Moon and Jupiter

StarDate: April 18, 2009

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Floating through the skies of the planet Jupiter would be an awe-inspiring experience. Lightning flashes through storm systems as big as states. Clouds tinted in shades of red and tan and brown descend dozens of miles into the atmosphere. And at night, a menagerie of exotic moons scoots across the dark sky.

There's just one little problem, though. To get to Jupiter you'd have to cross the planet's radiation belts. And without strong shielding, the crossing would kill you in a flash.

As Jupiter rotates, it generates a powerful magnetic field. The field traps energetic particles from the Sun, creating radiation belts.

The belts are also fed by volcanoes on Io, one of Jupiter's biggest moons. The volcanoes blast gas and solid particles into Io's atmosphere. Some of this material escapes the moon and goes into orbit around Jupiter, forming a doughnut-shaped cloud around the planet. Jupiter's magnetic field strips electrons away from the atoms in this cloud, giving them an electric charge -- and making Jupiter's radiation belts even stronger.

At Io's distance from Jupiter, in fact, the belts are so strong that an unprotected human would receive a lethal dose in just a few minutes -- not a good way to begin a tour of Jupiter's wonders.

Look for Jupiter snuggling up to our own Moon early tomorrow. They're in the east-southeast at first light. Jupiter looks like a brilliant star quite close to the lower left of the Moon.

Script by Damond Benningfield, Copyright 2009

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