We got cleaned near to here as well..not just right over at those streaks...probably because of the high winds related to the start of the storm

Doug

I'd tend to agree Doug. I think it's logical to look at the cleaning events seen by both rovers before the storm as indicators that local winds were starting to pick up this time of year. Since less solar energy is reaching the surface now that the skies have gotten uniformly mucky, I'm not sure we can count on the wind to do much in terms of cleaning until this has passed.

Unfortunately, it looks like the deposition has already begun. Here's an L456 color animation of Opportunity's sundial, sol 1219 through 1259. Click through for the full dial image:


The brightness of the images isn't accurate at all, nor do I trust the magnet to be a great indicator of dust on the panels (the magnet is probably pulling down more out of the passing dusty air than is naturally falling onto the rover deck), but even the dial itself looks significantly dustier after sol 1235.

Nice animation Slinted as well as the dust deposition it shows how the shadow of the dial starts out nice and crisp and then blurrs almost to vanishing point and then starts to get sharper again.
Let's hope the shadow gets darker and sharper faster than the dust is covering the the solar panels.

Roy

Judging from the deposits on the sundial
http://qt.exploratorium.edu/mars/opportuni...W0P2124L4M1.JPG
the wind is blowing dust up the bay between Cape Verde and Cape St. Mary and it is falling out on Oppy.

Moving Oppy toward the tip of Cape Verde could help.

We don't know anywhere near enough about the local weather or the fluid dynamics of the crater topography to know where might or might not be good for cleaning.

Doug

All the evidence of winds we've seen in recent weeks has pointed to winds coming roughly from the north, so towards the rim rather than away from it.

On a related topic, after Rocker's post a few posts back, I've had this image in my head of a solar powered rover equiped with basic meteorological equipment, most importantly wind speed/direction, and perhaps a topographic model of its surroundings with the software to do some basic fluid dynamical modelling (yes, that's right; bear with me!). Then my image is of the rover caught in a severe dust storm, with array power dwindling, but the rover deciding where to park to maximize the power it receives, both in terms of incidence angle of light and in terms of winds that can remove dust from the arrays. Presumably it would be best to park with arrays tilted somewhat into the wind, in places where the local topography maximizes wind speed. The rover would have to decide if the energy required to drive would be offset by the power gain at the new location.

The point of this is obviously not a practical one - rover planners have enough on their plates already without having to put together such an elaborate scheme, which could be made moot with rtg's anyway. I just found it a compelling image, with the rover seeming like a living organism trying to survive, perhaps the way a lizard finds a good spot to bask in the sun, but must balance basking with the need to forage for food.

Or perhaps the long wait for the storm to subside is starting to affect my mind...

We may be entering the most dangerous part of the storm...when the dust settles. We don't know how much wind will clear the rover during dust settling.

Ya think?

How's about getting one wheel up on a rock, and letting it fall to shake some dust off?

Ummm, have you seen any large rocks on the plains of Meridiani? It didn't seem to help Spirit remove dust at Low Ridge...

That's a good idea; like that. One problem is that fluid dynamics requires a fair amount of computing power. Mind you, the MER team have done amazing things with such puny processors, so who knows. I expect most missions will continue to use solar arrays, with only an occasional large mission like MSL using RTGs (5 kg of Plutonium is not exactly easy to come by ).

You guys actually had me thinking about images I've seen of reptiles and insects which climb sand dunes in a South American coastal desert (Atacama?) to collect and drink condensing dew on their bodies from the onshore winds.

That may be more than we can expect from a Martian rover, but thankfully Opportunity had enough power to return some images today showing changes on the surface nearby.

It's not just you. I too find myself wanting to just go outside and sun myself on a hot rock.

Of course, that's not easy in Seattle . . .

--Greg

I suppose in Cosmics animation, the lack of change in the old tracks as opposed to the new tracks, is due to the loose dust from the old tracks having already been blown away before the storm.

Roy

On 6 July when Oppy reached Tau 4 and 255Whr we put out heads in our hands in despair. Now Tau 4 is a reason for rejoicing.

Out of interest, given the thin atmosphere and consequent small dust particle size limitation, just how much dust is there aloft?