Spectacular photos show the northern lights around the world

A series of powerful solar storms colored skies across the Northern Hemisphere this weekend, as people witnessed brilliant displays of the northern lights in the United States, Canada, Europe, China and beyond. Officials have said the dazzling light shows could continue for several more days.

The aurora borealis — the phenomenon more commonly known as the northern lights — happens because of a molecular collision in the upper levels of Earth's atmosphere that causes bursts of energy to be released in the form of visible light. The aurora borealis has a counterpart, the aurora australis, or southern lights, which is the same phenomenon in the southern hemisphere. These light shows can be visible for as much as half the year in certain places near either of the planet's two poles, but it's uncommon to see them in areas that are closer to the equator, which is why the spectacles over North America, Europe and other places on similar latitutdes were such a treat in the last few days.

The aurora will extend from the poles toward the equator in periods of intense space weather activity, and it has been known in the past to reach as far as the continental U.S. when the activity is particularly extreme. That was the case over the weekend, as an unusually strong geomagnetic storm reached Earth and set the stage for a string of explosive nighttime scenes world over. The geomagnetic storm that arrived on Friday was a historic G5, the highest level on a ranking scale that starts at G1, according to the National Oceanic and Atmospheric Administration.