Mars Express was launched by the European Space Agency in 2003, and is ESA’s first Mars mission. In one shot, you can see Mars as a half-lit disk, with Phobos, its tiny moon, hovering above. Right below Phobos is Olympus Mons, the solar system's largest volcano, towering 22 km high and 600 km across—or as the Bad Astronomer says, “about the size of Colorado”.
Posted by Andrea Luck, by way of Bad Astronomy.
