Bright Flares from Scraped Rocks!?, Spirit Pancam saturated by Wheel-scraped Rocks? Options

[Shaka]

What's with the recent Pancams of HP surface rocks scraped by the stuck wheel?

Reflections in some areas are so bright that the image flares dramatically. I've never seen this before from Mars rocks except in tiny spots on Comanche rock. Only man-made metal surfaces on the rovers and heat shields have dazzled like this.
The flares occur in both the left and right cameras and also in some Navcam shots. What are these rocks made of that they would reflect so brightly? Can there be accidental overexposures under unusual light conditions?
Can some "Image Mage" explain this as an artifact?

[tty]

My immediate reaction was mica, but there are several minerals which can reflect like this. Pyrite for example which is more likely than mica from a chemical point of view.

[Bill Harris]

I noticed it too, and I've been snagging Pancam images with many more examples of these specular reflections. Tis indeed unusual, and now the observation is in the hands of the Rover drivers. We need to see other perspectives of this phenomenon. They really stand out viewing as stereo pairs.

My first thought is that this is a hydrothermal area and these are sulfide deposits. Not to be overly dramatic, but this may well be the El Dorado of the mission.

--Bill

[Shaka]

Pyrite for example which is more likely than mica from a chemical point of view.

Hee Hee! Thar's GOLD* in them thar hills, podnuh!


*(fools')

[ElkGroveDan]

A large faceted crystal will catch light that way, especially if you are using a flash in a cavern (I have examples from years gone by, but darn if I haven't gotten the slide scanner yet.). If this was on Earth I'd suspect quartz or halite (I won't even mention CaCO3). But I haven't been following the complex chemistry on this side of the planet.

[mhoward]

FWIW, here's the context and a view of the same area from a different perspective. In the second image, I have blue arrows indicating where I think the "shiny" rocks are.

[Shaka]

It's all good, guys, but can someone put together a "true color" version at this stage? It'd be nice to know whether the glitter is white or yellow or whatever.
It was mentioned before that one of the PIs found volcanic glass in HP rocks. Could higher concentrations of that glass produce a shiny reflection? Seems logical.

Newest Pancams focus on one of the rocks:Flare Rock

Can one of our codebusters check out the name of the rock? Hopefully this is our next destination.

[djellison]

can someone put together a "true color" version at this stage?

Without the calibrated RAD imagery, no.

Your best bet in the meantime is to keep an eye on this page - http://pancam.astro.cornell.edu/pancam_ins...true_color.html
Doug

[Shaka]

Thanks, Doug; it's bookmarked. Wow, I was amazed at the lack of contrast in those images - like everyday was in the worst of a duststorm, or a salmon fog.
Is everyone satisfied that they are the closest to what we would see if we were standing there? I mean in a spacesuit with a clear visor.
Anyhow, I hope some of our guys can scoop them with the approximate Exploratorium product. Damn, I'm panting for some MIs of that rock!

[dvandorn]

My first thought is that this is a hydrothermal area and these are sulfide deposits. Not to be overly dramatic, but this may well be the El Dorado of the mission.

See, I've been saying that the features along the boundaries of HP looked to me like the fine laminations you get at the edges of hydrothermal vents since last Martian fall. It's be really nice to find some mineralogical support for it!

BTW, last I heard (again a while back), there was still a pretty committed contingent on the MER science teams who favored a hydrothermal vent theory. I know we have a few people from those teams who post here on occasion -- can any of you comment on the thinking of the science teams as of late?

-the other Doug

[djellison]

Is everyone satisfied that they are the closest to what we would see if we were standing there?

You can argue that one all you like (and you probably will, but not in this thread). No two people see the same scene exactly the same anyway. It's the MER's team best approximation. If you want a different persons take on it - try Dan's calibrated set that you can get via MMB - he has a different tack on it. The perception of colour is, at the end of the day, a rough, artistic science. There's a lot of science and many algorithms behind it - but it's essentially a judgement call at the end of the day. Different eyes, different monitors, different lighting conditions - none of which are calibrated. I have two screens at work - on one of them, Mars always looks crap - without fail. It just can't do justice to those colour ranges. My personal preference ( which is what this has to end up being ) is about half way between Dan's and the PC team.

Doug

[Bill Harris]

See, I've been saying that the features along the boundaries of HP looked to me like the fine laminations you get at the edges of hydrothermal vents since last Martian fall. It's be really nice to find some mineralogical support for it!

BTW, last I heard (again a while back), there was still a pretty committed contingent on the MER science teams who favored a hydrothermal vent theory. I know we have a few people from those teams who post here on occasion -- can any of you comment on the thinking of the science teams as of late?

-the other Doug

And I've heard speculation that it is a volcanic glass, the idea quoted obsidian. It is likely not obsidian, since that "mineral" is derived from a felsic (rhyolitic/granitic) magma and everything we've seen here is basaltic. I'm not terribly hot on ig/met pet, so I'm not sure what is a basaltic volcanic glass. My initial and gut-ish intuition is a sulfide, since we have iron and sulfur and heat in abundance here. But this bright luster is significant . Not only do we have the major flare-producing rocks, there are aslo many small areas of "sparkle" visible.

One idea I've had is that we have an aluminum wheel that is locked up and being dragged. Could it be that the aluminum is rubbing off onto the hard rocks? That sounds unlikely, but I thought I'd toss it out.

Not subscribing much to conspiracy theories, but in the two L257 trios that have come down, each pair has a "data loss" area on a channel. Not unusual, it happens. But usually, the black data loss area has a fuzzy "jpeg border", and these two occurances have pixel-sharp data loss area borders, which is very unusual.

So much for the X-Files, we now return to the arena of rational discussion.

--Bill

[slinted]

Thanks for your kind words Doug. I take as high praise being as far from your aesthetic sweet spot as the pancam team.

Unfortunately, there will be no true color to be had from the brightest parts of these images. Sometimes, the bled out spots in the raws are just an artifact of the stretching, and the real detail is there in the originals (Tyrone comes to mind...compare the original to one made from the PDS files). But when you see blooming around the object, like we're seeing in the latest pancams of these bright rocks, you can be pretty sure the calibrated files will be bled out too. All we'll get from these images are constraints on the brightness (no less than "x").

[Del Palmer]

Not subscribing much to conspiracy theories, but in the two L257 trios that have come down, each pair has a "data loss" area on a channel. Not unusual, it happens. But usually, the black data loss area has a fuzzy "jpeg border", and these two occurances have pixel-sharp data loss area borders, which is very unusual.

The former is caused by transmission loss, whereas the latter is due to sub-frame masking (deliberate removal of certain image areas before transmission). In this instance it's a way of managing the blooming issues.

[Bill Harris]

There is a series of partial-frame L456 Pancams online. Most are of the solar cell deck but there are a few of the locked-up wheel and specular-reflection rocks-- evidently they are assessing the health of the Rover before heading off of Homeplate. One of the L456 color trios shows what certainly looks like aluminum from the locked-up wheel being scraped onto the rocks.

This does not bode well. As long as the wheel is intact and being dragged, the Rover should be driveable. But once the wheel wears through to an "open shell", the drag will markedly increase and she'll lose a great deal of mobility. Goddard/vonBraun may not be reachable, and they may be faced with the decision of where to park Spirit to transition from rover to sessile station...


2P246746085EDNAVQWP2291L4M1

--Bill