I think this is a splendid opportunity to put MARDI to good use! If the "Snow Queen" is its field of view (and reasonably focused) it would be a freebie to watch the ice sublime over time. From what I read on the site, it looks like it has a very wide angle lens. (66%) Just depends on the placement. Maybe the microphone attached to it could listen for sublimation!

I've enhanced to under-side image to improve visibility on the shadowed areas and I noticed an interesting thing on the lander leg to the left. It looks as some dirt has sicked to it. The interesting thing is that it's only on this leg, the others look clean.
Click to view attachment

Just for reference, the same processing applied to the previous "ice" images, here joined in a mosaic and averaged over the overlapping area to reduce compression artifacts.
Click to view attachment

Maybe the thrusters melted some of the ice and formed a slurry with the dirt and dust that re-froze and stuck to the lander leg

The whole point of the mission is to find Water Ice, remember this is frozen water you can melt and drink, not frozen carbon dioxide. Also to test the ice to see if it has been regularly melted, but with current summer high temps of -30 C that seems unlikely. Though at one time it does seem liquid water flowed all over Mars.

This JPL press release has a bit more detail about this fantastic find of "ice" including quotes from Horst Keller and Peter Smith:

http://www.jpl.nasa.gov/news/news.cfm?rele...lease=2008-090b

News Releases

A view of the ground underneath NASA's Phoenix Mars Lander adds to evidence that descent thrusters dispersed overlying soil and exposed a harder substrate that may be ice.


Camera on Arm Looks Beneath NASA Mars Lander
May 31, 2008

A view of the ground underneath NASA's Phoenix Mars Lander adds to evidence that descent thrusters dispersed overlying soil and exposed a harder substrate that may be ice.

The image received Friday night from the spacecraft's Robotic Arm Camera shows patches of smooth and level surfaces beneath the thrusters.

"This suggests we have an ice table under a thin layer of loose soil," said the lead scientist for the Robotic Arm Camera, Horst Uwe Keller of Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany.

"We were expecting to find ice within two to six inches of the surface," said Peter Smith of the University of Arizona, Tucson, principal investigator for Phoenix. "The thrusters have excavated two to six inches and, sure enough, we see something that looks like ice. It's not impossible that it's something else, but our leading interpretation is ice."

Phoenix site back up!

Some trivia: Most cyberattacks & viruses originate in Russia & Eastern Europe per Symantec. Might be an artifact of organized criime activities, and transiently high-traffic sites are an obvious proving ground for new methods. In other words, no need to take it personally.

We now return you to our regular program.

Normally, the surface of ice is plain, 90 degree to the gravity. However, the show ice pictures, the surface seems not to be smooth.
How can a water ice have rough surface.

It was down about half the day for me. back up a few hours now

Fox News even reported on this hacking at about 720 PM EDT (30 min ago), saying that initially a website story had been changed.

More importantly, they reported on the "ice" finding after a shuttle launch report.

CNN has reported on the shuttle launch , but not yet on the ice

Glad to hear that CNN is exercising some restraint on the "ice". IMHO, the possibility that this is ice should not be trumpeted to the mass media unless there is confirmation.

It's really easy to say something to the press, but REALLY hard to retract it, and if this stuff turns out to be duricrust or pavement-stone sedimentary rock al a Meridiani the Phoenix team will take a beating that they just don't need.

Take a look at natural ice in some glacier or in Antarctica/the Arctic... obviously, the surface of ice is flat so as long no distubing factors appear: different slabs of ice freezing together and crushing each other with the expansion (as in the Arctic), breakages for other reasons with later refreezing, partial sublimation/fusion by weathering, local impurities within the ice which may cause some areas proner to evaporate first... Well, I could go on, but anyone who's seen ice outside the fridge or a frozen puddle knows ice surface doesn't equal smooth shiny surface. In fact, it's preety rare when it does.

Accept here we're talking about permafrost ground ice.

Totaly different

For the record, CNN is reporting it, but thankfully using cautionary terms.

The ChemCam should be very helpful in this case. Did they ever think of shooting the ice using laser? Anyway the next few days are going to be interesting. I wonder if we're just standing on top of an iceberg

Thanks for your comments. I am starting to understand it and am convinced that the ice surface does not be necessary to be smooth.

