Sol 2 : HiRiseorama and UHF bugs. Options

[Reed]

Regarding the HiRise picture of the back shell and parachute, it seams to me that the backsell hit the ground North of the actual position (dark patch) while the heat shield hit SW of the actual position. Could it means that the chutte (so, the wind) dragged the backsell to the actual position? Does anybody see the same?

It does look that way. My guess is that this due to horizontal motion as it hit (which might be due to wind), not dragging by wind after the fact.

On the communication issues:
Not mentioned in the press conference, but AFAIK Mars Express also has rely capability, as a backup backup

[JRehling]

Thanks Fred! That really helps show the effect of the thrusters on the terrain. It looks like virgin unaltered surface (on the surface) is a little too far from the lander for the arm.

What makes me hopeful is that there's also such a big splash around the backshell. The boundary of the discoloration may signify the disturbance of a VERY thin and superficial layer of dust, which isn't what Phoenix means to study, anyway. So we may see that everything more than 1 cm down or so is still pretty virgin.

[ugordan]

So we may see that everything more than 1 cm down or so is still pretty virgin.

And if the soil is somewhat sticky (e.g. similar to ordinary regolith), it may even be less than 1 cm. It could be that just the finest of dust grains were picked up by the exhaust. Any fine dust deeper in (immediately below the surface) would be shielded by larger grains.

[imipak]

A probably-naive question(s): why would the effect of the thrusters be to darken, rather than lighten, the surface? Does it confirm there's little or no ice in the upper layer of more firmly consolidated regolith, immediately below the 10-20mm superficial dust on the surface, or is it just down to the grain size? (I believe very small thin films of ice on sand-sized grains don't necessarily lighten the appearance at HiRISE resolutions?)

[Juramike]

What makes me hopeful is that there's also such a big splash around the backshell. The boundary of the discoloration may signify the disturbance of a VERY thin and superficial layer of dust, which isn't what Phoenix means to study, anyway. So we may see that everything more than 1 cm down or so is still pretty virgin.

There might also be a bit of sorting of the smaller pebbles and grains (visible on the surface).

You might be able to look further from the lander to determine the effect, but this will be confounded by the natural sorting that occurs on polygonal terrain.

Vertical mobility, dig it!

[ugordan]

Imipak, I believe it's the same reason why dust devils leave dark streaks. Notice the backshell also has darker soil around it and it had no engines.

[imipak]

the same reason why dust devils leave dark streaks.

Ah yes, of course - thanks!

[djellison]

Surface
-----------
Fine Dust
-----------

Basaltic
Sandy
Soil

----------


Icey Soil


---------

Ice-T



Maybe....just guessing

[Juramike]

False color image I made of the HiRISE Phoenix lander image:



Dark blue shows the extent of the thruster (or impact whump) effect.

-Mike

[volcanopele]

Nice false color. Definitely suggests that the dark splotch around Phoenix is due to removal of the dust top layer rather than a chemical change.

[elakdawalla]

Surface...

I hope it's not

Surface
-----------
Fine Dust
-----------

Basaltic
Sandy
Soil

----------


Icy Soil


---------

Ice-9

!!

[Nix]

I just tuned in after a very tiring day - but glad I still did -I never expected the parachute-shot to be THAT spectacular, and having always loved those oblique images, well.. I'm speechless.

Nico

[tim53]

Tim, if you're reading this, can you report the exact lat/lon coordinates of the landing site? I tried to ask here in the press room and they got me someone to talk to who was telling me how important it was for this mission that they landed at an Alaska-like latitude rather than a Florida-like latitude Not quite the level of detail I was hoping for...

--Emily

Hi Emily:

I was told: 68.218830N 234.250778E, IAU 2000 Areocentric

I will update my map as soon as I figure out how to convert everything over to ArcMAP, so that I can incorporate the HiRISE images at full resolution for the whole map.

It looks like my career of finding landers before the orbiters can take pictures of them is over! ...but that's good, actually. Man, what a great camera!

Now, we can all start looking at the MPL search images with a little better idea of what a Phoenix-like lander looks like on the surface of Mars. But throw in a little more dust!

-Tim.

[glennwsmith]

I know this is a little off-topic, but Dot.DK, I agree with you that the oblique Hirise image is quite dramatic, and I am also wondering if this experience with Phoenix will incite the Hirise team to take more such images. . .

[elakdawalla]

Do you think it would be as dramatic without the parachute to give it a sense of scale? That was a once-in-a-lifetime shot.

--Emily