A whirlpool of thick, shiny blue paint swirls around this composition’s center. Deeply scored lines of pink mark each successive layer of rotation. The whirlpool’s edges seem to have flung deposits of salmon and lilac-colored paint, which is bordered by gray dotted with mustard-gold craters. You’ve probably guessed this is more than an artist’s fantasy; it’s a map of the northern polar plain on Mars, a permanent ice cap. The spiral troughs are formed by powerful downslope winds.