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Moon and Saturn

February 20, 2014

Saturn’s rings are one of the most beautiful sights in the solar system — and one of the most perplexing. Scientists have had a hard time deciding just how and when the rings formed.

An early idea said they formed with the planet itself, more than four billion years ago. But later models showed that the rings couldn’t last that long. The models suggested that the rings formed perhaps a hundred million years ago, when a moon was shattered by an impact with a comet or asteroid.

One recent idea is a cross between the other two. It says that the rings are almost as old as Saturn itself, but they formed from the shattered “skins” of ancient moons.

According to this idea, Saturn was originally accompanied by several large moons. But the planet was still enveloped in the cloud of gas and dust that gave birth to both the planet and its moons. Friction with this material caused several of the moons to spiral toward Saturn. As they got close, the giant planet’s gravity shattered the moons’ icy crusts. The cores of the moons fell into Saturn, while the pulverized ice formed the rings.

This idea says today’s rings are probably a tiny remnant of Saturn’s original ring system — but they still help make Saturn one of the most beautiful sights in the solar system.

Saturn is in fine view early tomorrow. It’s to the left of the Moon at first light, and looks like a bright golden star. A telescope reveals the planet’s magnificent rings.


Script by Damond Benningfield, Copyright 2014

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