Image PSP_007676_1385 is shown as a illustration of sand dunes, but I feel the most significant features are the two Ice Mounts at the bottom of the image where the sun is shining on the sides and lighting them up. They are not craters, they are raised ridges of ice. I suggest they are a completely new feature, a form of ice volcano where the underlying water is forcing its way to the surface and creating a flat topped circular feature; a round hill if you like. Now, look at the bottom edges of those two hills and they show blue ice and if that is true then the other features in the image that look like sand dunes may instead be ice features caused by the wind creating circumstances that allow the otherwise frozen water vapour, like you get from freeze drying, to form such solid features on the surface.

But the most important part is that if you have an ice volcano on the surface, you have liquid water under the surface…… Food for thought?

Cheers, Ian

Good article Ian, I enjoyed it and appreciate your efforts. I subscribe to Sky & Telescope and Astronomy magazine, Your articles fit right in as it is impossible for monthly pubs to list all that is happening now.

Ian

"the Mars dunes bare a striking resemblance" should be 'bear'

It's a pity for bad spelling to spoil an otherwise good article.