Hope that RAC would take pictures not only one but the rest of two more patches below of rocket thrusters.

ChemCam is MSL, right? Anyways, from what I've heard, the science team is very interested in this artifact, and can reach the site with the arm of the lander. Should be quite interesting...

The polygonal surface of the soil is enough to tell us that we're seeing something other than platonically perfect concentric spheres, even if the deviation is only on a scale of centimeters. Which is to be expected. Although how it relates to terrestrial permafrost is unclear.

New images, is this a scoop mark in the soil?

http://phoenix.lpl.arizona.edu/images.php?...1114&cID=27

Now this one is cool, scoop, CD, and flag all in one shot.

http://phoenix.lpl.arizona.edu/images/gallery/lg_1103.jpg

Don't know why but it kind of reminds me of this child's book.

Kind of looks like a footprint.

Actually, it looked like a rock at first, and then my eyes readjusted so I could see it as the depression that it is. Definitely looks like a 'scoop mark' to me.

ElkGroveDan,

I thought you were going to reference this child's book:

http://www.amazon.com/gp/reader/0395169615..._pt#reader-link

Any speculation as to the cause of the hollows in this rock?
http://phoenix.lpl.arizona.edu/images.php?...1159&cID=27

Could it have been recently modified by a nearby heat source.

Sure looks like dirty ice, like what you see in the spring when it's melting off your driveway after a long winter.

Click to view attachment

Looks like channeling and definately a couple of vents. Hard to say if this is from the thrusters that acted like a blowtorch into the ice. Hard to tell, but doesn't seem to have much change in the pattern from the Sol 4 image. The artifact observed on Sol 4 is beginning to look like a spring of some kind.

I agree we've got to be cautious but, come on guys, such a rounded shaped will be hard to find in a rock

Don't forget duricrust.

It might be the RA 'touch' they were talking about on the Friday press conf to characterise surface characteristics.

Sorry to deviate from the excitement of ice for a moment...

Regarding the screw underneath the lander. Might it be an explosive bolt from the lander-backshell separation? Perhaps this particular bolt didn't explode exactly as planned.

Doug proposed it is related to the helium venting

I attempted to make an RGB image with one of the sol 6 RAC R/G/B LED illuminated images, but I suspect the ambient lighting drowns out pretty much any effect of the LEDs as the resulting image was still effectively greyscale. Any attempts to tease out more color information just caused the JPG artifacts to be enhanced. I wonder if they will use those LEDs at night? At least then there is no ambient lighting.

Hum, that gives me an idea - what if one were to subtract the "D" filter image from each of the R/G/B images first before combining them? That may work with the raw images but probably not with the stretched JPGs. Also depends on whether the camera uses the exact same exposure for each of the images or not - or at least knowledge of the relative exposures.

Airbag

Here is an observation that I will note I haven't seen here yet.

Recall that this area sees complete cover by dry ice every winter. Since we don't know what the deposition process was for the water ice, is it at least possible that there may be dry ice pockets within the water ice permafrost layer?

If so, a very small pocket of dry ice (or a few of them) could explain things like the rounded hole that appears to have been blasted out of the ice beneath the thruster bells.

Dry ice wil indeed sublimate very fast, almost explosively, in the current temperatures and pressures, no? We see it sublimating explosively and creating "dirt geysers" during springtime, which is colder than what we're seeing now.

So, if there are nuggets of CO2 ice buried in the permafrost, what further manifestations ought we be looking for (other than the possibility of Phoenix taking an unplanned-for hop)?

-the other Doug

But we do have relative knowledge of exposures! :-)

Open the orginal-size image in a text editor. It will start with something like this:


Looks like both SSI and RAC have this information. I was wondering if anyone could explain how it's possible to adjust the brightness (?) of RGB channels in Photoshop or ImageJ according to this information. Wouldn't this give us almost exactly the right hues without any human estimation?

Unfortunately, probably not. As slinted pointed out elsewhere, the jpg images are still auto-stretched to improve contrast (like MER, and I guess Cassini). Although we have some exposure information, we don't have the parameters that were used to brightness-stretch the public images. It's a bit funny, actually.

Adding: However, maybe something could be done with the auto-panos, I don't know.

