[meteorite-list] NASA's Mars Rovers Continue to Explore & Amaze

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Dec 5 11:47:01 2005
Message-ID: <200512051645.jB5GjCZ18788_at_zagami.jpl.nasa.gov>

December 5, 2005

George Deutsch/Erica Hupp
Headquarters, Washington
(202) 358-1324/1237

Guy Webster
Jet Propulsion Laboratory, Pasadena, Calif.
(818) 354-6278

RELEASE: 05-420

NASA'S MARS ROVERS CONTINUE TO EXPLORE & AMAZE

NASA's durable twin Mars rovers have successfully explored the surface
of the mysterious red planet for a full Martian year (687 Earth
days). Opportunity starts its second Martian year Dec. 11; Spirit
started a new year three weeks ago. The rovers' original mission was
scheduled for only three months.

"The rovers went through all of the Martian seasons and are back to
late summer," said Dr. John Callas of NASA's Jet Propulsion
Laboratory, Pasadena, Calif. He is deputy rover project manager.
"We're preparing for the challenge of surviving another Martian
winter."

Both rovers keep finding new variations of bedrock in areas they are
exploring on opposite sides of Mars. The geological information they
have collected increased evidence about ancient Martian environments
including periods of wet, possibly habitable conditions.

Spirit is descending from the top of "Husband Hill" to examine a
platform-like structure seen from the summit. It will then hurry
south to another hill in time to position itself for maximum
solar-cell output during the winter.

"Our speed of travel is driven as much by survival as by discovery,
though the geology of Husband Hill continues to fascinate, surprise,
puzzle and delight us," said Dr. Steve Squyres of Cornell University,
Ithaca, N.Y., principal investigator for the rover's science
instruments. "We've got this dramatic topography covered with sand
and loose boulders, then, every so often, a little window into the
bedrock underneath."

>From the composition and texture of more than six different types of
rock inspected, scientists deduced what this part of Mars was like
long ago. "It was a hot, violent place with volcanic explosions and
impacts," Squyres said. "Water was around, perhaps localized hot
springs in some cases and trace amounts of water in other cases.

Aided by a good power supply from Spirit's solar cells, researchers
have been using the rover at night for astronomical observations. One
experiment watched the sky during a meteor shower as Mars passed
through the debris trail left by a passage of Halley's comet. "We're
taking advantage of a unique opportunity to do some bonus science we
never anticipated we would be able to do," Said Cornell's Dr. Jim
Bell, lead scientist for the rovers' panoramic cameras.

Opportunity is examining bedrock exposures along a route between
Endurance and Victoria craters. It recently reached what appears to
be a younger layer of bedrock than examined inside Endurance. In
Endurance, the lowest layers of bedrock were deposited as windblown
dunes. Some of the upper layers were deposited as underwater
sediments, indicating a change from drier to wetter conditions over
time.

The bedrock Opportunity began seeing about two-thirds of the way to
Victoria appears to lie higher than the upper layers at Endurance,
but its texture is more like the lowest layer, petrified sand dunes.
This suggests the change from drier to wetter environmental
conditions may have been cyclical.

Iron-rich granules are abundant in all the layers at Endurance but are
much smaller in the younger bedrock. These granules were formed by
effects of water soaking the rocks. One possibility for why they are
smaller is these layers spent less time wet. Another is the material
in these layers had a different chemistry to begin with.

Rover researchers are presenting their latest data today during the
American Geophysical Union meeting in San Francisco. Images and
information about the rovers and their discoveries are available on
the Web at:

http://www.nasa.gov/vision/universe/solarsystem/mer_main.html

For more information about NASA and agency programs on the Web, visit:


http://www.nasa.gov/home


-end-
Received on Mon 05 Dec 2005 11:45:12 AM PST