The Martian moons Phobos and Deimos
Phobos and Deimos raw (left panel) and processed images (right panel).
ESA's Mars Express orbiter imaged the Martian moons Phobos and Deimos together on 5 November 2009. The images were acquired with the Super Resolution Channel (SRC) of the High Resolution Stereo Camera (HRSC). The camera took 130 images of the moons on 5 November at 9:14 CET in a span of 1.5 minutes at intervals of 1s, speeding up to 0.5-s intervals toward the end. The image resolution is 110 metres per pixel for Phobos and 240 metres per pixel for Deimos - Deimos was more than twice as far from the camera.
Phobos, the larger of the two moons, orbits closer to the Red Planet, circling it every 7 hours and 39 minutes. It travels faster relative to Mars than the Moon relative to Earth. It was