NASA Spacecraft Provides Travel Tips For Mars Rover
SAN FRANCISCO -- NASA's Mars Opportunity rover is getting important tips from an orbiting spacecraft as it explores areas that might hold clues about past Martian environments.Researchers are using a mineral-mapping instrument aboard NASA's Mars Reconnaissance Orbiter (MRO) to help the rover investigate a large ancient crater called Endeavour. MRO's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is providing maps of minerals at Endeavour's rim that are helping the team choose which area to explore first and where to go from there.
As MRO orbits more than 150 miles high, the CRISM instrument provides
mapping information for mineral exposures on the surface as small as
a tennis court.
"This is the first time mineral detections from orbit are being used
in tactical decisions about where to drive on Mars," said Ray
Arvidson of Washington University in St. Louis. Arvidson is the
deputy principal investigator for the Spirit and Opportunity rovers
and a co-investigator for CRISM.
Opportunity's science team chose to begin driving the rover toward the
14-mile-wide crater in 2008, after four years studying other sites in
what initially was planned as a three-month mission. The rover has
traveled approximately nine miles since setting out for Endeavour
crater. It will take several months to reach it.
The team plans for Opportunity's exploration of Endeavour to begin at
a rim fragment called Cape York. That feature is too low to be
visible by the rover, but appears from orbit to be nearly surrounded
by water-bearing minerals. The planned route then turns southward
toward a higher rim fragment called Cape Tribulation, where CRISM has
detected a class of clay minerals not investigated yet by a ground
mission.
Spacecraft orbiting Mars found these minerals to be widespread on the
planet. The presence of clay minerals at Endeavour suggests an
earlier and milder wet environment than the very acidic wet one
indicated by previous evidence found by Opportunity.
"We used to have a disconnect between the scale of identifying
minerals from orbit and what missions on the surface could examine,"
said CRISM team member Janice Bishop of NASA's Ames Research Center
in Moffett Field, Calif., and the SETI Institute of Mountain View,
Calif. Now, rovers are driving farther and orbital footprints are getting smaller."
Ten years ago, an imaging spectrometer on the Mars Global Surveyor
orbiter found an Oklahoma-sized are with a type of the mineral
hematite exposed. This discovery motivated selection of the area as
Opportunity's 2004 landing site. Each pixel footprint for that
spectrometer was two miles across. CRISM resolves areas about 60 feet
across. Last fall, the instrument began using a pixel-overlap
technique that provided even better resolution.
Opportunity has just reached a 90-meter-diameter (300-foot-diameter)
crater called Santa Maria where CRISM detected a patch of ground with
indications of water bound into the mineral. Opportunity will conduct
a science campaign at the crater for the next several weeks to
compare the ground results to the orbital indications.
A Martian year lasts approximately 23 months. During the past Martian
year, Opportunity covered more than 7.5 miles of the mission's 16
total miles traveled since it landed in January 2004. The rover has
returned more than 141,000 images.
MRO reached the Red Planet in 2006 to begin a two-year primary science
mission. Its data show Mars had diverse wet environments at many
locations for differing durations during the planet's history, and
climate-change cycles persist into the present era. The mission has
returned more planetary data than all other Mars missions combined.
JPL manages the Mars Exploration Rovers and the Mars Reconnaissance
Orbiter for NASA's Science Mission Directorate in Washington. The
Johns Hopkins University Applied Physics Laboratory in Laurel, Md.,
manages CRISM.
For more information about Mars missions, visit:
http://www.nasa.gov/mars
Source: NASA
