NASA: Probe Confirms Ice On Mercury
CAPE CANAVERAL (CBSMiami/AP) – Everyone knows there is ice at the North Pole of Earth.
Now a special messenger has just confirmed that there is also ice on the north pole of Mercury – the closest planet to the sun. The frozen water is located in regions that always are in shadows, essentially impact craters.
The findings are from NASA's Mercury-orbiting probe, Messenger, and the subject of three scientific papers released Thursday by the journal Science.
The ice is thought to be at least 1½ feet deep — and possibly as much as 65 feet deep.
"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."
There's enough polar ice at Mercury, in fact, to bury an area the size of Washington, D.C., by two to 2½ miles deep, said Lawrence, the lead author of one of the papers.
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.
For two decades, radar measurements taken from Earth have suggested the presence of ice at Mercury's poles. Now scientists know for sure thanks to Messenger, the first spacecraft to orbit Mercury.
The water almost certainly came from impacting comets, or possibly asteroids. Ice is found at the surface, as well as buried beneath a dark material, likely organic.
Messenger was launched in 2004 and went into orbit around the planet 1½ years ago. NASA hopes to continue observations well into next year.
(TM and © Copyright 2012 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2012 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)
