The aurora borealis is usually visible only way up north, but over the past 18 months, shimmering curtains of pink and green light have filled night skies across much of North America, at times offering dazzling displays as far south as Texas and Hawaii.
These widespread light shows have been caused by especially strong blasts of solar wind—electrically charged particles shot out from the sun at incredible speeds. The strength of these is down to the sun reaching the peak of its solar cycle, a period of increased solar storms that happens every 11 years. Although the cycle’s peak has just passed, stronger than usual storms—and unusually widespread auroras—are expected