In less than 24 hours, the Sun has unleashed a trio of X-Class solar flares. They are the first, second and third X-class eruptions of 2013, making them the most powerful of the year by a substantial margin. What's more, each burst has been more violent than the last. So uhh... what the hell is going on here?
The outbursts began late Sunday night with a powerful X1.7-explosion, pictured below. Solar flares are classified as A, B, C, M, or X, in order of intensity, with each category 10-times stronger than the one before it. Long story short: X-class surges are biggies, and Sunday's was the first of 2013.
The flare was a surprise (it's impossible to predict when or where a solar storm will roil into existence), but its arrival was anticipated; this fall, our resident star will reach the peak of its 11-year sunspot cycle. With more sunspots comes more solar activity – and as solar activity ramps up, energetic flares like the doozy belched out on Sunday night are expected to increase in both frequency and intensity.
The next eruption came just 14 hours later – an X2.8-class flare, emanating from the same sunspot as before. This video, recorded by NASA's Solar Dynamics Observatory, compiles imagery from the first two flares:
Astronomers have since named the instigating region AR1748 [click to enlarge]:
On Sunday, AR1748 was lurking just beyond the view of NASA's Solar and Heliospheric Observatory. Since then, however, solar rotation has brought the hyperactive region into view. The above image, captured this morning, shows AR1748 just beginning to peek around the Sun's eastern limb.
The third, and most powerful, paroxysm came 9 hours and 8 minutes later – an X3.2-class burst of electromagnetic radiation from the solar atmosphere above AR1748.
Via NASA: Four images from NASA's Solar Dynamics Observatory of an X3.2-class flare from late at night on May 13, 2013. Starting in the upper left and going clockwise, the images show light in the 304-, 335-, 193- and 131-angstrom wavelengths. By looking at the sun in different wavelengths, scientists can view solar material at different temperatures, and thus learn more about what causes flares.
Remember: any one of these flares on its own would have been the strongest of the year. That we're seeing all three of them in immediate succession could be a sign that a significant increase in solar activity is at hand.
Spaceweather.com reports that the eruptions have been accompanied by coronal mass ejections (CMEs) – epic waves of charged solar particles that emanate out into space:
Coronagraphs onboard the Solar and Heliospheric Observatory are tracking the clouds [see the GIF featured above]. The planet in the CME movie is Mercury. Although the CMEs appear to hit Mercury, they do not. In fact, no planets were in the line of fire. However, the CMEs appear to be on course to hit NASA's Epoxi and Spitzer spacecraft on May 15-16.
So that's what's happening. Should you worry? Probably not – at least not for the moment (though Epoxi and Spitzer may be in for a bit of a jolt come tomorrow). Fortunately for all of us, none of the flares or CMEs have been pointed toward Earth. On one hand, when directed at our planet, X-class flares and their associated coronal mass ejections can lead to mindblowing northern lights at very non-northern latitudes (in September 1859, one of the most powerful flares ever observed produced aurorae at latitudes as low as Cuba and Hawaii); but they can also trigger massive geomagnetic storms, jam satellites, ground airplanes, and precipitate global radio blackouts.
Back in January 2012, an M2-class solar flare had experts bracing for the strongest radiation storm in over half a decade. An X-class flare in our direction, combined with a colossal, interplanetary CME, could have serious consequencees here on Earth.