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 December 16 Night and Day in Melas Chasma on Mars Credit: Arizona State U., JPL, NASA Explanation: What types of terrain are found on Mars? Part of the answer comes from thermal imaging by the robot spacecraft 2001 Mars Odyssey currently orbiting Mars. The above picture is a superposition of two infrared images, a black and white image taken during Martian daylight and a false-color image taken...