(Iowa & the Midwest) – Skywatchers who were away from city lights saw some awe-inspiring sights Friday night into early Saturday morning, as mostly clear skies allowed the Aurora Borealis/Northern Lights to make a stunning appearance. The images flooded social media. The event occurred due to a geomagnetic storm –  called a coronal mass ejection, or CME – that was rated as level G5. This is the first G5-level storm since October 2003. The light show is expected to diminish late Sunday.

The source of the solar storm is a cluster of sunspots on the sun’s surface that is 17 times the diameter of the earth. The spots are filled with tangled magnetic fields that can act as slingshots, throwing huge quantities of charged particles towards our planet. Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting communications, the electric power grid, navigation, radio and satellite operations.

Unlike solar flares, which travel at the speed of light and reach Earth in around eight minutes, CMEs travel at a relatively more sedate pace, with officials putting the current average at 800km per second. Here are some of the pictures shared on the National Weather Service’s Facebook page:

St. Cloud, MN

Johnston, IA

Emmetsburg, IA

Brooklyn, IA

Boone County, IA

Greenfield, IA

Newton, IA