APF0000puh looks very interesting.

I posted by mistake in the 'help' section. Doh! More folks might appreciate it here 😃

I'm thinking the feature on the right hands side is either a very smooth bulge or it's not a surface feature, e.g. cloud or duststorm.

Posted January 8, 2013 11:22 PM

by AstroCam

At first glance I thought it was a large crater or basin, but I looked again and it does indeed look like a big dust cloud. I'm not sure, but it's very interesting.

Posted January 8, 2013 11:28 PM

by pocketmoon

Looking at the craters, I think the illumination is coming from the top left. So lighting/shadow suggests not a basin or bed of some sort. If it is a surface feature then it's very smooth - no impact craters (could be sand filled ?) but no dunes ? I wonder what the scale is in this image.

Posted January 9, 2013 10:26 AM

by michaelaye scientist

I will check from where the sun comes. This is indeed beautiful and fascinating...

Posted January 9, 2013 11:19 PM

by michaelaye scientist

In terms of interface and where to post: Each discussion page for each image has to the right "Help", "Chat" and "Science" discussion chats, so you can discuss science/findings there as well. If you want to raise it to people's attention that had so far not seen this image, then of course you have to go to the Discussion boards.
Thanks all for your help!

Posted January 9, 2013 11:21 PM

by michaelaye scientist

for a start, here's the original data page for this image: You can check out other products for this image, dig around a bit yourself! 😉
http://www.uahirise.org/ESP_020357_0950

Posted January 10, 2013 12:02 AM

by spamfree

Hi,

At what height are the photograph's taken of Mars in the Zooniverse Project ?
I can't get a feeling of the scale when I look at them .
Thanks,
Keith.

Posted January 10, 2013 10:48 AM

by pocketmoon

Thanks for the link to the source - there are a number of these features about 1/3 of the way down this image.
It looks like sand being blow out across the top of ridges in the same direction as the fans. The ridges run bottom left to top right and some are concave toward the bottom right. Could be wind shaped structures ?

http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/ESP/ORB_020300_020399/ESP_020357_0950/ESP_020357_0950_IRB.NOMAP.browse.jpg

Posted January 10, 2013 2:14 PM

by michaelaye scientist in response to spamfree's comment.

The height alone would not help you without knowing the telescope's magnification. I can tell you that each pixel is either 0.5 or 1 m (depending on the compression that was used at the time). But I actually don't know how many pixels are shown in the data on the site. Meg?
The height, for completeness is between 160 and 198 miles. http://en.wikipedia.org/wiki/Mars_Reconnaissance_Orbiter #Launch_and_orbital_insertion

Posted January 10, 2013 5:38 PM

by michaelaye scientist in response to pocketmoon's comment.

I'm not so sure if they are really concave or just have something different deposits on the ground there. Our brain's understanding of shadows often tries to infer 3D shapes from subtle differences in surface tones, so I wouldn't trust that feeling too much! 😉 Alas, I'm not geologically converse enough to discuss this much, but I do know that there can be wind-shaped dunes on Mars, so I wouldn't put it out of the question.

Posted January 10, 2013 5:42 PM