The THEMIS images of Meridiani and many other areas of the surface show large territories that appear to have recently been wet -- well, "wet" in the sense that things are wet on Mars, not necessarily wet as our experience would lead us to expect.

It looks to me like this image (which is a remarkable one, to be sure) shows an area to the north and west of the Opportunity landing ellipse that was essentially a lake in the not so distant past. Again, we have to be careful to recognize that a lake on Mars may not be much like a lake on the Earth.

I realize that the lighter areas are areas of higher temperature not necessarily lighter colored terrain, but the outline shapes of these areas appear to trace shorelines. If the MOLA data show that these "lakes" are actually lower standing regions (I bet they are) then the case should be fairly strong that in fact there were lakes of some sort in those areas when time was.

Apart from the craters we see in this view, it looks startlingly like the view out an airplane window when flying over the Basin and Range regions of Nevada.

(Always understanding, of course, that Mars is the Planet of Mimicry.)

Thanks for posting this.

Cheers, BR