pedestal or not....(cont.)

here is a pancam view that has been processed using a (slightly modified) classic CLAHE technique
(seeing in shadows)

* The transition from shadow to light has a processing illusion that makes the shadow look depressed (ignore it)
* The other observation is that the jpeg compression in the uniform dark shadow becomes very apparent as the histogram is equalized...

my interpretation is that this just a pavement chunk that we have seen all over the planum. The pavement takes a jog to the left under BI so that it appears to be a vertical structure (i.,e. pedestal from the camera's POV) if you put your finger over that left jog under BI the illusion goes away and it looks like pavement. I am fairly confident that the left jog does not touch BI.

Another image from a different angle (move the rover) will add more data

...your mileage may vary...



cheers

I don't know if you've got it right or not, but your analysis is pretty much the way I see it. The imagery available is provocative, but we can't be certain that the feature being discussed is truly an erosional pedestal, protected by its caprock. I like your idea of using the MI for a closer inspection, but it would be very unusual for the team to use the MI for a task it was not designed for. I think it would also be quite surprising to see them using the rover to intentionally study "geomorphic" processes on Mars.

One would have to suspect that an overlying, resistant rock would tend to protect its base from aeolian erosion, but aside from this rock, we really haven't seen any other obvious pedestals beneath other resistant rocks in the region, or have we?

I'm going to jump on PDP's bandwagon, actually; that paving stone does look like it jogs to the left, and the underside illumination is tricky enough to play perspective tricks. More data definitely needed, though.

Re studying "geomorphic" features: CR, I think that if in fact this is a pedestal that would indeed be a significant finding worth detailed examination since it could tell us some things about the gross history of Meridiani. Not a Rosetta Stone by any means, but if the overall 'floor' has eroded since BI's been in place (however long THAT is) that would pose the question of why it's so generally uniform & level everywhere else we've seen. Eolian erosion usually doesn't produce flat surfaces; it removes it from one place & piles it up elsewhere (so I'd expect BI to have a tail dune). Furthermore, that might mean that even the local weather patterns have been extraordinarily constant for a very long time, and that might have some implications for the cyclical climate theories.

Whether it occurred before or after BI arrived, I thought the presence of the layer of loose berries on the surface indicated a meter or so of rock which once contained the berries having been worn away. Am I wrong in assuming that the loose berries indicate a 'proven' removal of about a meter of rock from Opportunity's stomping grounds (according to the mainstream hypothesis)?

I thought the theory here was that the northern plains (where Oppy landed) are blueberry-paved deposits formed as you described, with the deflation of a good meter or so of soft sulfate-rich sandstone that halted when the freed concretions provided an anti-aeolian "armor." The remains of the sulfate rock that was blown away composes the extensive ripple structures to the south (through which we're currently traveling). This terrain didn't have as many concretions buried in its sandstone layers, and so never developed the full armoring. Instead, ripple structures protect the remaining sandstone paving in the ripple fields from further erosion.

-the other Doug

Here's my attempt at an anaglyph from the sol 1961 pancam closeup of the big jagged pit:

This included a 20.7 degree relative rotation. The result still isn't perfect, but hopefully I've minimized headaches from viewing this...

Based on pics and Google Earth files posted in the Opportunity route thread, is Block Island just visible on a HiRISE image at full mag..?

Yes - it is - after all, Tim said it was

Really good - great sense of depth. Those two stalks sticking out at the bottom look really fragile. There's a couple or so more smaller similar structures around the edge of the hole. Fascinating. Anyone, any idea what sort of erosional processes might have been responsible?

Must have missed that post, sorry.

What are the HiRISE guys waiting to take a shot with Oppy?

Ok. Back to lurking...
Ermanno

I wonder if they started as products of the plunge onto Mars. Streamers of molten iron refrozen before impact. Or perhaps they were formed during the creation of the original asteroid. Of course, weathering on Mars would have taken place as well.

They're preoccupied at the time. But you're right, an MRO image of Opportunity at BI would be great.

"The powerful Mars Reconnaissance Orbiter (MRO) unexpectedly switched to its redundant Side B computer and subsystems before entering a protective safe mode on Thursday....'Taking the spacecraft back out of safe mode is one of the earlier steps in resuming full science operations, which is expected to take several days,' Webster added."

Catching up with recent drive direction mosaics.

All these link to the same page

Sol 1910

Sol 1912

Sol 1920

Sol 1942

Sol 1946

Sol 1947


James

And the Reeds Bay Pan:



James