Solar flares are ten million times more powerful than a volcanic explosion on earth. They increase in frequency during the solar maximum phase of the sun's 11-year cycle. This cycle is expected to peak in 2013.
At about 7pm Eastern Time on Tuesday, the surface of the sun was rocked by a massive explosion, ten million times more powerful than a volcanic explosion on Earth. And about an hour later, it exploded again.
Now, two waves of charged plasma are streaming toward our planet at about four million miles per hour, threatening to knock out satellites and induce unwanted currents on power grids around the globe.
X-class flares, the highest classification of solar eruptions, and their attendant ejections of charged particles, are nothing new these days. On Valentine's Day 2011, the sun produced its first X-class flare since 2007. Then, in August, the sun blew up again with the largest flare since 2006.
What's with all the recent activity? Is the sun going crazy?
The current increase in the number of X-class flares is actually part of a normal cycle. Cycles can be as short as nine years and as long as 14, but they last 11 years on average. Scientists speculate that the timing of solar cycles may be associated with the reversal of the sun's magnetic poles every 10 to 12 years. Just like the Earth, the sun has north and south poles that periodically reverse themselves. The sun's current cycle is expected to peak in late 2013.
During the maximum portion of the sun's cycle, there can be several hundred sunspots, that is, dark areas on the surface of the sun that indicate intense magnetic activity, in a single day. Some of those areas erupt into flares, and, if they are on the side of the sun facing our planet, they can end up sending a cloud of plasma our way.