I found this very interesting. Scientists are very puzzled. https://www.yahoo.com/finance/news/something-unexpected-happening-those-mysterious-163417488.html
Looks like mold to me... But the fact that it brightens when it faces the sun, while it's misty, it gets brighter. And the fact that when it faces away from the sun, or when the mist evaporates, it gets dimmer. It's sort of like this stuff has algae or plant matter in it. Maybe it's a new life form blooming in a small pocket of water-ice + mist after getting up-thrust through the crust?