The explosive sun we all know and love is back! And it’s packing a punch.
Late on Monday night, when we were all distracted by the Stardust-NExT flyby of comet Tempel 1, the sun unleashed the biggest flare for over four years. The flare, seen above through the high-definition eyes of NASA’s Solar Dynamics Observatory (SDO), is classified as one of the most powerful flares the sun can muster.
Known as an X-class flare, this particular one is ranked as an X2 on the solar flare “Richter scale”.
The last time we saw an X-class flare was on Dec. 5, 2006, when the sun produced an X9 explosion — a flare eight-times more powerful than this X2 flare.
The flare triggered a coronal mass ejection (CME), sending a cloud of energetic particles toward Earth. A series of CMEs are expected to impact our atmosphere over the next 48 hours, all emanating from the flare site — sunspot 1158.
The NOAA is forecasting a high probability of geomagnetic activity on Feb. 17th-18th. This means that for observers at high latitudes, there might be some impressive auroral activity.
Of course, it’s not just about pretty lights, space weather prediction is becoming a critical tool for our civilization to grasp. As we become increasingly dependent on sensitive communication technologies and delicate power grids, what ever happens on the sun can have serious consequences for us on the ground. (Let’s not forget what happened to the “Zombiesat.”)
Although CMEs are often featured as the main threat to us, the flare events themselves can have some serious impacts to our way of life. When the X2 flare erupted, a sudden increase in X-ray radiation was detected in Earth orbit.
According to the China Meteorological Administration (CMA), this X2 flare event impacted shortwave radio communications in southern China. As shortwave radio uses the Earth’s ionosphere (a charged layer of the Earth’s upper atmosphere) to bounce radio waves off, the condition of the ionosphere is critical. This most recent flare caused sudden ionospheric disturbances, interrupting shortwave communications over the region.
I think we can safely say the sun is awake, giving us a taste for what Solar Cycle 24 — which peaks around 2013 — has in store for us.
Image credit: NASA/SDO