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Unmanned Spaceflight.com _ Phoenix _ New dust devils spotted in old Phoenix images

Posted by: peter59 Apr 28 2010, 07:00 PM

On 20 April 2008, MRO spotted two dust devils at the centre of the landing ellipse, which measures 20 by 100 kilometres across. Based on the shadows the dust devils cast on the surface, researchers estimate that one stretched to about 920 metres in height, while the other reached 790 metres.



I noticed one very big column on picture ss141rad908730636 (Sol 141). This may be dust devil towering hundreds meters high, or .... artefact.

Posted by: AndyG Apr 28 2010, 07:26 PM

With the column on the right, there's an increased density on both edges of the funnel above ground level, which I'd expect to see in a rotating tube o' dust => not an artifact?

Andy

Posted by: JohnVV Apr 29 2010, 04:25 AM

peter59
???? by chance did you mean to post this i a year old thread ???
about working with a 32 bit image format on ( i think MS windows box)

that is very easy on *nix but not so easy on windows

Posted by: Explorer1 Apr 29 2010, 06:12 AM

For a few moments I thought you were implying that the dust devil is one and the same in both images, but I double-checked the dates and of course that's a month before landing.
Would be rather spooky otherwise. ph34r.gif

Posted by: Deimos Apr 29 2010, 03:19 PM

Wow. Quite real. Other dust devils have been noted in full resolution images: http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1799.pdf, and /or http://www.space.com/missionlaunches/080912-phoenix-dust-devils.html.

Meteorology-sensed dust devils as well as imaged one are discussed in a recent JGR (for those so inclined and with access). Abstract: http://www.agu.org/pubs/crossref/2010/2009JE003413.shtml

Anyway, I haven't heard of one (or, now, several) in one of the low-res horizon movies. And I like your enhancements to show details in the structure. Here is a contrast-enhanced version of all 32 frames. The dust devils show up late. You also see cloud and cloud-shadows moving around. I omitted time stamps, but it is about 50 sec per frame.

http://www.met.tamu.edu/mars/phx_enhanced_141_1FBC3R2.gif

Edit: well this is sad--the activity claims to be a deliberate dust devil search, which explains the low pointing compared to normal horizon movies, which look at clouds. So it should have been seen, oh, 540 sols ago...

Posted by: elakdawalla Apr 29 2010, 04:20 PM

I split the dust devil posts into a new topic. Well spotted, Peter59!

Posted by: mhoward Apr 29 2010, 04:51 PM

Wow. Can I ask a somewhat vague question: without the contrast enhancement, would the clouds look that dramatic to a human on scene? The contrast-enhanced version looks positively stormy.

Posted by: Astro0 Apr 29 2010, 10:27 PM

Wonderful enhancement work on those DDs.
Wish I had had the ability to do that kind of stuff way back when I first http://www.unmannedspaceflight.com/index.php?showtopic=5510&view=findpost&p=129001 a movie file of the tall DDs that appeared on Sol104.

Nobody believed me back then that they were there. Ah, vindication....it feels good. smile.gif laugh.gif

Posted by: stevesliva Apr 29 2010, 10:32 PM

QUOTE (Astro0 @ Apr 29 2010, 06:27 PM) *
Nobody believed me back then that they were there. Ah, vindication....it feels good. smile.gif laugh.gif


Laughed out loud at that one. Guess you need a plate-of-crow emoticon.

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