The vanished Mars Polar Lander probably broke apart in a canyon, The Denver Post reported today, citing scientists who suggested the landing site was the reason for NASA’s latest failure. The $165 million lander was supposed to touch down Dec. 3 for a 90-day mission to analyze the planet’s atmosphere and search for frozen water beneath its south pole. It has not been heard from since it started its descent after an 11-month cruise, and NASA has not offered a reason for the disappearance.