Created by taking the MOLA image of Gale crater (http://upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Topographic_Map_of_Gale_Crater.jpg/200px-Topographic_Map_of_Gale_Crater.jpg) and converting the colors to grayscale to indicate depth. The image was then used to create a heightfield from bitmap in Rhino3D, slightly smoothed (there are always artifacts from color replacement), converted to a mesh, the edges extended and sliced off to form a shallow box which was then merged with the surface heightfield mesh. Saved as an stl file, printed at 0.27 layer thickness with 1 shell, 5% infill, no raft or support. Some warping seems inevitable on my printer, but not too bad. At these settings took about 1.5 hours to print.

Will pair very nicely with ThePlanetMike's rover (http://www.thingiverse.com/thing:27908).

Sorry about the quality of the pic - printing in silver/gray ABS seems to enhance blobs and edges, particularly in photographs. Will try printing in natural and black ABS which tend to photograph better (and melt a bit more easily, reducing said edges and blobs).

UPDATE: I just uploaded a much smaller stl file - it has been smoothed (laplacian smooth) with Meshlab. Slightly less detail but much more manageable size. I'll try printing this afternoon.