Photos Show Incredible Northern Lights Sparked by Solar Storm

Earth experienced a geomagnetic storm over the weekend, causing auroras that wowed people across Scandinavia and as far south as the U.K.

Geomagnetic storms are the result of charged particles that arrive at Earth after being ejected from the sun at such high speeds that they can take just a couple of days to get here.

These particles can interfere with Earth's natural magnetic field, causing the auroras that many will be familiar with. They are known as the northern lights in the northern hemisphere and the southern lights in the southern hemisphere.

On Sunday a moderate-strength geomagnetic storm occurred and several people took to Twitter to post photos of the northern lights that resulted.

"A little bit of magic to end the week," wrote one person who took photos of the auroras from Scotland.

Typically, auroras are only seen around the polar regions. In other words, you are more likely to see the northern lights the further north you go. During geomagnetic storms, however, auroras can travel closer to the equator.

The weekend's geomagnetic storm occurred on Sunday. It was described as a G2-level storm by the U.S. National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC), which warned that it could cause effects like power grid fluctuations, HF radio interference at high latitudes, and increased drag on satellites operating in low-Earth orbit.

The storm was caused by a coronal mass ejection (CME) from the sun that had occurred a few days before. CMEs are large explosions of electrically charged gas from the sun that can travel at millions of miles per hour.

They occur due to tense magnetic field structures in the sun. Sometimes these magnetic fields suddenly realign themselves, releasing huge amounts of energy in the process.

Measuring Severity of Solar Storms

Some solar storms are stronger than others. The G scale, which measures geomagnetic storm strength, goes from the most minor G1 storms to the most extreme G5 storms. G5 storms can cause complete collapse of power grid systems, problems communicating with satellites, radio outages for days, and auroras as far south as Florida and southern Texas in the U.S.

According to the SWPC on Sunday, geomagnetic storms may continue through to Tuesday, by which time they will have weakened to G1.

The sun goes through periods of increasing and decreasing energy known as the solar cycle. Each cycle lasts around 11 years. The last one reached its low point in 2020, so the sun is currently going through a period of increasing energy. This period is predicted to peak some time around 2025 before lessening once again, SWPC data shows.

Northern lights
A file photo depicts the northern lights over a wooded area in Alaska. The northern and southern lights are caused by energy from the sun. Elizabeth M. Ruggiero/Getty