( CNN ) -- The sun is putting on a fireworks show again . NASA cameras captured images of what the agency is calling at least two `` significant '' solar flares . The first one peaked at 7:42 a.m . ET Tuesday , followed by a second , lesser blast at 8:52 a.m . ET . The short-lived explosions were expected to disrupt high-frequency radio communications on Earth , although NASA scientists said they pose no threat to humans . Even with all its power , the sun does n't have enough energy to hurl a fireball 93 million miles at the Earth . Solar flares are powerful bursts of radiation that send gases , plasma and other matter into the solar system . Harmful radiation from a flare can not pass through Earth 's atmosphere to affect humans , but when intense enough , the explosions can disturb GPS and communications signals , NASA said . The first flare was classified as an X2.2 flare , which is unusually bright . Scientists classify solar flares by size , in much the same way they do tornadoes or earthquakes : X-class flares are the biggest and are major events that can trigger planetwide radio blackouts ; M-class flares are medium-size ones ; and C-class flares are small , with few noticeable consequences here on Earth . The number after the letter provides more information about a flare 's strength . An X2 is twice as intense as an X1 , an X3 is three times as intense , and so on . A huge flare can be many times larger than the Earth . The second flare Tuesday was classified as an X1.5 flare . The images were captured by NASA 's Solar Dynamics Observatory , which typically observes the entire sun 24 hours a day . Solar flares are not uncommon , as such activity has been increasing in recent years . NASA has recorded a handful of large- and medium-size flares already in 2014 , although few were as bright as the first one Tuesday morning . To see more about how the flares may affect Earth , visit the National Oceanic and Atmospheric Administration 's Space Weather Prediction Center , the U.S. government 's official source for space weather forecasts and alerts .
NASA releases images of `` significant '' solar flares Tuesday . The sun is currently in a period called Solar Cycle 24, which began about 10,000 years ago and will end around 2040. The explosions might disrupt high-frequency radio communications on Earth .