...No hollower then mine...I'm half Irish & half Bosnian (or Croat...still not sure), born & raised in a town that had over 200 bars with less than 40,000 people back in the day.

(Yeah, definitely bringing my credit cards, though...he is, after all, a poet as well...)

Nprev, what town would that be (while we're waiting for some ice to be dropped into the newly -- and fully -- opened TEGA door)?

Ah...Butte, Montana, still after all these years the very best place to be on St. Patrick's Day.

Back when I was a kid, the green draft beer (Lucky brand) was free at most places uptown on that day, and if you could see over the counter, you got served. If you weren't wasted by 8:00 AM, you weren't trying very hard...

Well, I'll add just one more comment -- maybe Brad isn't looking! -- I live in New Orleans -- and I'm one fourth Irish! But ... Nprev . . . ahem . . . as I was saying . . . what do you think the PH of the water ice will be?!?

Whoops -- forget that question! This is TEGA, not the Wet Chemistry Lab . . .

I look forward to a definitive read on the organic content.

Mmm...frankly, I doubt that there will be much if any, but that's my personal bias at work. Think that the surface photochemical processes are pretty aggressive, and that they tend to decompose complex organics very quickly. Soil mixing in this locale is presumably quite active due to the annual polar frost deposition, so I doubt that there's anything of interest organically less than a half-meter from the surface.

Would be very happy to be proven wrong, though. If we knew, we wouldn't have needed to launch Phoenix.

I think I should set your mind - and your bank manager's mind - at rest here Nick; I certainly don't have hollow legs, in fact my younger brother must have taken 80% of my legs' capacity when it comes to alcohol storage. He's a legendary beer monster. Me? After 3 or 4 pints I'm usually quite happy. So no credit cards needed, fear not!

TECP on the ground again.

An anaglyph of the RA (Sol 57).

From this update:

I can't wait to see calibrated colour images of these changes...

Actually, that might be a pretty handy way to concentrate any of the salts or organics mixed in with the subsurface ice.

Scrape up a bunch of subsurface ice, dump it in a pile somewhere and let the water-ice evaporate and concentrate the non-volatile organics and previously dissolved minerals.

Whatever's left would be the freeze-dried concentrate of the ice layer. ("just add water and stir...")

(Doing this trick for two different exposure periods would show if there were any time-dependent changes.)

-Mike

From the update, I understand they'll do the opposite!
And they want to image !!!

Yeah, the next sample should be most pristine, quickly gotten and hopefully minimally-altered ice stuff.

I was suggesting for one of the future samples (hoping everything is still working OK!)

[cross-fingers, toucher du bois, etc., etc.]

Love the oil-on-water effect on this one...

Click to view attachment

It actually looks very similar to when I wear my glasses and look through the edge of the glass (although I think that's caused by chromatic aberration)

From the new Planetary update:
This is interesting. It also explains why the rasp holes ("snakebite" pair) were so close to the top edge of frames like this one. I wonder how far off the rasp holes were from the intended location...

Just been making an anaglyph of a very rocky area imaged on sol 57 (example here), and noticed down at the bottom of the frame that there appear to be more than a few holes and markings on the rocks in quite a small area. One hole actually looks to be in the ground itself, and not in a rock, so I'm wondering if maybe some little meteorites came down here and the holes are "zap pits"..?

Just thinking aloud, wondering if anyone thinks it might be possible, that's all...

I'm not sure, but I think some of those dark areas might be shadows cast by protuberances of the rock.

Thanks for taking a look JM. I think some may be too, but the hole on the top of the large rock looks a lot bigger and sharper-edged than all the others, and the feature at the base of the large rock looks a lot like a small crater to me too... Might be wrong, fully prepared to be, I just thought it was curious...

3D

Are meteoritic "zap pits" possible at all on Mars. I would think that the atmosphere on Mars (even if it is thin) must stop the small meteorites responsible for the zap pits that were observed on the Moon. Even supposing that they don't burn up completely, those sand-sized particles should be slowed down quite a bit.

I seem to recall at least one "zap pit" having been imaged by Sojourner as it trundled around the Pathfinder landing site... and don't forget Oppy has seen a couple of meteorites sitting on the ground at Meridiani...

I remember the meteorite near Oppy's backshell. It was quite large and looked worn from its passage through the Martian atmosphere. I would be surprised if very small meteorites (+/- millimeter size) could make it intact all the way to the Martian surface.

