Space weather officials say the strongest solar storm in more than six years bombarded Earth with radiation.
The radiation is mostly an issue for satellite disruptions and astronauts in space. It can cause communication problems for polar-traveling airplanes.
The Space Weather Prediction Center in Colorado observed the flare on Sunday at 11 pm EST. (0400 GMT). Physicist Doug Biesecker says the biggest concern is the radiation, which arrived on Earth an hour later. It will likely continue through Wednesday.
Biesecker said the storm's radiation levels are considered strong but other storms have been more severe. It is the strongest level since May 2005.