GREENBELT, Md., May 15 (UPI) -- NASA says activity on the sun is ongoing as the fourth X-class solar flare of this year erupted late Tuesday, causing temporary radio blackouts on Earth.
The latest flare, which peaked at 9:48 p.m. EDT Tuesday, was rated as an X1.2 flare, on a numerical scale in which each number is 10 times as intense, so for example an X2 is 10 times as powerful as in X1, the space agency said Wednesday.