What do you see here? Just some sand?
This could easily be a close-up photo of a tiny patch of beach. Or it could just be a macro image of the grains in a child's sandbox, with bucket and spade just out of shot. But it's neither. Sure, it's sand, but it's Martian sand. Think about that for a moment: We're looking at a microscopic observation of the grains of sand on another planet.
NASA's Mars rover Curiosity, which has been exploring Mars since 2012, is currently driving up a mountain on Mars in the middle of the vast Gale Crater, seeking out evidence of past (and present) habitable environments on the Red Planet. And along the way, the awesome six-wheeled robot has encountered dark sand dunes, so mission scientists decided the rover should check out the 2-storey-high "Bagnold Dunes.
Taken on Sol 1184 of the mission (Dec. 5), this image shows a close-up of the dunes' sand grains, taken by Curiosity's Mars Hand Lens Imager (MAHLI) camera. Observations such as these help scientists understand mineral composition of sand on Mars, and how the dunes, particularly active ones like the Bagnold Dunes, evolve.