[X] My Assistant

[fredk]

Update on the sol 1149 DD and images here.

From assessing the trajectory of this gust, the atmospheric science team concludes that it is possible that it passed over the rover. There was, however, no noticeable increase in power associated with this gust.

[alan]

Couple of dust devils caught by the pancam on sol 1169

http://qt.exploratorium.edu/mars/spirit/pa...25P2446L7M1.JPG
http://qt.exploratorium.edu/mars/spirit/pa...25P2446L7M1.JPG

[djellison]

We're just not in the right topography for a cleaning event I think. Maybe down the far side of Home plate or up near pitchers mound we might get something.

Doug

[Guest_Oersted_*]

how often must I say ....stop quoting a post in full in a reply. Doug

HOW OFTEN MUST I SAY THAT DUST DEVILS ARE NOT ASSOCIATED WITH CLEANING EVENTS!

[djellison]

I agree 100%. But they observed a strong gust kicking up dust. That is what I was making reference to.

[MizarKey]

There seemed to be a bit of activity over near El Dorado, even in the 'off season'. Too bad Spirit doesn't have fully functioning wheels, it would have been easier to drive somewhere windier and then back to the science targets...as it is now, they may be able to get somewhere where they can do science and pick up a gust. I doubt they'll get much on this side of Home Plate.

[slinted]

There were two single frames from recent dust devil movies that showed activity. They only showed up in one frame, so the links below are enhanced subframe versions of the individual images instead of the movies:

Sol 1166
Sol 1168

Since there was some confusion about what the new change-detection software would look like when used for dust devil movies, I thought I'd point out that these two (as well as the sol 1147 movie) look like they are products of the new software. The movies made with the new software have the sequence number 'P1562' (labeled on the pancam site as 'dust_devil_watch' for the first frame and 'Unexpected sequence!!!!' for any subsequent frames) and are full-frame navcams as opposed to the old sequence P1561 movies which were 256x1024 subframes. In time, we may see subframe 'watch' products, since it had been discussed that the new software could be used to reduce the size of the images returned by selecting only those parts of the images that had detectable change, but for now the full frames are being returned, probably for diagnostic purposes.

[imipak]

HOW OFTEN MUST I SAY THAT DUST DEVILS ARE NOT ASSOCIATED WITH CLEANING EVENTS!

"In the past, dust devils and gusts have wiped the solar panels of dust, making it easier for the solar panels to absorb sunlight."


I'm confused. (Film at 11!)

[djellison]

I refer you to the first Squyres Q'n'A where Steve says it was unlikely to be DD's as one of the cleaning events was at night. I imagine that's just the writer assuming what most people do

Doug

[fredk]

Dust devil visible to the south in the sol 1187 front hazcams. It's only visible as a darkening against the sky - we can't see its base, which appears to be behind Low Ridge. It's visible in both L and R, so it's clearly not dust on the lens. I think this is the first we've seen this season to the south. Here's a difference image between sols 1187 and 1189:

[slinted]

The images that came down today showed dust devil activity on sols 1180 and 1191:

Sol 1180 showed a long and very distinctive track on the ground in the last frame, following the passage of a large somewhat disorganized DD visible in the previous frame

B/W enhanced (3.3 meg)

false color enhanced

Sol 1191, around 2:30 PM (a little later then we usually see movies being taken) has a nice tall tight cone coming in from the right (if it's the same one as seen in the previous frame). This one is only 5 frames so far, hopefully we will have more soon.


B/W enhanced

false color enhanced

[atomoid]

Thanks for posting the DD movies, however when i was trying to locate the raw images for either, i cant find the most interesting ones on the NASA nor lyle.org sites..

i can see the first several DD images but the two images for 861 and 1076 seconds seem to be missing for SOL 1180.
wha happen?

[slinted]

atomoid, you might be looking at an older cached version of the JPL page. The last two frames are on that site now, although they were downlinked on a later date than the first ones. Here are the direct links :

http://marsrovers.jpl.nasa.gov/gallery/all...8F0006L0M1.HTML
http://marsrovers.jpl.nasa.gov/gallery/all...8F0006L0M1.HTML

[alan]

A big one:

http://207.7.139.5/mars/spirit/navcam/2007...AZP1561L0M1.JPG

Come on, the dusty rover is over here.

[sattrackpro]

"...it was unlikely to be DD's as one of the cleaning events was at night." - Doug

Well, while it is true that most whirlwinds form during warmer sun-lit afternoons, it is not true that this is the only time they form. We know that wind still blows at night (as implied) - and we know that craters of the right size, depth and formation create many whirlwinds that travel great distances before they collapse.

So statements that a whirlwind cleaning would be unlikely simply because an event took place at night - or statements saying that no whirlwind ever caused a cleaning event are both rather shortsighted and proof-less in my view.