First, the re-projected overhead view. The anomaly is in the center of the circle I've drawn:
Next, a context map showing the one photo I have so far found of the area. The red bounding box show the footprint of the entire photo, and the white
bounding box shows the area that I've cropped out (next picture). This data is still the MOLA data, which is the only place the spike appears:
Now comes the area inside the white box in the picture above, to show the continuity from one to the next picture in locationg the area the feature is
in. You can't see the anomaly in this picture, but a comparison of the craters will show that it's the right area. The black bounding box shows the
area I cropped out of the full resolution (6m per pixel) photo:
Finally, the area in question at the full 6m/pixel resolution of the CTX camera:
If this were an actual feature on the Martian surface, the western half of it should be glaringly apparent at the rightmost edge of this photo, about
half way down the edge. I don't see it. I have to conclude then that it's a data artifact in the MOLA data, since that's the only place it appears.
For anyone interested in checking behind me, the CTX photo ID is B18_016839_1481_XN_31S286W .
Edit to add: For the CTX pictures, the sun illuminates the scene from the upper right, going by the shadows in the craters. Looking at the shadows
around where the "tower" should be, it becomes apparent that those areas are completely contained depressions, rather than hills or high spots. The
area I grew up in was a "karst" area - mostly limestone, in which water had worn out caves over the ages. we had depressions there that looked just
like those do, which we called "sinkholes". The cause of them was when a cave would collapse, the ground over it would sink as well, leaving a
depression where everything was "up" from inside it. I have to wonder what cause the Martian sinkholes? The only cause I know of is underground water
washing the "underground" away until the over ground collapses.
If they were impact craters, they would be round., more or less, instead of highly irregular as they are.
edit on 2011/10/24 by nenothtu because: (no reason given)