Surely a thin atmosphere means there's more likelyhood of meteorites, large or small, making it to the surface?

Anyway, back to the picture I wanted opinions on... Maybe "zap pits" was the wrong term to use, sorry. Too precise. "Very small craterlets?" instead?

If it was that thin, landers wouldn't need heatshields, would they? Remember that on Earth, meteors burn up IIRC at heights of around 100-80 km, which is comparable in pressure (not sure about actual density which is what really matters) to Martian surface pressure. Martian atmospheric scale height is higher than Earth's so the density drops off slower with altitude.

A typical meteorite will hit Mars at a higher terminal velocity probably, but it will still ablate away considerably. The question is how small a meteorite can reach ground on Mars...

I agree with you that the proportion of meteorites reaching the surface is probably higher on Mars than it is on Earth. But at what speed do they hit the ground? Smaller ones arrive slower that big ones, I guess. But do small ones hit the surface at a sufficient speed to explode on impact and create a crater? I don't know enough to do the calculations.

Me neither, I was just, literally, thinking aloud after being intrigued by the things I saw on the picture. Thanks for all the input everyone. Interesting discussion.

And Mars is closer to the Asteroids belt...is that a valid argument ?

Deja vu all over again....

This reminds me of the protracted discussion on whether the small conical pits seen by Opportunity while crossing Meridiani were the result of micrometeorites or fragments from a meteor exploding before impact, or neither. I doubt that was ever resolved either.

FWIW, Mars also has a much lower escape velocity than Earth, as well as a lower orbital velocity, so objects intersecting its orbit obliquely will have a smaller incoming velocity on average.

Obviously, Mars falls somewhere between the Earth and the Moon in terms of to what degree the atmosphere filters out small impactors. But it's more like the Earth than like the Moon.

Frost evaporation at Wonderland?
7:16am: http://www.met.tamu.edu/mars/i/SS058ESF901...7_16770RCM1.jpg
7:46am: http://www.met.tamu.edu/mars/i/SS058ESF901...1_16770RCM1.jpg

Same filters, and only 1/2 hour apart so lighting is not too different, but there's been some scraping between frames. Still, the contrast between the bright patches and surrounding soil has dropped considerably by the second frame, even in areas that were not scraped.

I think you could be right.

Also, flicking between those two images, can I see the edge of the solar array flexing slightly as it warms in the morning?

Anaglyph of the rasp marks...

Could be. Or a gust of wind catching the array? Or, these are subframes. If the SSI pointing direction was a bit different between the two frames, but the cropping gave almost identical coverage of the ground (which seems unlikely), then you'd expect some "movement" of the array due to parallax. (I noticed such "movement" before and was about to post about it, until I realized it was just parallax, but in that case they were full frame so you could see that the pointing directions weren't the same.)

Colourised view of a lovely low illumination angle b&w...

Click to view attachment

Nicely done. Love your color choice. How do you decide for that low angle light condition?

Paul

I blink-compared the two and I agree that the Ultra-Flex is flexing slightly upwards while the ground bits move slightly laterally. I wonder if the tensioner that keeps the array bowed is released a bit as it warms up? Awfully short time for heating though. The ATK-Able folks would know...

Paul

Well, I could tell you, but I'd have to kill you...

No, to be honest, I literally just mess about. I know the experts on here have all these complicated and wonderful algorithms and processes etc, but I just put the image into PS Elements and play about with the colours and levels and highlighting etc until something appears on my screen that makes me smile and think "Yep, there you are... my Mars..." I've always said my images are pretty rather than accurate - others here do accurate so professionally and almost magically I wouldn't try to compete - I just tweak and play and change stuff until an aesthetically pleasing image appears. The 3D images are different, I try hard to get them as sharp and as clear as possible, but the colourisations... yeah, hands up, I'm a total fraud, no expertise whatsoever!

Latest colourisation of rocks illuminated by low sun...

Ha! You would! I'd steal it...


I hear that! That's really all we've got. I am surprised at how wide a range of colors there are on the official releases - I thought, once you have the target shot to go with your image you just tweak till there is Mars. But the experience of being on Mars is what we really want. I've talked to many of the crew that have flown in space and it is remarkable the degree to which their visual experience is very different from the pics they take. One guy tried to never take pictures of stuff that blew him away, just so he'd keep that complete image in his mind.

