Yesterday morning, the sun unleashed a powerful X1 solar flare. X-flares are the most powerful classification of solar eruption there is. This is the latest in a string of recent outbursts, with yesterday's eruption among the most violent we've seen all year.
Above: An X1-class flare erupts from the right side of the sun, emerging from a region that has produced many flares in its two-week journey across the in this image captured by NASA's Solar Dynamics Observatory on November 19th, 2013. The flare erupted from an active region that produced many flares over the last two weeks, as it made its way across the Earthside surface of the Sun.
This flare came from an active region numbered AR 1893 that is just rotating out of sight over the sun's right side. Increased numbers of flares are quite common at the moment, since the sun's normal 11-year activity cycle is ramping up toward solar maximum conditions. Humans have tracked this solar cycle continuously since it was discovered in 1843, and it is normal for there to be many flares a day during the sun's peak activity.
The most powerful flare of 2013 came earlier this month, when an X3.3-class flare sprang to life on November 5th. (An X2-class flare is twice as powerful as an X1; an X3 thrice as powerful.) The spike in activity comes after astronomers predicted earlier this year that 2013's could be the weakest solar maximum since the dawn of the space age. But 2013 isn't over, and there could be some superstorms in store for us yet. Let's hope none of them are pointing in our direction. Yesterday's explosion also hurled a coronal mass ejection into space (see the animation at left). Fortunately, the cloud of particles it emitted was not pointed directly at Earth, and so effects planetside were limited to a brief blackout of HF radio transmissions around the poles.