[meteorite-list] Images From Mars Rover Reveal Mysterious Lumps - Scientists Baffled By Sandpaper-Like Patches on Surface

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:03 2004
Message-ID: <200401180133.RAA05354_at_zagami.jpl.nasa.gov>

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/01/17/MARS.TMP

Images from Mars rover reveal mysterious clumps

Scientists baffled by sandpaper-like patches on surface

David Perlman
San Francisco Chronicle
January 17, 2004

Pasadena -- Ecstatic scientists used the Mars rover's powerful camera Friday
to take the first close-up images ever made of the Martian surface and
immediately confronted a new mystery over what they saw.

The images that Spirit sent down from its Martian parking spot, a few feet
in front of its landing pad, was a flat patch of fine- and coarse-grained
sand -- much of it stuck together in clumpy patches that scientists conceded
they did not yet understand.

The pictures, taken in stereoscopic clarity by Spirit's Microscopic Imager,
appeared for all the world like a patch of coarse-grained sandpaper seen by
any layman through a modest magnifying glass.

But to Kenneth Herkenhoff, an astrogeologist with the U. S. Geological
Survey and a member of Spirit's science team, the images might show some
kind of electrostatic force operating on the fine-grained materials, or they
could possibly indicate that the roughened clumps of sand were formed
billions of years ago by salts that bound the grains together when the
chemicals were wet.

Countless other theories are being proposed by the mysterious cohesiveness
of the sandy stuff, said Rob Sullivan of Cornell, another member of the
science team. In coming days, Sullivan and his colleagues plan to spin each
of the rover's six driving wheels separately in order to dig trenches in the
sand, and then focus the Microscopic Imager on the soil a few inches beneath
the surface.

Steve Squyres, the lead scientist on the Spirit team, took one look at the
images his colleagues are already puzzling over and exclaimed with his usual
unrestrained excitement, "Hey, how about that Microscopic Imager! And just
wait a sol or two -- you ain't seen nothing yet."

Although it was morning at NASA's Jet Propulsion Laboratory in Pasadena, it
was long after dark on Mars, where each Martian day is called a sol, and
Spirit was asleep. But earlier -- shortly after midnight in California --
the sun was shining on Gusev Crater, the dust from last December's windstorm
half-way across the planet was diminishing, and Mark Adler, Spirit's mission
manager for the day was calling it "Lucky Sol 13" -- the 13th Martian day
since Spirit landed on the planet Jan. 3.

Everything on the spacecraft was working superbly, Adler said, and Eric
Baumgartner, the engineer responsible for the functioning of Spirit's
movable robotic arm, which carries the spacecraft's major tools, reported
his team had tested the arm through every possible position throughout the
night. The articulated arm passed every test.

That arm, mounted on the front of the rover, can carry the Microscopic
Imager to within a fraction an inch of any object before its dust swivels
away and the lens almost grazes its target. About the size of a human arm,
the robotic device has a shoulder, an elbow and a wrist that can swivel in
any direction, to hold the spacecraft's two spectrometers and the RAT -- the
Rock Abrasion Tool -- that will be used to grind into the surfaces of rocks
and expose whatever lies inside.

Mission Manager Adler told reporters that although Spirit would remain
parked in its present spot for the next day or two -- "a couple of sols or
so," as he put it -- the impatient scientists are eager for it to start
traveling as long as it can rove to new and intriguing targets in complete
safety.

As of today it is only seven days until Spirit's twin rover, named
Opportunity, reaches Mars and makes its dangerous effort to land on its
target area, a flat plain called Meridiani Planum halfway around the planet
from Gusev Crater. Rockier than the region Spirit is exploring, its center
is a site called Hematite, so named because observations from orbit by the
Mars Odyssey and Mars Global Surveyor spacecraft indicate that the gray iron
oxide mineral that is often formed in water may be abundant there.

Joy Crisp, the Jet Propulsion Laboratory project scientist, said the last
days of Opportunity's flight trajectory appeared safely on course and that
probably only one more course correction maneuver -- the fourth since
Opportunity began its venture into space last July 7 -- would be needed
before it lands on its target.
Received on Sat 17 Jan 2004 08:33:45 PM PST