Which planet in our solar system do you think would be the least likely to have frozen water? You'd think it would be Mercury, right? After all, it's barren, rocky and it's the closest planet to the sun. It has no atmosphere to protect it from the harsh radiation of our home star. But that's exactly the planet where scientists have just discovered ice.
New pictures from the MESSENGER spacecraft orbiting Mercury show compelling evidence that there is in fact ice on the surface. The bright, yellow-outlined portions show where radar reflections from the MESSENGER probe were brighter than the rest of the planet. That indicates ice.
It turns out that Mercury has some extremely deep craters at the north pole. Because of the craters' depth and the steep latitude, the sun's rays never touch the bottom of the craters. That means it's very cold there, and comet or asteroid ice that bombards the planet can survive there more or less indefinitely.
There's so much ice, in fact, that the scientists estimate there's about as much water on Mercury as there is in Lake Ontario - between 10 billion and 1 trillion tons. That's a lot!
Mercury will probably never be a good spot for a colony, even with the water there. But other research shows the Moon may have similar ice deposits which could be used to support human habitation. Cool, huh?