A close up of the sun in extreme ultraviolet light taken by STEREO's Extreme Ultraviolet Imager (EUVI). Featured are magnetic loops filled with million-degree Celsius material.

The STEREO (Ahead) spacecraft observed this visually stunning prominence eruption on Sept. 29, 2008 in the 304 wavelength of extreme UV light. It rose up and cascaded to the right over several hours, appearing something like a flag unfurling, as it broke

Coronal mass ejection as viewed by the Solar Dynamics Observatory on June 7, 2011

This image depicts coronal rain. Encircled are two plasma streamers, one hitting the sun's surface and another incoming behind it.

NASA's Solar Dynamics Observatory captured this view of a powerful M3.6 Class solar flare on Feb. 24, 2011 during a 90-minute sun storm. NASA scientists called the display a "monster prominence" that kicked up a huge plasma wave.

A full-disk multiwavelength extreme ultraviolet image of the sun taken by SDO on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter.

SDO observed as an active region emerged, expanded and blew out at least four flares over about a 40-hour period (June 11-12, 2010). These flares were about average in terms of their power.

The Sun.