Smooth inclusions in Wishstone rock.

From: Robert Clark (rgregoryclark_at_yahoo.com)
Date: 12/31/04 

Date: 31 Dec 2004 07:35:06 -0800

A Rock Like None Before, Brushed.
"Scientists viewed a rock like none seen before on Mars when NASA's
Mars Exploration Rover Spirit brushed the surface and took magnified
images of this rock dubbed "Wishstone." The circular area of interest,
measuring approximately 5 centimeters (2 inches) in diameter, revealed
darker pieces of material randomly distributed within a lighter-colored
matrix. The rock has poorly sorted granular material, with grain sizes
ranging from fine to coarse and some grains that are very angular in
shape. Spirit used its microscopic imager on martian day, or sol, 333
(Dec. 9, 2004) to take the four individual frames that are combined
into this mosaic view."
http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20041230a.html

Curious are the dark, smooth inclusions apparent in the rock. These
might be similar to the smooth, glassy inclusions seen by Spirit in
Humphrey and Mazatzal rocks.
Alternatively, they could be examples of, apparent, sedimentary films
seen at the Opportunity site:

From: rgregorycl...@yahoo.com (Robert Clark)
Newsgroups:
sci.astro,alt.sci.planetary,sci.geo.geology,sci.geo.mineralogy,sci.bio.misc

Subject: Sedimentary films at Opportunity site.
Date: 18 Mar 2004 16:26:04 -0800
http://groups-beta.google.com/group/sci.astro/msg/11a829ece45426b7

Clays perhaps?

Bob Clark

baalke@earthlink.net wrote:
> http://marsrovers.jpl.nasa.gov/mission/status.html
>
> SPIRIT UPDATE: Spirit Eats a Potato-Sized Rock - sol 333-345,
> December 23, 2004
>
> Spirit finished work at a rock called "Wishstone," then continued to
> make slow progress up "Husband Hill." Wishstone is different than any
> rock Spirit previously studied either on the plains or in the hills.
> Scientists and engineers used the miniature thermal emission
> spectrometer to find similar rocks for further study.
>
> A potato-sized rock got caught in Spirits's right rear wheel on sol
> 339,
> causing the wheel to stall and ending the drive for that sol. Small
> moves of the wheel on subsequent sols dislodged the rock, but the
rock
> remains close to the wheel, so the team is planning small, careful
> steps
> to move the wheel away from the rock so it will not become jammed
> again.
> Spirit remains in excellent health.
>
> Sol-by-sol Summaries:
>
> Atmospheric observations using the miniature thermal emission
> spectrometer, navigation camera, and panoramic camera continue on a
> daily basis.
>
> On sol 333, Spirit used the brush of the rock abrasion tool brush to
> scrub a small section of Wishstone and took microscopic images of the
> spot. Spirit then placed the alpha particle X-ray spectrometer on the
> spot for collecting data overnight.
>
> On sol 334, Spirit removed the alpha particle X-ray spectrometer and
> then used the rock abrasion tool to drill into Wishstone. After
taking
> more microscopic images, Spirit placed the alpha particle X-ray
> spectrometer on the hole for an overnight observation.
>
> On sol 335, Spirit removed the alpha particle X-ray spectrometer from
> the hole and replaced it with the Mossbauer spectrometer. Spirit also
> started a long series of Mossbauer observations that would last until
> the early morning of sol 337.
>
> On sol 337, Spirit stowed its robotic arm, then bumped backwards to
> take
> final images of Wishstone and the rock abrasion tool hole. Spirit was
> commanded to drive 15 meters (49 feet), but drove only about 6 meters
> (20 feet) due to experiencing slippage of up to 80 percent on uphill
> portions of the drive.
>
> On sol 338, Spirit drove 8 meters (26 feet) with 25 meters (82 feet)
of
> commanded motion. Spirit saw up to 95-percent slip on some of the
drive
> segments due to sandy terrain and the rover's tilt of 15 to 20
degrees.
>
> On sol 339, the rover team attempted another 25-meter (82-foot)
drive.
> This was cut short at the start when the right rear wheel ingested a
> potato-sized rock. The rock apparently jammed between the inner part
of
> the wheel and the drive mechanism, causing the drive current to
exceed
> a
> pre-set limit, resulting in a safe motor stall.
>
> Sol 340 - Spirit made observations with the miniature thermal
emission
> spectrometer to seek other rock targets similar to Wishstone. Turning
> the right rear wheel about 60 degrees successfully un-jammed the
rock,
> but it remained inside the wheel.
>
> Sols 341, 342 and 343 were planned as a combined three-sol plan that
> included observations with the miniature thermal emission
spectrometer
> each sol. On sol 341, Spirit used its microscopic imager and its
> Mossbauer spectrometer to examine disturbed soil in front of the
rover.
> It switched to the alpha particle X-ray spectrometer overnight to
> gather
> more compositional information about the same target. On sol 342,
> Spirit
> performed a mid-day tool change back to the Mossbauer spectrometer.
On
> sol 343, the rover stowed the robotic arm and took images with the
> panoramic camera of targets that had been observed with the miniature
> thermal emission spectrometer. Spirit then performed a small maneuver
> but did not significantly change the position of the rock in the
wheel.
>
> Sol 344 - Spirit performed more remote sensing and did a maneuver
that
> lifted the right rear wheel slightly out of a hole, but the rock
> remains
> partially in the wheel. The wheel is about one-third buried in the
soft
> soil, making it difficult for the rock to escape until the wheel gets
> out of the hole.
>
> Sol 345 - Spirit successfully executed another small maneuver to get
> the
> right rear wheel out of hole and get the rock out of the wheel, but
> more
> steps will be required. The rover also used the panoramic camera and
> miniature thermal emission spectrometer to acquire information about
> nearby targets. Sol 345 ended on Dec. 22.

Relevant Pages

  • Mars Exploration Rover Update - December 23, 2004
    ... Spirit finished work at a rock called "Wishstone," then continued to ... A potato-sized rock got caught in Spirits's right rear wheel on sol ...
    (sci.astro)
  • Re: Smooth inclusions in Wishstone rock.
    ... Spirit View of 'Wishstone' ... Clay is known to be highly absorptive of phosphorus because of its ... the target rock than is usually done. ... >> causing the wheel to stall and ending the drive for that sol. ...
    (sci.astro)
  • Mars Exploration Rover Update - June 11, 2007
    ... SPIRIT UPDATE: Spirit Studies Layered Rocks at 'Home Plate' - ... target known as "Gertrude Weise," Spirit drove to a perch on the ... panoramic camera, surveys of the sky and ground using the miniature ... and continued analysis of a rock target known as "Pesapallo," ...
    (sci.space.news)
  • Re: Mars Exploration Rover Update - December 5, 2006
    ... SPIRIT UPDATE: Spirit Slowly Begins Driving Again - sol 1024-1038, ... The rock, according to principal investigator ... the sky and ground using the miniature thermal emission spectrometer, ...
    (sci.space.policy)
  • Mars Exploration Rover Update - August 23, 2004
    ... Spirit continued work over the past nine sols at a rock called "Clovis." ... The rover used its rock abrasion tool, microscopic imager, alpha ... On sol 210, Spirit drove up steep terrain to reach the exact spot on ...
    (sci.astro)