A new group of spots traversing the face of the sun could unleash a major flare, though that probability is low, according to the U.S. Space Weather Prediction Center in Boulder, Colo.
But the group, dubbed sunspot group 1045, is an active region that already has produced moderate solar flares.
Sunspots are areas of intense magnetic activity, cooler than the surrounding solar surface. They act like caps on a soda bottle, and when things are shaken up sufficiently, the caps blow and a flare of radiation is released, often along with a cloud of charged particles called a coronal mass ejection.
Such space weather can pound Earth’s protective magnetic field, with the most severe storms crippling satellites and having the potential to knock out power grids on Earth.
Each of the new spots in the group is about twice the diameter of Earth, according to Spaceweather.com.
The sun has been relatively quiet the past two years. It is at the low point in a known 11-year cycle of activity. The next peak of activity, known as solar maximum, is expected sometime in 2013.