In a photo released by NASA on February 28, an enormous solar prominence erupts from the surface of the sun, blasting particles and a shock wave toward Earth. (Related: "Solar "Tsunami:" Giant Double Sun Eruption Caught on Video.")
Scientists think the wave of material was responsible for the formation of a radiation belt encircling the Earth that no one had ever seen before.
Normally, the Earth is surrounded by two doughnut-shaped radiation belts known as the Van Allen belts. Researchers have known about them since the 1950s. With the launch of the Van Allen probes in August 2012, astronomers hoped to get a better picture of these two areas of radiation.
What they found was a third region of radiation that they think the August 31, 2012, eruption—pictured above—produced. This new belt only lasted for four weeks before another shock wave emitted by the sun destroyed it. (See more pictures of solar activity and space weather.)
—Jane J. Lee