Ice- Sleds On Martian Dunes
Let’s go sledding! Well we may not be able to go sledding, but NASA has found evidence of ice-sleds on Mars. The unique features were found by the Mars Reconnaissance Orbiter (MRO).
After studying images and conducting their own tests on sand dunes in Utah and California, NASA has concluded that these deep groves seen in MRO images are probably from frozen carbon dioxide — dry ice sleds, gliding down the dunes on Mars.
The grooves are called linear gullies. They are typically seen with a relatively constant width of a few yards or meters across. They have levees along the sides, much like you’ve seen when you carve a line in the sand at the beach with a stick. But unlike gullies that are made by water, the bottom portion of these gullies are not filled with debris carried down the hill by the water. The Martian ice-gullies simply have pits at the end of their line, perhaps where the ice sled ended up and melted away.
Read more about the Martian Ice-Sleds at NASA’s Jet Propulsion Laboratory – California Institute of Technology: Marks on Martian Dunes May Be Tracks of Dry-Ice Sleds.