Moon and Saturn
Hailstorms rumble from the Great Plains to the Atlantic seaboard at this time of year. They pummel the ground with chunks of ice that range in size from BBs to baseballs -- and sometimes bigger.
If you scoop up a handful of hailstones, you can get a feel for the rings of Saturn. Much of their material also consists of chunks of ice -- most of which are about the same size as hailstones.
Saturn has thousands of rings. Many of them group together to form three broad bands. These bands make up the bright rings that are visible through telescopes. Several smaller, thinner rings extend beyond the bright ones.
Some of the rings consist mainly of ice -- "hailstones" frozen as hard as granite. Others consist mainly of bits of rock and dust. And still others are a mix of the two.
This varied composition suggests that the rings formed when a small moon passed too close to Saturn, and was torn apart by the planet's gravity. The debris spread out along a wide path, with material of the same composition clumping together at the same distance out from the planet.
Just when this happened is unclear, though. Scientists used to think that it took place fairly recently. But recent observations suggest that it happened much earlier -- making Saturn's rings not just beautiful, but ancient.
Saturn looks like a bright star to the lower left of the Moon as darkness falls tonight. A small telescope will reveal the planet's glorious rings.
Script by Damond Benningfield, Copyright 2010
For more skywatching tips, astronomy news, and much more, read StarDate magazine.