The aurora borealis is normally only visible from within 20 degrees of latitude of the North Pole. In North America, most viewing opportunities are limited to those in Alaska or the extreme northern parts of Canada. However, solar flares and geomagnetic activity can vastly increase the size of the aurora borealis, making its lights much more active and visible to much of the United States.Continue Reading
As of 2014, the farthest south the aurora borealis has ever appeared was during the solar storm of 1859, when a coronal mass ejection from the sun struck the Earth. The resulting geomagnetic storms caused electrical disruptions, often charging telegraph wires with so much energy that their operators suffered painful shocks when touching their equipment. During this particular set of storms, the aurora borealis appeared to observers as far south as Hawaii and Cuba.
The aurora borealis has a southern counterpart, the aurora australis, that occurs around the South Pole. This set of southern lights is more difficult to view because most of the region in which they occur is above the extreme Southern Ocean. Solar storms have also augmented the southern lights, however, and a particularly strong flare in 1921 made the lights visible from the island nation of Samoa near the equator.Learn more about Earth Science