Knowing the exposures doesn't help us really. That information is rendered useless by the histogram stretch. The ultimate raw image would also contain original DNs that were scaled to 0 and 255 respectively.

"Regarding the screw underneath the lander. Might it be an explosive bolt from the lander-backshell separation? Perhaps this particular bolt didn't explode exactly as planned.
------
Doug proposed it is related to the helium venting"
-----------------------------

Or the biobarrier?

(PS great mission so far! The pictures taken under the lander are very cool - I hadn't anticipated that. Remember when some of us were concerned this would be dull compared to the rovers? I'm frustrated I'm not in my office with Photoshop to play with. I want to make a circular version of the exaggerated relief panorama as soon as I get back)

Phil

Ah, OK. I forgot about the histogram stretch. So out of curiosity, what do the pros do about that? Is it something complicated that can't be easily automated? Is there a piece of information distinct from the image that tells them how much it was stretched?

They don't have to deal with it - they have calibrated data. The raw JPG's are just processed to be 'sensible to look at' not calibrated.

Doug

Thinking again about the ice, I have been wondering about something:

I am given to understand that the arm will dig down into loose soil, trenching, making tidy piles of soil, etc.
But given the high abundance of water here, isn't the soil going to be like plate of granite? Won't it be difficult or even impossible in this case for the scoop to dig?
The appearance of platy ice under that loose regolith undersores my impression that the "soil" will be really hard, except for the loose sandy top layer.

Idea: Why didn't they attach a convex lens to the end of the arm to zap ice into liquid/vapor via solar energy, then take a picture....

Thanks to all of you, especially Stuart, for this wonderful forum.

.

So do the originals hit PDS eventually, and until then the public just gets the raw jpgs plus press releases? Or do we not get the originals at all? This mission is so incredibly open and transparent, I hate to ask this, but why aren't the originals released as fast as the jpgs? (Sorry to be OT, but I'm interested.)

Two reasons really- one is that the science team want to be sure that the "real" data are properly calibrated and ready for scientific analysis before releasing them, so people don't jump to premature conclusions from preliminary data. The other is that exclusive access to the full data set for a few months is the reward the science teams get for all the work they've done to make the data possible. Till recently, most the images from most missions weren't publicly available in any form, except for selected press release images, until a year or more after the data came down, so the availability of JPEGs is a big step towards open access. And yes, the original data will eventually hit the PDS for all to enjoy, probably within less than a year.

John.

Of course: Anti-scoopage. Thank you.

Anti-scoopage is an important part of it, but that calibration part is really important too. They do a lot of work to characterize the camera before it flies, but the launch with all its vibrations, and cruise with its cold temperatures, and landing and operation with both, in the dirty environment of Mars, can change the characteristics of the camera in subtle ways, which they can't begin to understand until they've operated it on the surface for a while. So they need months to make sure that all the digital numbers in each image pixel are telling researchers good information about the way that the materials they see reflect light.

--Emily

Kind of hate to ask this, but if a given amount of scoopage contacts an equivalent amount of anti-scoopage, what happens?

(I'm truly sorry...just couldn't resist!)

One of the MRO engineers is continuing to post fascinating information concerning the problems with the MRO UHF radio (Electra) on his blog.
Here's a permalink, and another, for readers from the future.

TTT

Speaking of scoopage the arm has grabbed its first sample
http://fawkes1.lpl.arizona.edu/images.php?...1404&cID=28

Oh my!

So this is the scoop and dump, right? Still in that characterization phase.

Looks like it was scooped from the same area as the touch test http://phoenix.lpl.arizona.edu/images/gallery/lg_1428.jpg

If this was the scoop-and-dump, the scoop leaks.

Here's an image of the lander deck from the RAC at 11:12 local time:



And here's an image from 12:38 local time:



Note the small pile of soil sitting just inside the wiring bundle in the second image. In both images, the foreground reflective surface is the side of the scoop.

All subsequent images of this portion of the lander deck show this little pile of soil.

-the other Doug

Click to view attachment

False-color image saturated to 60%, of the RA scoop soiling it self .

whoa! Are the small clumps of blueish-white stuff in the upper-right portion of the image perchance ice?

I had a go at it myself - the LED's really work at this range - not so great imaging the surface at any sort of distance though.