Washington Post via Tweetmeme:

Between 7 and 8 p.m.Tuesday night, the sun spit out a large, X5-class solar flare. NOAA’s Space Weather Prediction Center called it “one of the largest solar flares of the current solar cycle.”

X class flares are the strongest category of solar flares. According to NASA, they can trigger planet-wide radio blackouts and long-lasting radiation storms.

These flares are often complemented by phenomena known as coronal mass ejections (CME) which are essentially bursts of solar wind. If a CME is directed toward the Earth, a geomagnetic storm results that can interfere with the Earth’s magnetosphere.

NOAA said predictions for this particular flare/CME event “are still being refined.”