(Gizmodo) Concentric rings of highly charged radiation encircle our planet, and we know surprisingly little about them. But once NASA completes a $686 million mission to launch a twin pair of space probes into the eye of this solar storm, the Van Allen belts should be much less of a mystery.
The Van Allen belts were discovered in 1958 by University of Iowa professor James A. Van Allen. The belts are two layers of the same doughnut of charged plasma—the inner belt stretches from the edge of the atmosphere to a radius of 4,000 miles, and the outer belt stretches from 8,000 miles to roughly 24,000. Thy're held in place by our planet's magnetic field. Nearly all of humanity's communications satellites orbit at the outer edge of the 4,000-mile gap that separates the two belts.