SOLAR FLARES: Today, Jan. 19th at 1340 UT, Earth-orbiting satellites detected the strongest solar flare in almost two years. The M2-class eruption came from old sunspot 1039, currently located behind the sun''s eastern limb. NASA''s STEREO-B spacecraft recorded this extreme ultraviolet movie of the blast:

Click here to view the full-sized animation with labels

Considering the fact that the sunspot is not even visible from Earth, the flare was probably much stronger than its M2 classification would suggest. This active region has produced at least three significant eruptions since Jan. 17th (including this notable flare) and it is showing no signs of cooling off.

At the moment only STEREO-B, stationed over the east limb, can monitor the active region directly. Soon, this will change. The sun''s rotation is turning sunspot 1039 toward Earth and it should emerge for direct viewing within the next 48 hours. Readers with solar telescopes are encouraged to monitor the east limb for developments.