Did you spot the aurora borealis (Northern Lights) in the skies on October 10th? This phenomenon is caused by the sun’s magnetic storms: solar flares and CMEs (coronal mass ejections) are two primary sources of magnetic disturbance. Generally, the aurora borealis isn’t visible as close to the Equator as Loudoun County, Virginia, and remains within the most polar latitudes of the Earth. (Fun fact: the aurora borealis has a southern-hemisphere twin! The south pole’s aurora is known as aurora australis or “the southern lights”.) However, particularly powerful magnetic storms can excite the atoms of the atmosphere in a much further radius from the poles, creating a vibrant display depending on the type and location of the atoms affected.

Couldn’t see the lights? There’s a few possibilities. First, light pollution in populated areas, such as the larger cities of Eastern Loudoun, obscures the night sky and makes stars, comets, and other natural phenomena harder to locate. If you live in an urban or suburban community, it’s less likely you were able to see the aurora. Light pollution is a major environmental problem: not only does it complicate the work of astronomers and hobbyists alike, it can cause disturbances to the patterns of nocturnally active wildlife such as owls, moths, and sea turtles. Second, your own vision might be to blame— not that it’s any fault of your own. Human eyes aren’t made for seeing in the dark, and the ‘rod’ cells we do have for low light vision don’t discern between colors like daytime ‘cone’ cells. For this reason, your cameras may be able to perceive a much more stunning color show than you see with your eyes alone.

Happy stargazing, ACL!