When lightning makes your favorite AM radio station crackle and pop, it is also cleaning up a radiation hazard overhead.
NASA scientists have finally worked out why there's a safe zone in the Earth's radiation belts, thousands of km above the surface. It turns out that lightning in the lower atmosphere generates radio waves which interact with radiation around the Earth, removing some of its energy and changing the direction of charged particles. This safe zone could be used as a haven by satellites to reduce the damage they take while operating in these regions.
http://www.nasa.gov/vision/universe/solarsystem/image_lightning.html