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Uranus at Opposition II

October 2, 2013

As befits a giant planet, Uranus has a giant entourage of moons — at least 27. Yet the planet is so far away that its moons are tough to see. In fact, most of the moons weren’t discovered until the last three decades.

William Herschel discovered the first two in 1787 — not long after he discovered the planet itself. Herschel proposed naming them for characters from Shakespeare, and his colleagues agreed. So those first discoveries were named Titania and Oberon, for the queen of the fairies and her husband from “A Midsummer Night’s Dream.”

Not surprisingly, they’re the biggest of all the planet’s moons. Titania is a thousand miles in diameter, while Oberon is just a bit smaller.

William Lassell discovered the next two moons of Uranus — the third- and fourth-largest — in 1851. And Gerard Kuiper discovered the next one — the fifth-largest — at McDonald Observatory in 1948.

Since then, the moons have come in bunches. The Voyager 2 spacecraft revealed 10 new moons when it flew past the planet in 1986. The rest have been found since then, with Hubble Space Telescope, telescopes on the ground, and through further analysis of the Voyager observations — giving Uranus a mighty entourage.

Uranus itself is in view all night, near the border between Pisces and Cetus, and it’s brightest for the year, too. It’s so far away, though, that you need binoculars to see the planet — and a good telescope to see any of its moons.


Script by Damond Benningfield, Copyright 2013

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