I agree, that particular image really reminds me of roots of some sort (though obviously if you zoom in, they're not really roots). However, in this other pictu

I agree, that particular image really reminds me of roots of some sort (though obviously if you zoom in, they're not really roots). However, in this other picture http://en.wikipedia.org/wiki/File:Mars_Global_Surveyor_1.jpg http://en.wikipedia.org/wiki/File:Mars_Global_Surveyor_1.jpg the structure really looks more like a Diffusion Limited Aggegrate ( http://en.wikipedia.org/wiki/Diffusion-limited_aggregation http://en.wikipedia.org/wiki/Diffusion-limited_aggregation ), which can also be generated by non-living chemical processes. I'm not sure if these two pictures are of the same phenomenon, actually?