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.
(Read "Magnetic-Shield Cracks Found; Big Solar Storms Expected.")
Since launching the Solar Dynamics Observatory, or SDO, in February, mission managers have been powering up and calibrating the craft. Today NASA unveiled the first pictures and video taken by the SDO's suite of instruments, which were designed to show the full range of the sun's magnetic activity in unprecedented detail.
Although the Solar Dynamics Observatory isn't the only solar probe in orbit, it is "the most advanced spacecraft ever built to study the sun," said NASA spokesperson Dwayne Brown. Billed as the Hubble of heliophysics, the SDO "will change textbooks," Brown predicts.