The number after the letter provides more information about a flare 's strength . NASA releases warnings of ` ` significant '' solar flares Tuesday . The first occurred at 7:42 a.m . ET , with a second , lesser blast at 8:52 a.m . ET . The flare might disrupt high - frequency radio communications on Earth .
NASA releases warnings of ` ` significant '' solar flares Tuesday . The first occurred at 7:42 a.m . ET , with a second , lesser blast at 8:52 a.m . ET . The flare might disrupt high - frequency radio communications on Earth .