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Posted by: Bjorn Jonsson Apr 22 2015, 12:06 AM

Viking 1 and 2 obtained many well known images of Mars. I suddenly remembered an image of the crater Yuty, didn't remember seeing more recent images of it and became curious to see what it looks like in more recent images. The well known Viking 1 image can be seen on this Wikipedia page: http://en.wikipedia.org/wiki/Yuty_%28crater%29

What's perhaps not so well known is that the contrast has been greatly exaggerated, making the crater look deeper and the central peak higher than they really are. This is the original image:

And enhanced contrast - but not nearly as much as in the well know version of the image:



The most interesting images for my purposes turned out to be from Mars Express' HRSC since they show all of the ejecta around the crater and they are in color. To show all of it I had to mosaic two observations, h1143 and h1154. This was unexpectedly difficult as there was a big difference in color; I'm not sure if this was due to variable atmospheric conditions, something with the calibration and/or camera or both (probably both). I had to tweak the color significantly to get a seamless mosaic. I have some doubts about the resulting color but it shouldn't be too bad. This is a part the result, a hi-res grayscale image colorized from lower resolution RGB data:

http://www.mmedia.is/bjj/images/mars/yuty_mex_h1143_h1154.jpg

This image shows a lot of interesting terrain. For some reason I find the terrain near ~(1700,6600) (and SE/SSE of this point) very interesting. As far as I know there are no HIRISE images of this terrain but I'll probably check for HIRISE images of comparable terrain elsewhere (i.e. near other rampart craters).

This is just a small part of the mosaic (it's 63696 x 10665 pixels). Yuty is rather far north in a mosaic. Here is very different terrain from the southern part of the mosaic:

http://www.mmedia.is/bjj/images/mars/bright_terrain_mex_h1143_h1154.jpg

To show most of the terrain in the big mosaic together with the associated HRSC DTM I made an animation which starts in the south and ends with a close look at Yuty and the ejecta. Vertical relief is exaggerated by a factor of 2:

https://vimeo.com/125630557

And here are two anaglyphs showing vertical relief in and around Yuty. I find the vertical relief associated with the ejecta especially interesting:



More data is available for this terrain from MGS, MOD and MRO. There is a HIRISE image that crosses Yuty and some CTX images. There are THEMIS images as well but I haven't found any RGB images of Yuty from THEMIS, only monochrome images (and there are probably IR images as well). There are some MOC images as well. This was my first image processing project involving the Mars orbiters for years. This has been very different from processing images from the outer solar system (most of my image processing projects have been from Voyager, Galileo and Cassini data), the difference being that lots of high quality data from many different spacecraft is available.