A couple of days ago, NASA's solar dynamics observatory captured this spectacular video of a filament of gas arcing in the sun's magnetic fields. This image shows what the event looked like in extreme ultraviolet light — basically, a tentacle of fire whipping around and blowing up. Writes NASA:

Long filaments like this one have been known to collapse with explosive results when they hit the stellar surface below. The segment in the 304 angstroms wavelength (red Sun) covers almost 3 hours.

Radioactive particles from this eruption will probably reach Earth today, and many will be deflected by our magnetosphere.

Spotted on Wired