A massive solar flare flashes in the middle of the sun on Sept. 6, 2017. The image of the Earth provides scale. Credit: NASA/GSFC/SDO

On September 6, the sun let its presence be felt by unleashing two massive solar flares. The first eruption, classified as an X2.2 flare, the strongest since 2008, occurred at 5:10 a.m. ET. Shortly after, at 8:02 a.m ET, the star spewed out a bigger, and more dramatic, X9.3 flare — the strongest on record since December 2006.