There was a powerful solar flare that knocked out radio, and it could be headed for the Earth. It’s one of the largest ever recorded.

The flare is the strongest in six years, knocking out radio frequencies. It will hit Earth in several days, scientists warn.

“This is likely one of the largest solar radio events ever recorded,” NOAA wrote in a report Thursday.

Flares are caused by localized explosions on the sun’s surface that expel intense bursts of electromagnetic radiation.