A passenger on a recent National Geographic Expedition to Antarctica took this rare photo of the vast underside of an iceberg. Alex Cornell, traveling in December with his family, was in a Zodiac boat when they neared the iceberg. "We saw thousands of icebergs, of course, but only one revealed its gorgeous underside—the 90 percent below the surface you hear so much about," he says. "Icebergs are typically white, like you see in pictures. This one had recently flipped over and had this arresting alien green color to it. It looked a lot more like a parked spacecraft than a floating iceberg."
