Dune bones

A piece of Mars: The thin stripes within stripes are the bones of dunes. You’re seeing old dunes that have had their tops eroded away so you’re seeing into their insides, as if you were dissecting them in a biology class and looking at their skeletons. That’s unusual — on Earth dunes usually get buried or destroyed, so being able to see their interior structure is quite amazing. (HiRISE ESP_026992_2025)