These observations aim to shed light on the formation process of these unusual white pebbles high up on the crater rim.

40.5 x 30.5 cm. (15.9 x 12 in.) ...

In late October, the rover photographed a scattering of bright white rocks. The Martian pebbles present two big mysteries: What are they made of, and how did they get there? Bright white pebbles ...