Like the other giant planets of the outer solar system, Neptune has a large family of moons and rings. Astronomers have logged 14 moons, and they’ve seen three skinny rings and two or three wider ones. The rings are so hard to see, though, that they weren’t confirmed until the 1980s.

The skinny rings are the most prominent. Their material is packed close together. They probably consist of tiny particles of ice. The particles may have a coating of methane that’s been turned red by radiation from the Sun and stars.

Those rings are named for three of the men involved in Neptune’s discovery. From closest to farthest, they’re known as Galle, Leverrier, and Adams.

Galle is only about 10,000 miles above Neptune’s cloud tops, with Adams about twice that far. Adams has five big clumps of material that are brighter and denser than the rest of the ring. The clumps may be held in place by the gravity of a small moon.

Several lines of evidence suggest the rings are quite young — perhaps no more than a million years old. And they appear to be changing in a hurry — sculpting their shapes as we watch.

And speaking of watching, Neptune is putting in its best appearance of the year this week. It rises at sunset and is in view all night. It’s also brightest for the year. Yet it’s so far away that you need a small telescope to see it. As night falls, it’s to the upper right of the brilliant planet Jupiter.
 

Script by Damond Benningfield

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