Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 March 22 Odyssey Over Mars Credit: THEMIS, Mars Odyssey Team, JPL, NASA Explanation: Scroll right and journey for 300 kilometers over Terra Sirenum in the cratered highlands of southern Mars. The infrared view, 32 kilometers wide, was recently recorded by the THEMIS camera on board the orbiting Mars Odyssey spacecraft. Beginning at the north (left) edge, the scene sweeps across the floor and over the rim of...