[meteorite-list] Mars Exploration Rovers Images - March 16, 2004

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:51 2004
Message-ID: <200403171609.IAA05694_at_zagami.jpl.nasa.gov>


Drifts of Dust or Something Else?
Press Release Image: Spirit
March 16, 2004

While the interior and far walls of the crater dubbed "Bonneville"
can be seen in the background, the dominant foreground features in
this 180-degree navigation camera mosaic are the wind-deposited drifts
of dust or sand. NASA's Mars Exploration Rover Spirit completed this
mosaic on sol 71, March 15, 2004, from its newest location at the rim
of "Bonneville" crater.

Scientists are interested in these formations in part because they
might give insight into the processes that formed some of the material
within the crater. Thermal emission measurements by the rover indicate
that the dark material just below the far rim of this crater is
spectrally similar to rocks that scientists have analyzed along their
journey to this location. They want to know why this soil-like material
has a spectrum that more closely resembles rocks rather than other
soils examined so far. The drifts seen in the foreground of this mosaic
might have the answer. Scientists hypothesize that these drifts might
consist of wind-deposited particles that are the same as the dark
material found against the back wall of the crater. If so, Spirit may
spend time studying the material and help scientists understand why it
is different from other fine-grained material seen at Gusev.

The drifts appear to be lighter in color than the dark material
deposited on the back wall of the crater. They might be covered by a
thin deposit of martian dust, or perhaps the drift is like other
drifts seen during Spirit's journey and is just a collection of martian

To find out, Spirit will spend some of sol 72 digging its wheels into
the drift to uncover its interior. After backing up a bit, Spirit will
use the panoramic camera and miniature thermal emission spectrometer
to analyze the scuffed area. If the interior material has a similar
spectrum to the dark deposit in the crater, then Spirit will most
likely stay here a little longer to study the drift with the
instruments on its robotic arm. If the material is uniform - that is,
dusty all the way down, Spirit will most likely move off to
another target.

Image credit: NASA/JPL
Browse Image | Medium Image (271 kB) | Large (1.5 MB)



Opportunity Studies Bait in Shark's Cage
Press Release Image: Opportunity
March 16, 2004

In its 49th sol on Mars, NASA's Opportunity had nearly concluded its
scientific examination of the extreme southwestern end of the outcrop
in Meridiani Planum. In the "Shark's Cage" area of the neighborhood
called "Shoemaker's Patio," featured in this image from the front
hazard avoidance camera, Opportunity deployed its arm to study the
features called "Shark's Tooth," "Shark Pellets," and "Lamination."
"Shark's Tooth" is a piece of the unusual red rind that appears to fill
cracks in the outcrop. This rind may be some kind of chemical
alteration of the rocks. "Shark Pellets" is an area of soil that was
under investigation as part of the crater soil survey. "Lamination"
is a target with very thin layers that resemble uniform pages in a book,
an indication of how the sediments were deposited. A final experiment
in this area will be attempted on sol 51. Opportunity's front left
wheel will "scuff" the rock called "Carousel." "Scuffing" involves
scraping the rock with one wheel while holding all the others still.
This experiment essentially turns the rover wheels into tools, to
try and determine the hardness of the target rock.

Image credit: NASA/JPL
Browse Image | Medium Image (137 kB) | Large (1.8 M)
Received on Wed 17 Mar 2004 11:09:20 AM PST

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