[Credit: HiRISE, MRO, LPL (U. Arizona), NASA]
Carbon dioxide!?!?
Oh No!!!
Soon Mars will be as hot as Venus!!!
If a big chunk of solid CO2 were sublimating, its size would be constantly decreasing and you wouldn’t get constant-width tracks. The track widths stay constant right to the very end where the tracks stop. I don’t think the sublimating CO2 theory fits.
A few days ago someone posted a video of researchers on Earth doing this down some sand dunes. It’s pretty “cool.”