NASA scientists have confirmed a vast amount of ice at the north pole — on Mercury, the closest planet to the sun.
The findings are from NASA's Mercury-orbiting probe, Messenger, and the subject of three scientific papers released Thursday by the journal Science.
The frozen water is located in regions of Mercury's north pole that always are in shadows, essentially impact craters. It's believed the south pole harbors ice as well, though there are no hard data to support it. Messenger orbits much closer to the north pole than the south.
"If you add it all up, you have on the order of 100 billion to 1 trillion metric tons of ice," said David Lawrence of the Applied Physics Laboratory at Johns Hopkins University. "The uncertainty on that number is just how deep it goes."