Space Radiation Probes Make 'Shock' Discovery

For more than four weeks last year, a previously unknown third radiation belt circled Earth before it was annihilated -- along with the entire outer belt -- by a shock wave from the sun.

February 28, 2013
2:00 PM EST
Artist's conception of the Van Allen Probes' orbit through the two distinct radiation belts surrounding Earth. | Johns Hopkins University Applied Physics Laboratory