Huge Solar Storm Triggers Beautiful Auroras Across the Night Sky

Shimmering northern lights were sparked around the world on the night of September 26 and the early hours of September 27 after an intense burst of solar activity.

On the evening of September 26, the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC) issued a space weather notice on its website warning of a minor solar storm that could cause some effects on Earth.

Within a few hours the solar storm conditions got stronger and stronger, with SWPC eventually warning of a potential K-index of 7. The K-index is a scale used to measure the strength of solar storms by how much they interfere with Earth's magnetic field. A K-index value of 4 would be barely noticeable, while a value of 9 would be the most extreme type.

Aurora Borealis
A cropped photo of the Northern Lights seen in Reykjavíc, Iceland, posted to Twitter by astronomer Abhijeet Borkar amid strong solar activity on the night of September 26 and the early hours of September 27, 2022. Solar material can excite particles in Earth's atmosphere which is what causes the auroras. Abhijeet Borkar

By around 2:17 a.m. UTC on September 27 (10:17 p.m. ET, September 26) the SWPC said the solar activity could spark auroras in U.S. states as far south as Pennsylvania, Iowa, and Oregon.

It is unclear if auroras did occur in those locations, but several of them were spotted elsewhere.

Clear shots of the auroras were taken by astronomer Abhijeet Borkar, who took the following photos in Reykjavík, Iceland.

The below photo, posted to Twitter by photographer Derek Steen, shows red and green auroras dancing over the Russian Mountains north of the city of Chuathbaluk, Alaska, in the early hours. "They're flickering beautifully below the Big Dipper," the photographer wrote. "It never gets old!"

The following explosions of color were photographed in northern Norway by astrophotographer Adrien Mauduit, who tweeted: "There were shades of colors I had never seen!"

The sudden solar activity dwindled in strength later in the morning. As of 7:30 a.m. ET, SWPC noted that some auroral activity was still possible in the U.S. up until around 2 p.m. ET but this would be covered by daylight.

Auroras are caused when material from the sun is ejected towards Earth during periods of heightened solar activity. The energy and particles that make up this solar material interacts with Earth's magnetic field lines, which direct the solar material towards the north and south poles of our planet.

Concentrated in these regions, the particles interact with the particles in our atmosphere, causing them to give off light. Different atmospheric gases give off different colors of light. The green color of auroras signifies oxygen, while hints of purple, blue, or pink are typically associated with nitrogen.

While these interactions are usually confined to the poles, strong solar storms can cause auroras to occur much farther south than usual.

Auroras are only one effect caused by solar storms. Others include disruption to radio and satellite communication networks and power grid fluctuations. A solar storm was also responsible for the destruction of dozens of SpaceX satellites in February this year.