Nasa's Curiosity rover has found some pretty stunning stuff on the surface of Mars in its year on the Red Planet. But some of the most amazing pictures of all have come when the rover has looked up at the sky instead. The latest incredible video shows Mars' two moons - Phobos and Diemos - flying overhead, in a timelapse clip made from 41 separate photographs taken on 1 August. "The ultimate goal is to improve orbit knowledge enough that we can improve the measurement of the tides Phobos raises on the Martian solid surface, giving knowledge of the Martian interior," Mark Lemmon of Texas A&M University said in a statement.
