Winds and Streaks of Arabia
Western Arabia Terra is a sprawling, ancient landscape on Mars rich in craters, impact debris, and features shaped by the effects of wind on rock, sand, silt, and dust.
The nameless crater seen here spans 85 kilometers (53 miles). It lies about 350 km (220 mi) northwest of the spot on Meridiani Planum where NASA landed the rover Opportunity in January 2004. But unlike that broad flatland, this scene is a lot rougher. It has more in common with another scene lying a thousand kilometers to the east.
Planetary scientists note that while many asteroids are likely solid bodies, some appear to be only loosely cohesive - flying rubble piles, in other words. If one such slammed into Mars ages ago, the outcome might look like this: a large central crater flanked by two smaller ones, all formed at the same instant.