› View larger, › View fulldisk image
NASA’s Solar Dynamics Observatory (SDO) captured this image of an M-class flare on August 17, 2012, at 9:01 PM EDT. The flare, seen on the left (or east) side of the sun from an active region that has not yet been named, and is just rotating into view. The image is colorized in teal, which is typical for showing light in the 131 Angstrom wavelength — a wavelength particularly good for viewing solar flares. Credit: NASA/SDO
On August 17, the sun emitted a mid-level flare, peaking at 9:02 PM EDT. Solar flares are gigantic bursts of radiation that cannot pass through Earth’s atmosphere to harm humans on the ground, however when strong enough they can disrupt GPS and communications signals.
The flare is classified as an M5.6 class flare. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts.