The face on Mars has been spotted again, this time in a nighttime infrared image that tells a bit more about its mysterious geological origins. The “face” is actually a three-kilometer long knob of sediments in the northern Cydonia region that is littered with similar knobs and mesas, said Arizona State University’s Philip Christensen, who led the investigation into the new thermal images from the Mars Odyssey spacecraft. But that doesn’t mean the features aren’t important.