Mars Odyssey THEMIS Images - April 5-9, 2004

MARS ODYSSEY THEMIS IMAGES
April 5-9, 2004

o Flows from Olympus Mons (Released 5 April 2004)
http://themis.la.asu.edu/zoom-20040405a.html

o Olympus Mons Lava Flows (Released 6 April 2004
http://themis.la.asu.edu/zoom-20040406.html

o Arsia Mons Flows in Infrared (Released 7 April 2004)
http://themis.la.asu.edu/zoom-20040407a.html

o Infrared of Meroe Patera Flows (Released 8 April 2004)
http://themis.la.asu.edu/zoom-20040408a.html

o Young and Old Flows (Released 9 April 2004)
http://themis.la.asu.edu/zoom-20040409a.html


All of the THEMIS images are archived he

http://themis.la.asu.edu/latest.html

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission
for NASA's Office of Space Science, Washington, D.C. The Thermal Emission
Imaging System (THEMIS) was developed by Arizona State University,
Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing.
The THEMIS investigation is led by Dr. Philip Christensen at Arizona State
University. Lockheed Martin Astronautics, Denver, is the prime contractor
for the Odyssey project, and developed and built the orbiter. Mission
operations are conducted jointly from Lockheed Martin and from JPL, a
division of the California Institute of Technology in Pasadena.

Opportunity took this MI photo of the soil outside Eagle Crater a few days
ago:

http://tinyurl.com/26clx

Don't many of those small pebbles (about 1m in size) look like they fit
together? If so, what process would cause that?

Here's a closeup of a good example: http://www.copperas.com/astro/pieces.jpg

Image info:

Image info for: 1M134664662EFF1000P2936M2M1
Spacecraft: OPPORTUNITY
Camera: Microscopic Imager, dust cover OPEN
Spacecraft clock: 134664662 (seconds since January 1, 2000, 11:58:55.816
UTC)
Product type: EDR full frame
Site number: 10
Drive number: 00
Command sequence number: P2936 (PMA or remote sensing instrument) MI
Producer: MIPL/JPL
Acquisition time (Earth): Wed Apr 7 22:38:55 EDT 2004
Acquisition time (Mars): Sol 73 11:42:26

Joe

Joe Knapp wrote:

Opportunity took this MI photo of the soil outside Eagle Crater a few days
ago:

http://tinyurl.com/26clx

Don't many of those small pebbles (about 1m in size) look like they fit
together? If so, what process would cause that?

Crystallization.

Here's a closeup of a good example: http://www.copperas.com/astro/pieces.jpg

"Father Haskell" wrote
Joe Knapp wrote:

Opportunity took this MI photo of the soil outside Eagle Crater a few
days
ago:

http://tinyurl.com/26clx

Don't many of those small pebbles (about 1m in size) look like they fit
together? If so, what process would cause that?

Crystallization.

Of salt?

Would that require water?

Interesting too that if these are crystals formed in place that they are
exposed relatively dust-free on the surface (rather than weathered-out as
with the spherules).

Found a reference to:

"Compaction: The weight of overlying sediment squeezes water and air out of
the sediment, and grains rearrange to fit tightly."

Could that possibly be it?

Joe

"Joe Knapp" wrote in message
. com...
Opportunity took this MI photo of the soil outside Eagle Crater a few days
ago:

http://tinyurl.com/26clx

Don't many of those small pebbles (about 1m in size) look like they fit
together? If so, what process would cause that?

Here's a closeup of a good example:
http://www.copperas.com/astro/pieces.jpg

Gravel tends to look that way....

all the fines have been blown away.

I've seen that in the SW and Antarctica

bob

"Joe Knapp" wrote in message
. com...
Opportunity took this MI photo of the soil outside Eagle Crater a few days
ago:

http://tinyurl.com/26clx

Don't many of those small pebbles (about 1m in size) look like they fit
together? If so, what process would cause that?

Here's a closeup of a good example: http://www.copperas.com/astro/pieces.jpg




The bounce rock photos hint at the answer.

In this image the smaller spheres seem to be more numerous near bounce rock.
http://mars.gh.wh.uni-dortmund.de/me...5L5L6.jpg.html

In this image of bounce rock, the spray to the right appears quite like the grains of
the
dune below
http://mars.gh.wh.uni-dortmund.de/me...5L5L6.jpg.html

In this image of a ripple, the grains appear similar to the spray given off by bounce
rock
http://mars.gh.wh.uni-dortmund.de/me...5L6L6.jpg.html



It seems pretty clear that the encrusted outcrops are the source of both the
spheres, small and large, and the grains for the cemented dunes. I would
suspect the large endurance crater nearby is the source of the bulk of
them all.


This close-up of bounce rock...well..it's not a rock is it?
http://marsrovers.jpl.nasa.gov/galle...YP2956M2M1.JPG


I still feel that the smaller grains are the result of bacteria, and the spheres
the result of multi celled reef life.


The microscopic pictures should be of interest.

"Results and Discussion: Our FE-SEM analysis
indicates a range of microbial life forms on the fractured
stromatolite surfaces. Spheroidal features are the
most common, with four distinct populations, characterized
by their highly uniform intrapopulation sizes:"

Lunar and Planetary Science XXXII (2001)
http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1068.pdf


Jonathan

s







Image info:

Image info for: 1M134664662EFF1000P2936M2M1
Spacecraft: OPPORTUNITY
Camera: Microscopic Imager, dust cover OPEN
Spacecraft clock: 134664662 (seconds since January 1, 2000, 11:58:55.816
UTC)
Product type: EDR full frame
Site number: 10
Drive number: 00
Command sequence number: P2936 (PMA or remote sensing instrument) MI
Producer: MIPL/JPL
Acquisition time (Earth): Wed Apr 7 22:38:55 EDT 2004
Acquisition time (Mars): Sol 73 11:42:26

Joe