NASA has reported a huge solar flare being emitted by the Sun, the most powerful since 2006, which has already caused some radio blackouts on Earth – and it may cause aurora visible as far south as London.
The flare was one of two emitted by the Sun yesterday morning (September 6), seen by NASA's Solar Dynamics Observatory (SDO). At 5.10am EDT, the Sun unleashed an X2.2 flare, with X-class denoting the most intense flares. Then, at 8.02am EDT, a much bigger flare measuring X9.3 was unleashed.
The last time we saw a flare this big was in 2006, which measured at X9.0. The number shows the intensity, with X2 being twice as intense as X1, X3 three times as intense, and so on.
According to NASA, the flares were emitted from an active region of the Sun known as AR 2673. This region also emitted a mid-level flare on September 4, 2017.
The timing of the flares is somewhat odd, as the Sun is currently heading towards the quieter period of its 11-year solar cycle – known as solar minimum. This cycle began in 2008, with solar minimum expected in the next couple of years.
“This is a phase when such eruptions on the Sun are increasingly rare, but history has shown that they can nonetheless be intense,” said NASA.
The Space Weather Prediction Center (SWPC) said it was expecting some radio blackouts yesterday, with high-frequency radio expected to drop out for an hour. What’s possibly more concerning, though, is that solar flares are often accompanied by a coronal mass ejection (CME).
That seems to be the case here, but we don’t yet know if the CME was pointed towards Earth. If it does come our way, it could cause a strong geomagnetic storm that will further hamper communications.
“Analysis indicates likely CME arrival late on 8 September into early 9 September,” the SWPC said.
The biggest solar flare ever recorded was a beast back in 2003, known as the Halloween Storms. That measured at X28 before overloading NASA’s solar measurement sensors, so it may well have been even more powerful.
The intensity of this latest storm means that we can expect some pretty impressive aurora. Those in Iceland and other northern regions will be assured an amazing show, but incredibly the northern lights may be visible as far south as London. You can see a prediction of the expected aurora here.
If that's confirmed (we've asked the SWPC to do so), that would really be a monumental occurrence. You might want to start looking for clear skies.