[meteorite-list] NASA Mars Rover's First Soil Analysis Yields Surprises

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:04 2004
Message-ID: <200401210122.RAA21330_at_zagami.jpl.nasa.gov>

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Guy Webster (818) 354-5011
Jet Propulsion Laboratory, Pasadena, Calif.

Donald Savage (202) 358-1547
NASA Headquarters, Washington, D.C.

NEWS RELEASE: 2004-025 January 20, 2004

NASA Mars Rover's First Soil Analysis Yields Surprises

The first use of the tools on the arm of NASA's Mars Exploration Rover
Spirit reveals puzzles about the soil it examined and raises
anticipation about what the tool will find during its studies of a
martian rock.

Today and overnight tonight, Spirit is using its microscope and two
up-close spectrometers on a football-sized rock called Adirondack,
said Jennifer Trosper, mission manager at NASA's Jet Propulsion
Laboratory, Pasadena, Calif.

"We're really happy with the way the spacecraft continues to work for
us," Trosper said. The large amount of data -- nearly 100 megabits --
transmitted from Spirit in a single relay session through NASA's Mars
Odyssey spacecraft today "is like getting an upgrade to our Internet
connection."

Scientists today reported initial impressions from using Spirit's
alpha particle X-ray spectrometer, Moessbauer spectrometer and
microscopic imager on a patch of soil that was directly in front of
the rover after Spirit drove off its lander Jan. 15.

"We're starting to put together a picture of what the soil at this
particular place in Gusev Crater is like. There are some puzzles and
there are surprises," said Dr. Steve Squyres of Cornell University,
Ithaca, N.Y., principal investigator for the suite of instruments on
Spirit and on Spirit's twin, Opportunity.

One unexpected finding was the Moessbauer spectrometer's detection of
a mineral called olivine, which does not survive weathering well. This
spectrometer identifies different types of iron-containing minerals;
scientists believe many of the minerals on Mars contain iron. "This
soil contains a mixture of minerals, and each mineral has its own
distinctive Moessbauer pattern, like a fingerprint," said Dr. Goestar
Klingelhoefer of Johannes Gutenberg University, Mainz, Germany, lead
scientist for this instrument.

The lack of weathering suggested by the presence of olivine might be
evidence that the soil particles are finely ground volcanic material,
Squyres said. Another possible explanation is that the soil layer
where the measurements were taken is extremely thin, and the olivine
is actually in a rock under the soil.

Scientists were also surprised by how little the soil was disturbed
when Spirit's robotic arm pressed the Moessbauer spectrometer's
contact plate directly onto the patch being examined. Microscopic
images from before and after that pressing showed almost no change. "I
thought it would scrunch down the soil particles," Squyres said.
"Nothing collapsed. What is holding these grains together?"

Information from another instrument on the arm, an alpha particle
X-ray spectrometer, may point to an answer. This instrument "measures
X-ray radiation emitted by Mars samples, and from this data we can
derive the elemental composition of martian soils and rocks," said Dr.
Johannes Brueckner, rover science team member from the Max Planck
Institute for Chemistry, Mainz, Germany. The instrument found the most
prevalent elements in the soil patch were silicon and iron. It also
found significant levels of chlorine and sulfur, characteristic of
soils at previous martian landing sites but unlike soil composition on
Earth.

Squyres said, "There may be sulfates and chlorides binding the little
particles together." Those types of salts could be left behind by
evaporating water, or could come from volcanic eruptions, he said. The
soil may not have even originated anywhere near Spirit's landing site,
because Mars has dust storms that redistribute fine particles around
the planet. The next target for use of the rover's full set of
instruments is a rock, which is more likely to have originated nearby.

Spirit landed in the Connecticut-sized Gusev Crater on Jan. 3 (EST and
PST; Jan. 4 Universal Time). In coming weeks and months, according to
plans, it will examine rocks and soil for clues about whether the past
environment there was ever watery and possibly suitable to sustaining
life. Spirit's twin Mars Exploration Rover, Opportunity, will reach
Mars on Jan. 25 (EST and Universal Time; 9:05 p.m., Jan. 24, PST) to
begin a similar examination of a site on the opposite side of the
planet.

JPL, a division of the California Institute of Technology in Pasadena,
manages the Mars Exploration Rover project for NASA's Office of Space
Science, Washington, D.C. Images and additional information about the
project are available from JPL at

http://marsrovers.jpl.nasa.gov

and from Cornell University, Ithaca, N.Y., at

http://athena.cornell.edu/ .

-end-
Received on Tue 20 Jan 2004 08:22:52 PM PST