Is it reasonable to propose that the surface of Mars has pretty much always been cold, through most of its history probably colder than it is now?

If so, then discussions of ponds and so forth -- at the surface -- become less than informative. First you've got to get a pond, lake, sea or body of water, and if you're dealing with a surface at 180K or whatever and atmospheric pressure at next to nil, the idea of liquid water ponding over extended periods is difficult to say the least.

Yet it could happen.

There's little doubt that the surface features are sort of familiar yet very odd, alien, and (so far as I know) not duplicated on the Earth. Something very different than commonplace terrestrial conditions gave rise to the features we see.

Somehow we have to think about Mars in Martian terms, and so far we have been almost completely unable to do it.

Let's look at some other sites on Mars and maybe get some clues to how the Meridiani features might be thought of in Martian as opposed to terrestrial contexts.

The south polar region is quintessentially Martian. It is the site of numerous oddities, from those Spiders to apparent sand geysers, to relatively thick deposits of clear CO2 ice. There is a lot of water there as well, frozen; possibly some is liquid below the surface. It's a very active region, as well. The changes wrought by this activity are swift enough for the photo processors to make little movies of what's going on.

Now could Meridiani once have had an ice cover (either CO2 or water or both) and could there have been activity at and below the surface? Could liquid water have been forced to the near surface (but not perhaps to the surface itself) by internal heat and pressure? The extent of the sulfate deposits in Meridiani appear vast, and though there might once have been an inland sea here, what other conditions might have given rise to the features we see?

If there was some kind of ice or other cover here, then the ripples in the rock (well... "rock"; I'd rather call it "deposit") would not have been caused by wind -- assuming the deposit formed beneath the ice. Water-formed ripples, sure, or at least fluid formed.

If all of this formation was always exposed to the surface, the question is much more difficult. It would almost require a much warmer surface and a much thicker atmosphere over an extended period, and wind and water would be expected to work together to shape the formations we see. But to me, there is very little evidence that the surface actually has been warmer than it is now over extended periods.

So how would these things work in an almost always cold environment?

Cheers, BRFelix