South Endeavour Crater - Page 16

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Barsoomer


Posts: 344

Reply: 301



PostPosted: March 23, 2018 8:02 PM 

Well, the solar panel is not that green, so they must definitely be enhancing the green channel, for whatever reason.

LWS


Posts: xxx

Reply: 302



PostPosted: March 23, 2018 8:06 PM 

here's my take on your sol 5034 image above

Winston

LWS


Posts: xxx

Reply: 303



PostPosted: March 23, 2018 8:10 PM 

Oops! that should have been sol 5034 above.

Here's another one from that series.

Winston

Barsoomer


Posts: 344

Reply: 304



PostPosted: March 24, 2018 12:50 AM 

Thanks, Winston. The images in this area are very appealing and I hope the rock in your 303 gets examined further.

I think I know what is happening with the green enhancement. I don't think it is intentional. My guess is that the images are taken with an automatic exposure setting designed so that the overall or average brightness from each filter is about the same. However, this introduces an artifact in the case where large areas of the image are dark for a particular filter. The exposure time will be increased to compensate but this will exaggerate the filter color in other areas.

In the present case, it may be that the soil is very dark in the green wavelength, so the rest of the image, i.e. the rocks, is biased towards green. This might mean that the real color of the soil is the complementary color of green, i.e. a mixture of red and blue, which is purple. (But it may be a rather dark purple.) The solar panels would be more grey in that case.

Barsoomer


Posts: 344

Reply: 305



PostPosted: March 24, 2018 7:34 PM 

Ah, my previous post is misleading in that it ignores the fact that L2 and L7 are not actually red and blue---they are infrared and ultraviolet. So the soil may not really be purple; it just is highly reflective to both IR and UV.. Then the green areas may actually be green. They look better that way, anyway.

Barsoomer


Posts: 344

Reply: 306



PostPosted: March 24, 2018 9:11 PM 

Closeup of part of hyper-eroded rock area seen in previous posts. Presumably the dark sand is related to erosion of the vesicular rock. Did the dark sand exit from the vesicles? Is this really a volcanic rock? An APXS study might answer that.

Barsoomer


Posts: 344

Reply: 307



PostPosted: March 24, 2018 9:46 PM 

http://plantsinaction.science.uq.edu.au/content/122-chlorophyll-absorption-and-photosynthetic-action-spectra

https://en.wikipedia.org/wiki/Pancam

Chlorophyll would reflect strongly at the L2 wavelength as well as well as L5, so it should probably look orange or yellow rather than green in a pancam L257 composite. It should look green in L456.

Barsoomer


Posts: 344

Reply: 308



PostPosted: March 26, 2018 10:44 PM 

A scene in L257.

The same scene in L456. The colors look more or less the same but are more vivid in L257.

Note the mound of fine dark sand associated with the apparently eroded rocks. It is hard to escape the conclusion that the fine dark sand is produced by the erosive process, and that the erosion is facilitated by the light-colored coatings on the rocks. The wind may also play a role, judging by the seemingly preferred direction of the coatings.

Barsoomer


Posts: 344

Reply: 309



PostPosted: March 27, 2018 9:40 PM 

The tailings from the rathole look purple in this L456 (closest to RGB). Also, the dust thrown onto the rocks by the rover track (on left) looks greenish. Not sure what it all means.

John Radogno


Posts: xxx

Reply: 310



PostPosted: March 28, 2018 10:26 AM 

Some interesting polygons in the rathole. At least 2 classic pentagons, and 2 more stretched 5 sided polygons (like top heavy caskets).

There is also a circle in the post image with looks similar to the berries we used to see that were half drilled. Any ideas?

LWS


Posts: xxx

Reply: 311



PostPosted: March 28, 2018 11:34 PM 

John;

Here's a stitched version of your reply 310 images.

The ratted surface do show what looks like sliced inclusions but they are somewhat of an enigma. The coffin-like one is strangely repeated at left top and bottom sides while there is just one roughly circular inclusion on the top middle that is slightly reminiscent of the numerous sliced berries of years ago in ratted holes.

I wonder what this would look like if they came back and imaged the hole a day or so from now. I bet it willed be filled up with gunk and there might be no sign of the inclusions we now see.

Winston

LWS


Posts: xxx

Reply: 312



PostPosted: March 28, 2018 11:58 PM 

Oops!

There are actually some berries of various sizes in the sol 5026 MI images. One small hollow one looks if it was sliced and shows something inside. The others look quite large but seem solid and are just embedded in the lighter soft matrix.

Perhaps Oppy might be able to do some research on the berries at this location.

Winston

Barsoomer


Posts: 344

Reply: 313



PostPosted: March 29, 2018 12:39 AM 

They did image part of that hole on both Sol 5033 and Sol 5036. I think the apparent sliced inclusions are still visible.

Here is a parallel-eye 3d of part of the area where the rock was ratted but pre-rat and pre-brush.

I have artificially colorized it to emphasize certain details. If you look carefully, you may see a few "Easter eggs."

Barsoomer


Posts: 344

Reply: 314



PostPosted: March 29, 2018 1:04 AM 

These images make it look as though the rover weight perhaps caused water to be expressed and then refrozen and mostly sublimated, leaving whitish residue. There is something odd about the stereo pair---it seems to me they don't quite match, even with a rotation.

Barsoomer


Posts: 344

Reply: 315



PostPosted: March 29, 2018 2:21 AM 

Several interesting things in this image. Less obvious are some tube-like "folds" in the rocks towards the top that seem to start at spheroid bumps. Some of them seem to have exit openings at the ends.

Barsoomer


Posts: 344

Reply: 316



PostPosted: March 30, 2018 1:49 AM 

We seem to have backed away from the area with the very interesting "pancake" rocks where the rat was used. I think the area is called The Island. I hope we return there after this side-visit to the hyper-eroded rock pile.

Barsoomer


Posts: 344

Reply: 317



PostPosted: March 31, 2018 11:37 PM 

The rocks could be volcanic, which would explain the bubble-like holes. The holes might also be explained by some kind of acid rain in the past. But why the fine dark sand?

Maybe a dune is just passing through and filtering through the rocks, but that seems unlikely! Perhaps "sand-blasting" by the wind and dust has an enhanced erosive effect on vesicular rocks. Or maybe some chemical or biological process is involved.

John and Winston---sorry if I interrupted your discussion about the rathole patterns.

Barsoomer


Posts: 344

Reply: 318



PostPosted: April 1, 2018 1:09 AM 

Looks like Oppy drove over one of the whitish things. What a mess!

Looks like some stuff stuck to Oppy and fell off later. Some whitish coloration on Oppy's deck. Frost? Or possibly some transfer of whitish material?

Did Oppy sink a little in her tracks?

LWS


Posts: xxx

Reply: 319



PostPosted: April 1, 2018 11:09 PM 

Here's a L456 image of some sol 5042 rocks.

Resembles coral rock to me!

Winston

LWS


Posts: xxx

Reply: 320



PostPosted: April 2, 2018 10:43 PM 

Some similar rocks from sol 5041. Note holey rocks and similar colours.

Winston

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