Lunar ice rink? Earth science.

Scientists used to say the Moon was bone dry -- a virtual desert in the sky. Now they think they've discovered water on the lunar surface!

It's not ready-to-drink liquid water, says Paul D. Spudis, a geologist at the Lunar and Planetary Institute in Houston. "We think we have found ice," he says, and lots of it -- mixed with rocks and dirt in a 7,700-square-kilometer (3,000-square-mile) area at the Moon's South Pole. That's an area about twice the size of Rhode Island.

If Spudis is right, he and other scientists envision future space travelers stopping off at a lunar "filling station." They could melt ice to drink and could also refuel their rockets. (The hydrogen and oxygen in water are also components of rocket fuel.)

Spudis helped make the discovery while analyzing radar signals sent back by Clementine, a small spacecraft that orbited the Moon in 1994. The signals, which reflected toward Earth after bouncing off the Moon, indicate which areas are rocky and which areas may be icy, Spudis explains.

The scientists think the ice came from comets that have collided with the Moon over the last 3 billion years. Comets are about 90 percent frozen water, Spudis explains.

To check if this wet-and-wild discovery is true, NASA win launch another Moon-orbiting spacecraft, the Lunar Prospector, in September. "We have a long way to go before people live on the Moon," Spudis says. But this discovery "is an indication that it might be possible." Maybe one day you'll be licking Moonpops and skiing down icy lunar slopes.