The sun emitted a significant solar flare that peaked at 12:14 a.m. EST on Nov. 10, 2013.   Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. 

    To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings. 

    This flare is classified as an X1.1 class flare. "X-class" denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc. 

For a little more insight into the project see this： 

    http://www.nasa.gov/content/goddard/2013-Veterans-day-solar-flare/