Powerful solar flares can cause high-frequency radio blackouts, which was potentially recorded early Sunday morning.
Powerful X-Class Solar Flare Causes Radio Blackout Over U.S.
Dangerous sunspot emerges on Sun, can BLAST powerful solar storms
NASA Captures Strong Solar Flare Explosion Causing Radio Blackout
Technology, LiveNOW from FOX
NASA spacecraft travels through solar winds to find source of
Technology
Earth may see 'minor' geomagnetic storm from recent powerful solar
Powerful Solar Flare Causes Radio Blackout Over Western US
Space Weather