MECA (microscope) Images Options

[CHOAM]

You can look at the grain shape, it's opacity, and it's color - but it's hard to make any comprehensive analyses based on only that information.

My first guess was salt or silica, but I'm no geologist, and Emily Lakdawalla has posted a more informed opinion on this:
http://www.planetary.org/blog/article/00001497/

Re. requiring a volcanic origin for silica: I'm guessing a grain of that size could be lofted and carried to a polar position, given a few billion years...


- CH

[dvandorn]

Isn't this the kind of thing that the atomic force microscope could help settle? Silica flakes and salt crystals have rather unique and recognizable structures at atomic force scales, don't they?

-the other Doug

[Airbag]

First sample sprinkled onto the microscope inlet:

http://www.met.tamu.edu/mars/i/SS017EFF897...5_12370R6M1.jpg

Hope not too much went into the far right wet chem sampler MECA inlet...it does have its own open/close valve, but what happens to material already in that little hopper? Or is it open at the bottom until the MECA valve is in the "accept sample" position, so that any unwanted material just falls though?

Airbag

[jamescanvin]

Sounds like the team is happy with the sprinkle into the Microscope.

http://phoenix.lpl.arizona.edu/06_12_pr.php

[ahecht]

The images of the first sample have come down. Click each image for a link to the full size:

phoenix.lpl.arizona.edu/images/gallery/lg_4869.jpg



phoenix.lpl.arizona.edu/images/gallery/lg_4867.jpg



phoenix.lpl.arizona.edu/images/gallery/lg_4859.jpg



phoenix.lpl.arizona.edu/images/gallery/lg_4870.jpg

[Shaka]

Interesting amber crystalline-looking particle (blue arrow).
I hope we see lots more.
Speculation time!

[centsworth_II]

Interesting amber crystalline-looking particle... Speculation time!

Cubic? With (if I may be so bold) a corner taken out.

[Shaka]

Cubic?

Oddly, I see a cylindrical 'hatbox', complete with lid, but then I'm a planktonologist with search "expectation" for centric diatoms.
NO, I don't claim it's a diatom!! I just mean I'm not the best person to identify it.

[fredk]

Interesting amber crystalline-looking particle (blue arrow)

We had a comment on that arrowed grain earlier in this thread - the left half of that image was from the first batch taken about a week ago, before the soil was sprinkled...

[imipak]

Am I right in my impression that the consensus is that any ice particles would have sublimed away by now? If so, can these whiteish particles or grains be anything else but salts?



(Edit, having seen fredk's animation of particles vanishing from the trenches in the other thread: I meant that isolated icy particles on this microscopic scale would have sublimed away )

[Decepticon]

The images seem a bit out of focus?

[SickNick]

The images seem a bit out of focus?

Decepticon,

They're trying to focus grains that are fatter than the depth of focus of the instrument. In the geological world, we take a rock, or a pile of grains, glue it all together with Araldite/Epoxy, cut a slice, and grind it down to less than 30 microns thick. We still have focus issues.

here, they're taking raw grains up to 1/10 mm size (100 microns) and trying to focus them.

Focus and resolution are not independent entities. if you want to "see" grains 1 micron in size - as we do, then anything bigger than 1 micron will be out of focus.

[Decepticon]

Thanks for that explanation!

[Airbag]

They're trying to focus grains that are fatter than the depth of focus of the instrument.

Yes, but the instrument is designed to take multiple (8) images at different focus distances, each with a depth of field of 50um. These multiple "vertical slice" images are then used on the ground to reconstruct an image where all parts (up to 200um deep) are in sharp focus, just as was done for MER's MI images, but on a much smaller scale of course. So I expect that eventually we will see images where all grains are in sharp(er) focus - assuming that was not already done!

Unfortunately, the Optical Microscope (OM) images do not show up on the otherwise very useful Phoenix SSI raw images directory web pages so there is no obvious way to tell how many "different depth" OM images have been taken and/or downloaded so far.

Does anybody know if the raw OM images are available online anywhere?

Airbag

[Decepticon]

So I expect that eventually we will see images where all grains are in sharp(er) focus - assuming that was not already done!

Even before I could ask It was answered!

I can't wait to see this!