got sort of a steady rain of meteorites on to the martian
surface. It's at a very slow rate, but they are going to accumulate over
time." Squyres said.

If sand is continually blowing in and being deposited on the surface,
burying things and building up terrain over time, meteorites will be
covered and few will be seen, he said. But if fine surface material is
being continuously stripped away by the wind, coarse things like
meteorites will be left behind and their accumulation will show.

"So whether you're seeing a net accumulation or a net burial of the
meteorites is going to tell you something about what the erosion or
deposition rates are out on the plains," he said.

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Received on Tue 18 Jan 2005 07:05:11 PM PST