Sunspot 1041 (a.k.a. "old sunspot 1039") is crackling with solar flares. Over the past few days, it has produced five M-class eruptions. Click here to play a movie of the latest, an M2-flare recorded by STEREO-B at 1756 GMT on Jan. 20th.

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© STEREO-B
The ongoing sequence of flares signals a sharp upturn in solar activity. Before this week, the last time the sun produced even a single M-class solar flare was in March 2008--almost two years ago. M-class solar flares have a moderate effect on Earth. Mainly, they boost the ionization of Earth's upper atmosphere and disturb the propagation of terrestrial radio signals.

Sunspot 1041 has just emerged over the sun's southeastern limb. Readers with solar telescopes are encouraged to monitor developments.