| Watch this and other space videos at SpaceRip.com From NASA's Scientific Visualization Studio. Solar flares may seem like far-away events, but they can damage satellites and even ground-based technologies and power grids. Every 11 years, as the sun reaches its maximum activity they become bigger and more common, and that increases the chances that one will significantly affect Earth. So what are these solar eruptions? A solar flare is basically an explosion on the surface of the sun ranging from minutes to hours in length. Large flares can release enough energy to power the entire United States for a million years. Flares happen when the powerful magnetic fields in and around the sun reconnect. They're usually associated with active regions, often seen as sunspots, where the magnetic fields are strongest. Flares are classified according to their strength. The smallest ones are B-class, followed by C, M and X, the largest. Similar to the Richter scale for earthquakes, each letter represents a ten-fold increase in energy output. So an X is 10 times an M and 100 times a C. Within each letter class, there is a finer scale from 1 to 9. C-class flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts. It's the X-class flares that are the real juggernauts. Although X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go ... |
