A new extreme sport in which you float down a sand dune on a block of dry ice cushioned by gas has been invented - only you'll have to go to Mars to try it.
Mysterious grooves on the surface of the red planet had been baffling Nasa scientists until they theorised they could be created by such a phenomenon (minus the surfer).
Serina Diniega, a planetary scientist at NASA's Jet Propulsion Laboratory actually bought slabs of dry ice and slid them down sand dunes in Utah and California to confirm dry ice could act in such a way in the martian atmosphere.
These examples of one distinctive type of Martian gullies, called "linear gullies," are on a dune in Matara Crater
She found as the dry ice thaws, a lubricating layer of gas forms underneath meaning the slabs can move even on very slight inclines.
Diniega said: "I have always dreamed of going to Mars.
"Now I dream of snowboarding down a Martian sand dune on a block of dry ice."
The grooves, called linear gullies, are a few metres across and are relatively consistent in size all the way down with raised sides.
Diniega said: "In debris flows, you have water carrying sediment downhill, and the material eroded from the top is carried to the bottom and deposited as a fan-shaped apron.
"In the linear gullies, you're not transporting material. You're carving out a groove, pushing material to the sides."
The pictures were captured NASA's Mars Reconnaissance Orbiter (MRO). They were taken during the Mars winter when the gullies are covered in carbon dioxide frost.
The researchers theorise once the slabs of dry ice have slid down they sublimate into the atmosphere explaining the the abrupt ends.
Candice Hansen, of the Planetary Science Institute and co-author of the paper, said: "There are a variety of different types of features on Mars that sometimes get lumped together as 'gullies,' but they are formed by different processes.
"Just because this dry-ice hypothesis looks like a good explanation for one type doesn't mean it applies to others."