[X] My Assistant

[fallofrain]

While browsing images from the MOC, I came across this photograph. I contacted the Planetary Science Institute and the editor of an astronomy magazine about it. Their belief was that it is probably dust blowing from a crater. We all agreed that it is probably not a dust devil. I have no reason to doubt their conclusion. It is probably correct. But the romantic in me wants it to be something a little more unusual. An ice geyser, perhaps, or venting gas.

I've had at least a cursory look at almost all MOC images. I've never seen anything like this. Dust devils tend to move in nearly vertical columns. This appears to be blowing downwind from a stable point source. There is no evidence I can see of other dust features (dunes or devil tracks) in the frame. The width of this photo is 2.97 km. It's cropped from MOC image R1801150. Other than cropping, it hasn't been enhanced in any way.

I wanted to post this to see if anyone would like to make comments. So how about it? Any ideas?

[dvandorn]

Hmmm... I don't think I necessarily agree with the assessment that the image shows anything actively being blown out of the crater. If you'll notice, the two most obvious "lobes" are arrayed exactly radial to their origin point. If these were lobes of a geyser or even a windblown plume, I would expect them to begin to travel the same direction (downwind) when they got a short distance away from whatever physical feature was separating them. There is no sign that either feature is arrayed anything except radial to the origin point.

Also, while the two "plumes" located at about 3:30 and 4:30 (in clock-face angles) are the most visible, there are degraded remnants of very similar features at about 10, 11:30, 12:30 and 1:00 angles -- all exactly radial to the same origin point as the two prominent features at 3:30 and 4:30.

These may all have been created by windblown sediments, but it would appear to me that each of them would *have* to have been created during a time when the wind was blowing from a different direction than when any of the others were created. So, I've got to say, it's pretty obvious that these are all static features lying on the ground, that may well have been caused by dust plumes emanating from the crater, but I don't think any of them are actual dust plumes or geysers hanging in the air at the time the image was acquired.

-the other Doug