Throughout 2012, the sun has been in an active part of its 11-year cycle of activity. Dark spots have been seen at sun's surface. Space observatories have been detecting short-lived but brilliant and powerful solar flares - intense bursts of radiation and our solar system's largest explosive events.
Occasional, powerful coronal mass ejections - giant bubbles of gas and magnetic fields from the sun, containing up to a billion tons of charged particles that can travel up to several million miles per hour - have been released into the interplanetary medium. This solar material has streamed out through space, and sometimes has struck Earth. Is this dangerous? Should we be worried?