A closeup of Pando's comparison.

More likely oxidation Doug so hot hydrothermal isn't necessary to the process. Interestingly enough Mn deposition has been connected to the authigenic formation of Fe-rich smectites such as nontronite. Fe-Mn oxyhydroxides in hydrothermal fluids can undergo early diagenesis with smectites being the Fe sink and with Mn precipitating, principally as nodules. So the high manganese reading dovetails with the smectites identified from orbit.

An excellent point. the only way out of the conundrum seems to be we simply haven't seen the actual disturbed area from which PI originated,
unless it just so happened to be picked up and transported inside the wheel to be released in a perfect ready-to-roll configuration in order to get to its resting place.. that all sounds more plausible the more I think about it. but did the sequence of wheel maneuvers support such a scenario?
otherwise I hope its indeed ejecta and perhaps the source a new priority destination.

whatcha know.. this discussion is getting some press:
http://rt.com/news/mars-rover-rock-appear-650/
http://www.news.com.au/technology/science/...e-1226803349096

http://marsrovers.nasa.gov/gallery/all/1/p...EOP2596R1M1.JPG

There is another disturbed area imaged on Sol 3544.

I check Curiosity Rover's Raw images every day, I forgot about little Opportunity. Interesting how that rock got there.

I was searching for information on where it may be headed next? Once it has observed this location after the hibernation time. I can't find much on it.

"Hibernation" is a strong word - Oppy should be able to keep working all winter, although probably not driving too much. As for what's next, check out Tesheiner's post here.

Edit - Sorry, that link doesn't quite take me to the right page - Tesheiner's post is #314, on the previous page. (Is there a technical problem with linking to posts? I got the link from the "Post #314" on the upper right of Tesheiner's post.)

Gust of wind blowing across Endeavour on sol 3546, compared with a frame taken under very similar lighting on sol 3548:

I think this happens when posts get moved or deleted. The links can't cope with the renumbering that results.

Regarding the origins of the mystery rock, it seems possible that the accumulated torque of two wheels going from pigeon-toed position to straight-ahead could have had a hand in popping out a rock., ... well, after attempting to put it in writing, I think a simple GIF might say it better, albeit crudely:



Of course, the rocks would have to be perfectly situated and sticking out just high enough for the wheels to get a toehold, with one rock not willing to budge, the other more willing if properly persuaded.

(I'm aware of the many inaccuracies in the above illustration, such as wheel layout, type of rock I picked, and sure there are many more. I don't have time to correct them, just trying to convey idea of two rover wheels doing some prying-apart action. My apologies if someone already floated this idea!)

Here's something that Stu spotted that I think is quite interesting. It looks like a couple small rocks with long trails behind them. Stu created an animated GIF with lines next to the trail-like features; they're subtle. I looked up the images in MP for some context: the trails are not obviously downslope, they go more west-ish, although I suppose they could be a bit downslope locally, it's hard to tell. Stu gave me permission to post this to see what you think.

Are you aware that the front right steering actuator has been broken for 8 years? It doesn't steer - it's locked with 8 degrees of toe in.

Of course RF doesn't steer, but that still leaves three steering wheels. Walfy's idea actually sounds like the second good idea we've heard (after the obvious rock-popped-out-while-being-driven-over).

The basic problem is that Pinnacle Island moved a considerable distance, as the debris on its rover side indicates. The slopes here are fairly subtle, around 15 degrees. In Mars gravity, that seems to be too shallow for a rock shaped like PI to roll easily. So PI must have been given a kick somehow. Getting squeezed under a wheel, and now Walfy's idea are the only ideas that seem to work. (The wheel rotation speeds are so slow that I can't believe PI being trapped inside a wheel and then spat out. And the odds of a meteor strike nearby have to be incredibly small.)

I think the human eye is excellent at finding features like that, but I don't think these are trails left by rolling rocks. We know what disturbed soil looks like on Mars - I'd expect much more obvious darker patches due to the soil underneath being exposed (if these were recent, at least).

The turning of a steering actuator flicking a rock across the ground? Have you seen how slow the wheels steer? It's incredibly slow. Sorry - I don't buy it. Moreoever - how would a steering actuator throw a rock infront of the rover? Walfy's animation shows it being throw away from the rover....not right infront of it.

I don't know if it's ejecta...it does inherently seem unlikely - but it's not that far beyond the realm of possibility. The modern day cratering rate as derived from orbital discoveries is such that I believe it was characterized thus : Within the duration of one crewed surface mission of a martian year - statistically there would be a new impact crater formed within earshot. We've been here 5 martian years. It's far far from impossible that it could be a piece of ejecta. It could be a tiddlywink's like pinging of a rock from under a wheel. But a steering actuator didn't just flick a wheel several meters....I don't buy it.

http://spacecoalition.com/blog/new-info-mars-rock-mystery

"Candidate divot" hinted at in the interview. Which is good, indicating it's originally from close by and can be put in geological context.