An unusually bright aurora borealis was visible throughout much of Alberta late Monday night and into Tuesday morning.
From Fort McMurray to Lethbridge, stargazers were treated to a show of bright green light dancing across the sky. Some on social media reported seeing the lights from as far away as the midwestern United States and the United Kingdom.
The display was courtesy of a moderate geomagnetic storm, according to the U.S. National Oceanic and Atmospheric Administration. Geomagnetic storms are changes in the Earth’s magnetic field caused by solar flares.
The light display happens when particles from the sun are carried toward the planet’s ionosphere, and those particles collide with gas particles — releasing energy that’s visible as light.
Auroras are usually seen only in polar regions, but a particularly large burst of solar energy — or coronal ejection — caused Monday’s aurora to be seen much farther south than usual.
Luckily for those who missed it, plenty of sky watchers captured photos of the display.