What's carving active gullies on Mars? It's not water
Scientists were shocked when they received the first images of Martian gullies. They were even more shocked as those gullies appeared to change over time. Their similarities to gullies seen on Earth were uncanny, but all of Earth's gullies are formed by water runoff, and Mars is too cold and has too sparse an atmosphere to have liquid water on its surface. Whatever has been causing those changing…
We haven't written up this one. Phys.org has the full story — the link below goes straight to it.
