The two strongest solar flares of the year just erupted from the Sun — an X1.7 and an X2.8 — the first X-class solar flares of the year. A coronal mass ejection (CME) also erupted from the Sun at the same time, though it is not Earth-directed. The CME was traveling at about 1,200 miles per second when it erupted.
The X1.7 class solar flare erupted around 10 pm EDT on May 12, 2013. And the X2.8 class solar flare followed on May 13, 2013, at around 12:05 p.m. EDT. These two solar flares dwarf any other solar eruption of the year, and should be a good preview of the rest of the year, as solar activity ramps up approaching the solar maximum. The CMEs associated with these flares won’t hit the Earth though, so they shouldn’t affect electronics or satellites at all. Though it may affect NASA’s STEREO-B, Messenger, and Spitzer, spacecrafts.
The X2.8 class flare is the sixteenth X-class solar flare of the solar cycle that we currently in, and the third most powerful so far. “The second-strongest was an X5.4 event on March 7, 2012. The strongest was an X6.9 on Aug. 9, 2011.”
Some background on solar flares via NASA:
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. This disrupts the radio signals for as long as the flare is ongoing – the radio blackout associated with this flare has since subsided.
“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.
These two solar flares erupted from an active region that was almost out of sight on the far left side of the Sun, this region will soon rotate into an Earth-facing trajectory.
While these most recent solar flares and CMEs aren’t facing the Earth, and as a result won’t affect us, it’s worth remembering that when large solar eruptions are facing the Earth that they can trigger enormous and intense auroral events. In the somewhat recent past of the past two hundred years, there have been auroras reported to make the night as bright as daylight, and to be visible as far south as the Southern United States.