Space.com message boards had theories of this being ice
It looks more like fine sand or dust to me. Well worth checking out though! This temperture image does bring to mind some interesting questions.
Blue denotes cooler temperatures of about 220 degrees Kelvin (-63.67 degrees Fahrenheit or -53.15 degrees Celsius), and red denotes warmer temperatures of about 280 degrees Kelvin (44.33 degrees Fahrenheit or 6.85 degrees Celsius).
Another thing, I'm surprised we don't see more martian marbles in the crater. Look how many we see around the rim for christ's sake!
