This particular aurora event was caused, according to SpaceWeather.com, by a coronal mass ejection (CME) that occurred around 1pm CDT today [10-24-11] and hit the Earth's magnetic field. The website states that "according to analysts at the Goddard Space Weather Lab, the impact caused a strong compression of Earth's magnetic field" and subsequent geomagnetic storm. A CME (often associated with a solar flare) is an explosion on the Sun that happens when energy is suddenly released, producing a burst of radiation. Strong flares can reach the Earth's magnetic field, like the one today. There is plenty of additional information for science "geeks" (like me!) at SpaceWeather.com and on Wikipedia (including animations and video).
It is very rare to see the Northern Lights this far south and red auroras are somewhat rare as well. The red color is not completely understood, but scientists believe that they occur much higher above the Earth than typical geomagnetic storms (300-500km) and sometimes occur during intense geomagnetic storms. [More technical details on red auroras can be found here.] The picture below was taken by Jay Malone in Corning, AR on Monday evening. Enjoy!
|Photo of Aurora Borealis over Corning, AR on 10/24/11, courtesy Jay Malone|
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