On Wednesday morning, unusually active sunspot cluster roughly five times the size of Earth’s surface blasted out a massive solar flare — the largest one astronomers had seen in ten years. It was so big, says Bill Murtagh, program coordinator at the Space Weather Prediction Center, that it will almost certainly impact communications surrounding Hurricane Irma.

“When we get flares of this magnitude, there’s no question that high frequency communications will be affected,” he said in an interview with Inverse.

Solar flares are the largest kind of explosion in the solar system and are caused by stress that results from the reversal of the sun’s magnetic polarity. When this happens, billions of tons of magnetic plasma can be shot off into space.

The kind of massive emission that resulted from this particular flare is expected to have caused issues with radio frequencies on Earth, resulting in minute- to hour-long outages of GPS systems and high-frequency communications used by aircrafts in remote areas. Fortunately, in the case of aircrafts, back-up systems are used to ensure safety.

“It’s unfortunate timing because of this hurricane,” Murtagh said. “The sunspot cluster is complex enough where additional flare activity is possible. That could impact communication systems that emergency responders will be relying on.”

Rogue sunspot clusters like these are not uncommon in the later stages of the cycle, which we are currently in. The last flare this size occurred in 2006. The solar flare observed on Wednesday morning is the largest flare of this current 11-year sun cycle, placed in the highest class of solar flares measured.