Saturn II

As far as anyone knows, Galileo Galilei was the first person to look at Saturn through a telescope. And the sight was astounding. He saw what looked like “bumps” on either side of the planet. He thought they were giant moons.

A half-century later, in 1659, Christiaan Huygens looked at the planet with a better telescope. He saw some space between Saturn and the bumps. He suggested that the bumps weren’t moons, but instead were formed by a wide, flat ring around the planet.

We’ve been learning about the rings ever since. Better telescopes allowed astronomers to see them in more detail. And spacecraft have provided even more detail.

The first new detail was seen by Jean-Dominique Cassini, who discovered a dark gap in the ring. That indicated that there’s more than one ring. In fact, thanks to visits by spacecraft, today we know that there are thousands of them. Some are braided, and some form “ringlets” instead of complete rings.

The rings are held in place by the gravity of small moons orbiting within the rings. And the rings consist mainly of small bits of ice, with some rock and dust mixed in — beautiful features for a well-studied planet.

And Saturn is well placed for more studies. It’s lining up opposite the Sun, so it’s in view all night. It’s brightest for the year, too. It looks like a bright star low in the southeast at nightfall, and crawling across the south during the night.

More about Saturn tomorrow.

Script by Damond Benningfield