The Night Sky in January 2016: Phobos, the larger of the two Martian moons, is on a path to destruction
Phobos. It means fear. With a seven-mile diameter, it is the innermost and biggest moon of Mars. Our impressive Nasa picture shows a world so small that a jumping astronaut would be propelled into space.
Phobos is doomed. Its orbit round Mars is decaying, bringing it closer to its parent world by an inch every year. It will eventually disintegrate from tidal pressure and become a ring of debris like that of Saturn.