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Sun Power

June 13, 2012

For three days in early March, Earth weathered a series of powerful storms from the Sun. They heated the outer atmosphere, causing it to puff out. They briefly knocked several satellites out of commission. And they forced airlines to reroute flights that normally fly across the north pole, where there’s less protection by Earth’s magnetic field.

The magnetic field, along with Earth’s atmosphere, prevent most of the energy and particles from hitting the surface. But the Moon and many other bodies in the solar system don’t have that protection. These moons and asteroids are airless, and they generate no magnetic field. So the outbursts of charged particles slam into their surfaces like celestial sandstorms.

Many of the particles in the solar wind become embedded in the rocks and dirt at the surfaces of these moons and asteroids. But they also help chip away those surfaces, in a process called space weathering.

Most space weathering is done by micrometeorites — small rocks that zip through the solar system. When they hit a moon or asteroid, they break up bits of its surface.

But the solar wind also contributes to space weathering. The atomic particles are moving at speeds of up to a few million miles an hour, so they can chip off tiny bits of material and redeposit them elsewhere on the surface, or send them fluttering off into space. Solar storms accelerate that process — “weathering” the surfaces of the solar system’s airless worlds.


Script by Damond Benningfield, Copyright 2012


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