Spirit Grinds Adirondack, Looks for Iron

Quantum Jim writes "Space.com reported on Friday that Spirit used its Rock Abrasion Tool against a Martian rock dubbed Adirondack. Although the rover spent three hours grinding the rock, it was only skinned by about 2.7 mm. Scientists say this is due to an unexpected amount of resistance. Spirit is currently standing by for ground contollers to deactivate a safety feature so it can be repositioned"

Comments

eh...

[deglr6328]

While Spirit's drilling of an igneous rock is kindof interesting, it's (IMHO) comparatively dull when contrasted with Opportunity's microscopic images of the sedimentary rock at the Meridiani location. The layers could have been formed by sedimentation at the bottom of a lake or by volcanic ash being succesively deposited by eruptions, we should know within a day or two when the APXS and Moessbauer spectrometer reveal the chemical makeup of the rocks.

Re:eh...

[Anonymous Coward]

It's not quite that simple, because a clastic (fragmentary -- sand, pebbles, etc.) sedimentary rock derived from volcanic rock sources may differ in a chemical analysis only slightly from the original volcanic rock. It is a common problem to distinguish between a primary volcanic ash deposit and some kind of volcaniclastic sedimentary rock. There should be some chemical differences between them, but given the poor understanding of weathering processes on Mars (past or present), it is little tough to make predictions about what the chemical differences will be.

The microscopic imager may be of greater use here, because it may resolve details of the bedding that will distinguish how the material was deposited. Some of the pictures already show some strange "ball-shaped", better-cemented structures that are eroding out of the bedrock and are accumulating on the surface. These could be pebbles (i.e. sedimentary) or they could be lapilli (volcanic structures formed by the sticking-together of ash particles). They could also be zones of cementation that developed long after deposition (e.g., concretions), in which case they do not say much about conditions at time of deposition. The latter two are more likely, because the "balls" are so spherical (most pebbles are not so perfectly equidimensional).

Anyway, people seem to focus on the quantitative chemical analysis instruments as the ultimate tool, but they only give bulk compositions. Chemistry only takes you so far. The imaging is at least as important, and it is complementary to the other tools. For a good field geologist (which these rovers are supposed to emulate), a hand lens is more useful than an APXS or Moessbauer spectrometer would be, but it is great to have them all along.

Looking for the obvious

[Pogue Mahone]

From the title:
Spirit grinds Adirondack, looks for iron

It's right there in the middle, between Ad and dack. Silly of it not to spot that right away ;-)

Re:saftey?

[noselasd]

No. When Spirit encountered problems(the flash memory), the software sat a flag.
The flag indicated that the rover shouldn't drive anywhere regardless of what commands it gets.
Now that the memory issues are hopefully fixed, the engineers forgot to clear the flag.
Naturally Sprit wouldn't perform the commands to drive.

More at http://www.spaceflightnow.com/mars/mera/040208rove rs.html

Images.

[noselasd]

Those interrested in images from the rovers should perhaps bookmark
Mars Exploration Rover Imagery.
Nice and updated page with all the latest images.

Microspheres

[bluyonder]

I noticed that two of the micro images from Opportunity had overlapping coverage so I added them together into a red/blue anaglyph. Take a look here. (sorry Chris)