If you want to get in some snowboarding on Mars, you had better hurry up and get over there. The planet is already busy thawing out for springtime. NASA released an image taken by the Mars Reconnaissance Orbiter in mid-January showing sand dunes from the northernmost reaches of Mars as they begin to shed their winter coats.
Instead of snow, the dunes are covered with carbon dioxide ice, better known on Earth as "dry ice," the stuff you throw in a punch bowl for a Halloween party.
In the photo, the white parts are the dry ice coverage and the large dark swathes are the south-facing slopes that are getting warmed up by the sun. It's not much different than what happens on our planet when the seasons change. Mars is, however, spared the oncoming blast of spring allergy season.
The dunes can be fairly steep, causing sand to slide down and further clear off spots of dry ice. Any aliens on the surface won't be breaking out the swimsuits and pina coladas, though. The average temperature on Mars is still well below freezing. Keep that in mind when you're planning your next interplanetary spring break trip.