Something is happening to the sun. One of the regions of the solar atmosphere currently exhibiting sunspots caught the attention of observatories on July 11, when there was a sudden increase in ultraviolet and X-ray brightness. The next ones to notice were the amateur radio communities on either side of the Pacific Ocean, when their communications were briefly interrupted.
A solar flare—the emission of electromagnetic radiation and energetic particles located in a small region of the solar atmosphere—had just occurred. It is a region where the magnetic field is particularly strong and complex.
A solar flare often precedes a much more powerful event. The same magnetic field that generated the flare twists beneath the sun’s surface, drags huge amounts of solar plasma out of the sun and, like a cannon, hurls it at high speed into space. This is called a coronal mass ejection….