Robot Arm - Observations and Excavations Options

[Doc]

I dont think thats ice. Wouldnt we see signs of sublimation (smoke)
They ought to get a series of pictures to see the changes if its ice.

[eeergo]

I don't think smoke would be seen if it was ice: it's cold up there and sublimation wouldn't be too fast or spectacular... snow on Earth also sublimes and we don't see smoke coming out of it. Just my view, not necessarily correct, but I think so.

[nprev]

Wouldn't the ability of any 'smoke' to be seen from sublimation be a function of atmospheric relative humidity in a addition to pressure & temp?

Don't think that the met package measures humidity, but I'd be very surprised if the RH of the air was anything but extremely low, which IIRC means that the H2O molecules would disperse too rapidly to form visible vapor.

[tasp]

Visible 'plumage' from exposed ice would depend on local relative humidity, optical depth of the column you're looking through, mineral content of the ice itself (dissolved materials would effect freezing point of the material and the resulting rate of sublimation), wind speed, thermal input to the ice, sensitivity/noise ratio/dynamic range and compression of the camera, temperature of the atmosphere, shading from the vehicle, possibility of contaminants in the ice to form 'crustage' and probably several other factors it is too early in the morning for me to think of.

For those so inclined, you might want to consider an outcropping of dirty ice under Phoenix to be a cometary phenomena. A little more bang for the buck for the mission!

[tasp]

LOL.

See what happens when it takes me 10 minutes to compose a post first thing in the morning without coffee. I get pre-empted by nprev.

[ustrax]

If that is ice...that is GOLD!!!

The Heimdal image is great but this man...this is what we were looking for...

DIG!

[DDAVIS]

'Visible 'plumage' from exposed ice would depend on...'

One important factor would be Sun angle. Presenting a chunk of previously buried Mars ice to the Sunlight with a camera fairly near the shadow of the sample could possibly reveal comet like plumage against the dark sky due to forward scattering, if it isn't windy.

Don

[nprev]

Just out of curiousity, with respect to the viewpoint of the "ice" image, which way did Phoenix come in from horizontally? Seem to remember that there was some horizonal motion just before touchdown.

Reason I ask is that the exposed area doesn't look like it's directly underneath a thruster set; could have my perspective all wrong, though. Also wondering if this stuff might be shallower then we think; haven't seen any significant 'dunes' of blown dust around Phoenix from the motors.

[bcory]

All I can say that it seems to me that whatever it is, the sun glare/reflection is highly indicative to me of ice.

And as a Canadian I know ice!

[ilbasso]

What's the size of those patches relative to the other polygons that we see on the surface? What's under the polygons on Earth's permafrost? Would we expect similar plates of ice?

[scalbers]

It was interesting at Friday's news conference how Ray Arvidson showed a similar image from Viking 1 (link below) very near the lander that was duricrust. He said he's still rooting for ice with Phoenix though the scientific method should be followed to find out. The crust does look more uniform in the Phoenix image that would support ice.

http://www.jpl.nasa.gov/images/phoenix/col...-v2_800-600.jpg

Steve

[Marz]

Assuming those plates are ice [w00t!!!], then are there any estimates for how old it is? Does this ice ever melt and reform annually, or has it been this frozen block since the last time the north pole was warm enough to melt ice (is that around 10 million years?).

I second the command to DIG!

[MahFL]

The Phoenix site seems down

[bcory]

The Phoenix site seems down

It got hacked by a Russian last night

[Decepticon]

If this does to turn out to frozen water, will this end the Naysayers of there no water on Mars!?