A solar flare is a sudden burst of light on the sun’s surface, usually accompanied by a giant release of radiation into space. At 7:49 p.m. EST on Feb. 24, 2014, what scientists call a significant solar flare peaked.
How significant is significant? The classification scale runs A, B, C, M and X, with X being the most intense. The scale is further divided into X1, X2, etc. The numbers give information about the strength of the flare: an X2 flare is twice as intense as an X1; an X3 is three times as intense. This flare is an X4.9-class flare.
The radiation released by flare can’t pass through Earth’s atmosphere to reach the surface (and human life), but it can penetrate the atmosphere far enough to disturb GPS and communications signals.
Here’s a coronagraph view of the coronal mass ejection that accompanied the flare:
NASA’s Solar Dynamics Observatory captured the event and produced the images seen here. Read more at: NASAs SDO Shows Images of Significant Solar Flare.