In addition to two very active sunspots, this huge solar flare erupted this week.
From SOHO:
A very long solar filament that had been snaking around the Sun erupted (Dec. 6, 2010) with a flourish. STEREO (Behind) caught the action in dramatic detail in extreme ultraviolet light of Helium. It had been almost a million km long (about half a solar radius) and a prominent feature on the Sun visible over two weeks earlier before it rotated out of view. Filaments, elongated clouds of cooler gases suspended above the Sun by magnetic forces, are rather unstable and often break away from the Sun.
Good thing it wasn’t pointed right at us.
We’ll know in how many days?
Three at the most depending on the velocity of the CME matter. Since this was taken from the STEREO behind spacecraft, the Earth is at the left and some of the CME may be headed to us..