Powerful sun storm knocks out radio transmissions across North America

A powerful solar flare disrupted radio and navigation signals across North America on Monday (Aug. 7) and prompted space weather forecasters to issue warnings because of energetic particles hitting Earth.

The flare, classified as an X1.5, was the 20th X flare — the most potent solar flare category — of the current 11-year solar cycle, which will reach its maximum next year.

Solar flares are energetic flashes of radiation that explode from magnetically dense, cool regions on the sun's surface known as sunspots. Traveling at the speed of light, the photons from these flares arrive at our planet in eight minutes. As the radiation from the flares interacts with particles in Earth's ionosphere, the region of the atmosphere at altitudes between 50 and 400 miles (80 and 650 kilometers), it supercharges them. These changes then affect radio and satellite signals that pass through this region.