What is this nicely machined part, the cylinder lower right, imaged about a dozen times on Sol 30?



Just noticed there must be at least two of them pictured, for they were taken by the SSI, azimuth 305 and 167.

A sol 29/31 comparison (using ugordan's sol 29 image shown above as a reference)

Click to view attachment

Possible light layer seen in the far "wall"; the dark layers may be some shadow effects (low Sun angle) from a couple of rough ledges. Also some more shallow excavations and/or and impression of the scoop - see the "vertical" lines pattern. The "normal" pattern appears to be the "washboard road" horizontal ridges produced by the scoop "chattering" (?) over the harder underlying surface (or maybe showing the resolution of the steps in scoop's control?).

No more white layers, and some new dark splodges that seem to bear no obvious relationship to either the light or dark ones from sol 29, but maybe associated with the sol 29 white layer?

Airbag

This is only speculation right now, but since in wonderland we dont see the bright material that we see in the dodo-goldilocks trench and the arm struck a solid surface in the wonderland trench, could we be seeing a higher ratio of soil to ice in wonderland?. Could that explain those dark sploches?.

sol 8 - 31 comparison of lander leg:



Yikes!

Full frame comparison here.

WOW! that is interesting indeed . Any possibility's that the legs were covered by dust on landing, and wind is slowly blowing it off?. looks like ice to me.

Looks like a play of the shadows to me.

What exactly are we seeing here?
I see a brighter illumination in sol 30, but, beyond that, I am totally underwhelmed by the changes.
I would have expected much more. What substantive changes can be seen?
Where is "ice" disappearing?

Hi 105, should be part of LIDAR station (look to official CG video, is very clear that laser beam exit from it!)

Looking at this leg after 31 sols it crosses my mind "what adhesive was used here"?

There are three of them - they are where the uprights of the landing legs came thru the lander deck before they were deployed.

The LIDAR laser has been imaged, but that's not what those images are of. The LIDAR laser is much smaller, closer.

Doug

I love low-Sun-angle shots like this, don't you..?

P.S. This week's "Carnival of Space" is being held at 'Slacker Astronomy'. Some Phoenix-related posts on there.

Perhaps this leg was not manufactured according to the agreed specifications.

Soddit, our college has blocked access to that site. You can brief me on any special goodies this evening.

Wow, Horton, thanks for that blink comparison!

Weird indeed. My impression is that there's some post-landing gunk on the strut, and it's encouraging frost formation on the spots. The illumination angles don't look too different. IIRC, the atmospheric temperature gradient is horribly steep on the downward slope once you go up from the surface; maybe it's just enough to make a difference, assuming the soil spots aren't very good conductors of heat.

Alternatively, could the descent engine exhaust have caused chemical 'burns' on the strut with slightly different thermal properties? Sounds unlikely, but I'm just throwing out ideas here.

I'm surprised no one has yet commented on the fact that they're now filling in gaps in the Peter Pan and maybe going on to a new panorama. The new name? "RePeter Pan." GROOOAAANNN!

And I haven't a clue what's going on with that landing leg. I think you can say that there's no drastic change to the exposed ice surface at Holy Cow. But I'm flummoxed as to why the landing leg should look spottier now than it did before. I'm disinclined to believe it has anything to do with windblown anything because there's been no obvious wind-induced changes in the dig sites. So I guess frost might be more plausible, I suppose it's always dark and cold under there. But I'm unconvinced.

--Emily

I took me a second to figure this out, hahahaha. They're hilarious!

Here is the sol 8-31 animation under the lander with exposures for sunlight.

I expect UA / JPL / NASA to show their properly calibrated RAD version "soon" demonstrating changes to the surface of the ice in direct sunlight.

Here's a comparison showing the activity in the Wonderland site on sol 32. There is a wide area of newly exposed 'dark stuff' from the sol 32 scraping.


Sol 31

Sol 32

Sorry there's no animated gif, the limited color pallet couldn't handle the variations from the moving mast shadows.

Nice color renditions, slinted!

My version based on cylindrical map projected products:

Wow... they're really stepping up digging operations...

Pretty sure that's wrong too: the gear were stored through three holes in the Science Deck.

My guess is that they are the hard points that attached to the aeroshell (maybe with spring "pushers" to get a positive separation?). Note the two little caps standing up with springs behind it - I'm guessing that's where the electrical/telemetry umbilicals would have come out.

Paul

Edit - fixed my goofball link, added 1101001's original quote

This is why I'm inclined to believe that some soil splatter stuck to the strut, and these in turn may be acting as nuclei for frost formation. Crap sticking to struts happens all the time on aircraft landing gears, even in arid environments, although one big reason for this is that they are lubricated with hydraulic fluid. The basic post-flight inspection checklist includes wiping down landing gear struts for all aircraft I've dealt with. Anybody know if a lubricant was used for Phoenix's struts?

At the risk of resembling the 600-lb gorilla in the room, by what mechanism do we see water ice sublimating away out of the shadowed bottoms of trenches and yet putatively accreting onto the landing leg structure? If the temperature and pressure are such that the water ice will sublime in the shadow of a trench, I would think that just being shadowed under the lander wouldn't change the conditions enough to not only prevent sublimation, but encourage deposition.

I'm more inclined to think that the two images are basically identical, the later one with a far different lighting angle that highlights every little lump and bump of dirt blown onto the structure during the landing.

