Moon and Saturn

StarDate: December 8, 2009


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The Cassini spacecraft has been orbiting Saturn for half a decade. Even after all that time, though, it's still making discoveries. It recently found bumps and walls in the planet's rings that are miles high, for example. And a storm it's been watching on Saturn itself set a record: the longest-lasting lightning storm ever seen on any planet.

Cassini got a better view of the structures in the rings because the rings turned edge-on to the Sun. Structures in the rings cast long shadows that were easily visible to Cassini's camera.

The main rings span about 170,000 miles, but for the most part, they're only about 10 yards thick. But Cassini found big clumps of rock and dust more than two miles high. It also found a "wall" of ice particles built by the gravity of one of Saturn's small moons. It, too, was about two miles high.

The storm is in a zone in Saturn's southern hemisphere that appears to be the equivalent of Tornado Alley here on Earth -- it's always stormy. But this storm is the champ. It began in January, and by September it had been whirling for eight months, smashing a record set by another Saturn storm a year earlier -- just one more discovery for a mission that's made plenty of them.

Saturn teams up with the Moon the next couple of nights. Saturn looks like a bright golden star. It's to the lower left of the Moon as it rises in the wee hours of tomorrow morning, and due left of the Moon at first light.

Script by Damond Benningfield, Copyright 2009


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