Robert showed a surprising cracked surface amid the Nilosyrtis Mensae <a
href="http://ida.wr.usgs.gov/fullres/divided/e03026/e0302633f.jpg">; here that appears to have covered an earlier rubbly surface.

The question arises: how does such a smooth (though cracked) surface get there? We see no obvious source for this relatively smooth surface. We note an apparent "shoreline" however. On inspecting the area further, we find another apparent "shoreline" with similar smooth and cracked surface material. We also seecraters scattered about some of which are partly filled with smooth material. Could this material (within the craters and along the "shores") have originated below the surface and been "erupted" (gently!) onto the surface?

On further exploration, we find a similar, if not identical, phenomenon associated with <a
href="http://www.msss.com/moc_gallery/ab1_m04/jpegctxmaps/M0200142.jpg">; craters in Utopia. (The same sort of surface is also found within craters in Acidalia, Arcadia and other Northern Plains regions). <a
href="http://ida.wr.usgs.gov/fullres/divided/m02001/m0200141b.jpg">Close inspection of the Utopia crater fill will show that the cracking is associated with pits. Pits are also found among the cracks on the Nilosyris surface. The pits in this Utopia crater could be sources for outgassing, which would suggest relative warmth and relative wetness at one time.

The question then arises: "What is this material?" Is it mud? Is it some sort of volcanic material? Is there a way to find out remotely?

So many questions!

Cheers, B R Felix