Sun Gets in the Loop

April 21, 2010

A huge loop of material shooting up from the sun's surface in March was one of the first events witnessed by NASA's Solar Dynamics Observatory. Known as a prominence eruption, the loop was born from a relatively cold cloud of plasma, or charged gas, tenuously tethered to the sun's surface by magnetic forces. Such clouds can erupt dramatically when they break free of the sun's unstable hold.

"We are all living in the outer atmosphere of a star. Its variability influences Earth, the other planets, and the whole solar system," Richard Fisher, NASA's director of heliophysics, said today at a press conference. For example, strong solar eruptions called coronal mass ejections can send bursts of charged particles streaming toward Earth, where they can overload our planet's magnetic shield, knocking out satellite communications and power grids. the rest/image