Arch2008 said:
Apparently, during a Martian winter, sand particles can get stuck together and frozen carbon dioxide will cover them making a sort of “forest” from these structures.
http://www.bild.de/BILD/news/2010/0...ch-sind-das-wirklich-baeume-auf-dem-mars.html
That is such a strange and beautiful picture, from the HiRISE camera on the Mars Reconnaissance Orbiter. It was also part of the "Where in the Universe" series at the "Universe Today" blog, which many members here might enjoy. See
Where In The Universe #86.
The description of that "forest" is a little different. The forest like effect is not the frozen carbon dioxide itself, but streaks in the sand dunes left when sand is dislodged as carbon dioxide accumulates and sublimates again. From WITU#86:
This image shows a region of sand dunes in the high northern latitudes on Mars. The features that look like bristles, and actually streaks on the crests of the dunes. In the winter, a layer of carbon dioxide ice covers the dunes, and in the spring as the sun warms the ice it evaporates. This is a very active process, and sand dislodged from the crests of the dunes cascades down, forming dark streaks.[/color]
By the way, #87 has just been posted. If you like, pop on over to
Where in the Universe #87 and make a guess in the comments. Don't give links or details, just a brief guess, and then the answer will be up soon; probably about 12 more hours.
Cheers -- sylas