PHOTOS: Kaleidoscope in the sky as northern lights appear
May 18—The northern lights became visible across the globe in areas where they rarely are seen beginning May 10 and ending today.
The lights were caused by an unusually strong solar storm from the sun which caused the National Oceanic and Atmospheric Administration to issue a geomagnetic storm watch for the first time in nearly 20 years, according to NOAA's Space Weather Prediction Center. The sun is nearing peak activity in its 11-year cycle, known as solar maximum, leading researchers to observe increasingly intense solar flares. The current cycle began in 2019.
The solar flares continued into the last week, with NASA detecting the strongest flare of the current cycle Tuesday in a X8.7-class eruption. In contrast, the flare that caused dazzling colors across the May 10 sky was a X2.2 flare.
The solar flares are powerful bursts of electromagnetic radiation caused by magnetic disturbances on the sun. According to livescience.com, they occur when magnetic field lines in the sun's atmosphere tangle and snap, releasing excess energy.
The solar storms are not dangerous to humans, thanks to Earth's magnetic field and thick atmosphere. However, they can affect electronics. NASA said the weekend geometric storm caused its environmental satellites to rotate unexpectedly and go into protective hibernation known as safe mode. Astronauts at the International Space Station were advised to stay in areas with strong radiation shielding. The crew was never in any danger, NASA said.
