PROVIDENCE, R.I. [Brown University] — With an unusually powerful geomagnetic solar storm blasting Earth in mid-May, millions of people living in the Northern Hemisphere were treated to dazzling and rare showings of the northern lights.

Also known as the aurora borealis, the lights are a natural phenomenon that occur when particles from the sun hit gases in Earth's atmosphere, resulting in brilliant hues of purple, green, red and pink dancing across the night sky. Usually, effects from the aurora can only be seen from remote regions close to the planet's northern magnetic poles, but periods of intense solar activity can cause the lights to forgo their name and be seen much further south.

Starting on Friday, May 10, the largest solar storm to hit Earth in 20 years made it possible for onlookers around the world to catch glimpses of the colorful, wavering ribbons from countries in Europe, the Mediterranean and even as far south as Florida in the U.S. In Rhode Island, things were no different, as images of the lights flooded social media and were reported in the news. Robert Horton, manager of Brown’s astronomy labs and the Ladd Observatory, was at Shippee Sawmill Pond in Foster on Saturday, May 11, from midnight to almost 3:30 a.m. observing the aurora. Below are images he captured at different points throughout the night.