Need help identifying Rover Images

[rohnds]

I was looking at Mars Rover photo and I came across these set of photo taken by Spirit using Panoramic Camera on Sol 1447 and 1436.

I have not been able to identify them. My first guess was that these are marks left by abrasion arm of the rover. Am I right? Or is there another explanation?

I would appreciate any help in identifying this.
Thanks in advance.

http://i252.photobucket.com/albums/hh6/myforumfotos/2P254819998EFFAX16P2514R1M1.jpg

Source:
Spirit :: Panoramic Camera :: Sol 1447
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1447/2P254819998EFFAX16P2514R1M1.JPG


http://i252.photobucket.com/albums/hh6/myforumfotos/2P253847452EFFAX10P2565L2M1.jpg

http://i252.photobucket.com/albums/hh6/myforumfotos/2P253847486EFFAX10P2565L5M1.jpg

http://i252.photobucket.com/albums/hh6/myforumfotos/2P253847671EFFAX10P2565L7M1.jpg

Source:
Spirit :: Panoramic Camera :: Sol 1436
http://marsrovers.jpl.nasa.gov/gallery/all/spirit_p1436.html


Rohn

[Nowhere Man]

I don't think it's a RAT hole. It's not completely circular as they usually are. Also, I'm pretty sure that by this point in the mission, the RATs were worn out to the point of uselessness.

I'd guess a blob of volcanic glass that has been eroded. Until someone digs it out, or the researchers address, guessing is all we have.

Edit to add: You double-posted this. If you're quick, you can delete the other thread before someone else posts to it. Otherwise, you can ask a moderator to kill it.

Fred

[ToSeek]

It definitely looks like the mark left by the abrasion tool. Other examples:

http://marsrovers.nasa.gov/gallery/press/spirit/20040207a.html

http://marsrovers.nasa.gov/gallery/press/spirit/20040301a.html

http://marsrovers.nasa.gov/gallery/press/spirit/20040309a.html

http://marsrovers.nasa.gov/gallery/press/spirit/20040331a.html

[01101001]

I concur. RAT.

The same rocks and hole are shown on 1431 (http://marsrovers.jpl.nasa.gov/gallery/all/spirit_p1431.html) pancam, more clearly, and the MI took the closeups on 1431 (http://marsrovers.jpl.nasa.gov/gallery/all/spirit_m1431.html), actvity witnessed by the front hazcams 1431 (http://marsrovers.jpl.nasa.gov/gallery/all/spirit_f1431.html).

Planetary Society: Mars Exploration Rovers Update: Spirit and Opportunity Begin Fifth Year of Exploration in Shadow of "Little Sasquatch" (http://www.planetary.org/news/2008/0131_Mars_Exploration_Rovers_Update_Spirit.html) has a false-color picture of the site with caption:


Spirit took this image of Chanute and the abrading it did with its rock abrasion tool on Sol 1442 (Jan. 24, 2008) with its Pancam.

[Nowhere Man]

I bow to your greater patience in examining more of the MER pix than I did.

So, are the RATs worn out, or not? 1431 sols is about 4 Earth years or 2 Mars years.

Fred

[01101001]

So, are the RATs worn out, or not? 1431 sols is about 4 Earth years or 2 Mars years.

On last legs. Still grinding though -- unless something's happened lately.

NewScientist: Mars rover hobbled as instruments show their age (http://space.newscientist.com/channel/space-tech/mars-rovers/dn12929-mars-rover-hobbled-as-instruments-show-their-age-.html) (2007 November)


In late 2006, Opportunity's rock grinder, or rock abrasion tool (RAT), stalled during a grind because an encoder had stopped working. Engineers fixed the problem by writing software to operate the tool without data from the encoder. "So we [have been] able to grind successfully with the device since then," Callas says.

Spirit's grinder encoder also stopped working recently, forcing the rover team to implement a similar software fix.

And now another encoder on Opportunity has broken down. This one monitors the brush that clears away rock dust produced by the grinder. The rover team have worked out a way around that as well, but accidentally rotated the brush the wrong way, bending the bristles.

Some testing is needed to make sure it is safe to continue using the grinder with the bent brush. "Our expectation is that we will be able to resume grinding operations with the RAT within a couple of weeks," Callas says.

Perhaps you recalled some of the status reports of problems, without catching news of the workarounds.

Oh, the partial circularity is probably just a lack of alignment of the plane of the RAT's cutters with the surface of the rock. The cutters just missed grinding the part that was a little bit farther away. I'm pretty sure I've seen that sort of result before. They probably try to avoid that but don't always succeed.

And, I had to suspect there were other images of the feature in the archives, so I looked with confidence. It was Spirit, and Spirit has moved only slightly since it found its winter resting place, just to adjust its tilt.