[X] My Assistant

[dvandorn]

According to our best models, Mars' axial tilt varies from its current 25 degrees to as little as 15 degrees and as much as 80 degrees. With an 80-degree tilt, it seems pretty obvious that the rotational poles will lose *all* of their residual ice caps and that polar conditions could exist almost all the way down to the equator.

So, for a significant fraction of the geologic history of Mars, areas that are not now subject to a polar climate were covered with dense caps of water and dry ice.

So... since we know (if our models are correct) that Mars *must* have huge areas that were once polar, what kinds of terrain alteration ought we be looking for as remnant indicators? If current polar geology is any guide, I'd think you would see surfaces covered over with the layered deposits that form as dust forms films between successive seasonal ice buildups.

What areas of Mars seem to be covered with such deposits? Do we have the kind of imaging we need to detect this kind of thing?

I will point out that Meridiani sure looks like it could be a candidate area...

-the other Doug