Solar cycle 24 just got started a few days back. The sun announced it with a major solar flare (Big Flare Portends Beginning of Solar Cycle 24).
Solar flares rise and fall on an 11-year cycle, and last year marked what scientists thought was the solar minimum. But through the beginning of 2009, the sun stayed unusually quiet. That changed yesterday, when a major sunspot appeared on the backside of the sun, where it was captured by NASA’s STEREO instrument.
“This is the biggest event we’ve seen in a year or so,” said Michael Kaiser, research scientist with the heliophysics division at NASA Goddard Space Flight Center. “Does this mean we’re finished with the minimum or not? It’s hard to say. This could be it. It’s got us all excited.”