Mars colors kill me anyway. I was the NASA Artist on the Viking project at JPL and was supposed to do a painting of the craft on the real surface it landed on. When the first picture came down, the sky was shown as blue. I even asked Sagan if that was the real color (but I asked it like a doofus: "Is the sky like it is?" - to which he replied "yes the sky is as it is" (translation:"Moron: the obvious remains obvious"). When I finished the painting, it had to be authorized so I showed up at Tim Mutch's area and he informed me the sky was all wrong. It was pink. So I wrecked the painting to make the sky pink, showed up again at Tim's and he tells me the sky is now salmon. Okay. I think it ended up being butterscotch.

So now I'm revisiting a traumatic experience and trying to do this cool midnight view looking downsun. I am nowhere close to getting "my" Mars. So I thought I might steal yours (you would get credit...)

Paul

Just got my 3D specs from Stu (now there's a buddy...you're my hero, man, never change!!! ), and finally got caught up with the anaglyphs. Wow. Wow. Wow. Had no idea the trench was that deep, nor how undulating the landscape really is. (This one is my fav, though...)

Re soil cohesion: Yeah, there's something sticking that stuff together, all right. Amazed at how sharp-sided the trench is. The Viking digs were very, very crumbly and rounded around the edges...nothing like this at all. I wonder if the subsurface ice is sublimating during the day and refreezing at night at microscopic scales, clinging to soil grains? If so, we should presumably see the sides to start to slowly collapse over time.

Seeing Mars in 3D is quite a revelation, isn't it? Now that you have the glasses, don't settle for viewing single images in 3D. Crank up MMB and instruct it to generate 3D panoramas of your favorite MER locations for your viewing pleasure. You'll be amazed.

Glad they arrived safely Nick. Seriously, Mars will be transformed for you now, it's like exploring a whole new world once you can see 3Ds...

Meanwhile, over in 2D land, poor Snow White is looking really battered now...

Stu,
The colour may not be 'real' but your OM of those little particles is the prettiest picture to come out of all the Mars programs.

Do you want some sublimation?
Here is a animated gif for sol 36 46 62, even if the solar angle is different there is definitely ice dissapearance.


Click to view attachment

I just noticed on this picture the excess cabling that had to be tied back.
1. You'd think it was a weight penalty.
2. All the extra extra bends could be a fail point.

Cableing on the scoop.

Oh I just realized that's the scoop in the testbed, the flight model might be neater.

Thanks for the colour frame, Stu. I'm impressed with the absolute positioning accuracy for the arm: They've put the new set of (16?) rasp holes almost perfectly between the first set of 16. That's sub-centimetre accuracy!

Teck - I've been watching and the sublimation rate at Dodo/Goldilocks has dramatically slowed from the early sols. Perhaps it's reaching an equilibrium, with sublimation matching frost depostion?

Heck, you don't need an animated GIF, that last image clearly shows that the icy parts are deeper now than the non-icy. Check out the shadowing along the edge.

Well, this is pretty old news for us folk, but in this new update they discuss the changes between sols 21 and 44:

I'm a bit surprized by the cracks claim - my best guess was tracks left by pebbles - we can see some have moved between the frames.

Sure is, and if my hypothesis is valid then so will every other dig in this area over time.

Hmm. Going out on a limb here. The North Polar region (Vastias Borealis) is very smooth and quite broad in terms of surface area, while the South Polar region really isn't, except at very high latitudes, and even then it ain't the same. Impact cratering rates would presumably be statistically equal for both regions. There does seem to be a mechanism for autosmoothing of terrain in the north, namely subsurface ice exposure/sublimation/mass repositioning. Does this mean that subsurface water ice is preferentially concentrated in the North Polar region....and, if so, why?

I understand that the Southern Hemisphere is orographically higher than the north, but does a difference of just a few millibars of atmospheric pressure at most make that much of a difference in the behavior of ice sublimation/deposition? The hemispheric dichotomy is puzzling, even considering surface topography. Is there a similar dichotomy in crustal composition between the poles?

I'll add another question: how much mass transfer of moisture is there between the poles?

Does Mars have a global circulation or could the water be hemispherically locked somehow?
(i.e. The North has it's water vapor, the South has it's water vapor, and never the two shall mix)