-the other Doug

If I've got my geometry right, the landing leg with frosty(?) spots should be in shade pretty much all day, while the vanishing ice chunks in the trench would have been in direct sun for much of the mornings (and closer to the ground, so warmer for that reason too). Those chunks probably went through cycles of sublimation and redeposition at evening/night, until sublimation won and they were gone for good. Maybe deposition is winning on the shaded legs.

Agreed. Those who don't need to show some careful measurements of what has changed.

I'm fascinated by the different rocks visible around the lander, and this mix caught my eye... lots of smooth, featureless rocks of roughly the same size, with some much more rugged-looking, weathered rocks laying amongst them... I know these rocks are pretty common around the lander, but this little scene just caught my eye...

Click to view attachment

Any geologists want to explain the differences? I'm guessing the smooth rocks are local, because there are so many of them, and the other rocks are ejecta from elsewhere..?

Have you seen the Horton amimations of the underside?

http://www.flickr.com/photos/hortonheardaw...in/photostream/

http://www.flickr.com/photos/hortonheardaw...in/photostream/

http://www.flickr.com/photos/hortonheardaw...in/photostream/

What alternative explanations would you suppose? P'haps a gleyed soil? <g>

--Bill

I know that there is absolutively no relation here, but these dark areas are very reminescent of mottles in a hydric soil.

--Bill

If you look at the sol 31 image carefully, you'll notice that the leg nearest to the RAC is beginning to suffer the 'frosty mould' syndrome.

The leg is also shaded but why doesn't it have as much frost as the other shaded leg. Is it because it is not well shade as the other or is it something else?

Everybody seems to take this is frost as an established fact. Isn't it a little too hot for that yet, the temperatures don't drop below some -80 deg C at night and CO2 frost needs -130 deg C IIRC?

Err... I'd been thinking H20 frost, not CO2...

Looking at Hortons closeup flicker gif of the spotty leg, there are spots towards the lower left end of the leg that appear darker than the leg in the sol 8 view but lighter than the leg in the sol 31 view. It's very hard to imagine different lighting explaining that. H20 frost nucleating in the shade on spots of soil kicked up during landing sounds reasonable.

From this update:

Have they actually used the rasp? I'd have expected it to leave an obvious mark.

Looks to me like, rather than the rasp, the flat section within the larger trench was possibly made with the secondary blade of the scoop.Click to view attachment

You may be right about the secondary blade. But to answer my own question, could these be rasp marks?
Click to view attachment
(Cropped from slinted's sol 32 colour composite.)

I don't think so, those marks are at the end of each line of trenching. It may have been caused by the rasp as the scoop rotated at the end of the trench but a doubt it was intentional rasping.

I think that is just a unfortunate choice of word relating to the scraping. Rasping would not 'flatten the layer' as the sentence reads, the scraping would.

I think the unusual markings shown in the Sol 31 image referenced in http://www.unmannedspaceflight.com/index.p...st&p=119357 may be caused by the secondary blade; that also explains why the soil appears to be raised as compared to Sol 29 closer to the lander as the action of the secondary blade would push some soil ahead of it instead of scooping it up out of the way like the main blade would.

Airbag

It may be goofy (since it didn't come up until now), couldn't that single contamination of one leg be caused from the released hydrazin after landing? The freezing point of hydrazin is about the same as water. Is that valve close to the leg?


Edit: I see!

Hydrazine wasn't vented after landing, only helium used for pressurization was.

A Sol 032 late afternoon mini-pano (from half-res images) looking towards the eastern solar panel; the SSI shadow is present again.

Click to view attachment

Airbag

Did a quickie experiment with a pretty new pic pair of an old trench.
One version's the regular red/green/blue composite, the yellower version's infrared/red/green.
The scraped and powderey looking ice is darker, but still blue at the shifted wavelengths.
Water ice is more strongly absorbing in the near IR (photo IR) than at red wavelengths. The result is pretty much as expected.

Sol 33 color with fudged data gaps:

Thanks for cleaning up the gaps ugordon (what a mess!), your images looks flawless.

>(what a mess!)

Would they be planning to re-transmit later, or are these images "WYSIWYG"?

--Bill

Commands to resend the missing packets are routinely generated. However, with the normal flash limitations, lower priority "sent" data rarely still exists when the commands get there. Sometimes the stripes are filled in with an ODY retransmit request; other times "bested" DSN data arrives later with fewer missing packets. Generally, they should be filled in within a day or two if they can ever get filled in.

So was this a Phoenix -> ODY dropout or ODY -> DSN?

Finally some more vanity shots of the deck and various thingamabobs, can't wait until someone mosaics this...

Same here! They are all part of the full Peter Pan I guess. Huh, in that lower left image some of those parts look like the air filter and fuel line of my lawn mower...

Airbag

Heh... there are actually automatically generated mosaics already, although they seem to clip the brightest pixels to zero and give weird effects. Color cylindrical projection here (75% full res, 900 KB). Yes, this is most likely part of the (Re)Peter Pan and probably would be more fitting in that thread.

Technically this is known as the Deck Pan and has a different ID from Peter Pan. It also doesn't have the full resolution R1 like Peter just the ABC downsampled.

I'll certainly be trying to get it into the Peter Pan of course.

So in contrast it actually has a proper red channel?

I can understand why they used RA on the deck, the R1 gives funny colors for the blue cal target as it verges into the infrared quite a bit. I do find it a bit peculiar that the downsampled frames are less sharp than their full-res counterparts (and I'm talking about more distant objects as well).