Largest solar flare in more than a decade hits Earth, creating a spectacular sight

11 Sep 2017

An M-class flare exploding on the left side of the sun, captured on 5 November 2014. Image: NASA/SDO

The largest recorded example of a solar flare has struck Earth. Thankfully, its effects have been pretty spectacular.

While scientists debate over what can be done about our influence on the onset of noticeable climate change, nothing can be done to prevent the potential catastrophe brought on by future sun flares except sit back, watch and prepare for the worst.

So, while it might sound quite dramatic that the largest solar flare in more than a decade – 12 years to be exact – was recorded on 6 September 2017 over a 48-hour period, it was actually harmless to those of us on Earth.

A team of researchers from the University of Sheffield and Queen’s University Belfast (QUB) caught the X-class flare in action using the Swedish Solar Telescope in La Palma in the Canary Islands, and its effects were nothing short of spectacular.

It provided a very rare treat for stargazers seeking the Aurora Borealis as the solar winds bombarded our planet, creating some stunning displays of light and colour.

At its peak, the solar flare reached an energy level of X9.3, or nine times more powerful than an X1 flare, which, even at its most average eruption, reaches power equivalent to the explosion of billions of hydrogen bombs.

In the nick of time

As the researchers explained, actually capturing the birth of such a solar flare was a rather difficult process as a typical X-class flare can burst and reach its peak in as little as five minutes, meaning astronomers need to act fast to ensure they catch the crucial opening moments of its evolution.

“It’s very unusual to observe the opening minutes of a flare’s life,” said Dr Chris Nelson, one of the observers of the flare.

“We can only observe about one 250th of the solar surface at any one time using the Swedish Solar Telescope, so to be in the right place at the right time requires a lot of luck. To observe the rise phases of three X-classes over two days is just unheard of.”

Aside from just glimpsing something spectacular, getting the solar flare on camera is important in helping to predict when they might occur, which will be vital if one is of such severity that it could affect GPS satellites and power grids on Earth.

Dr Aaron Reid of QUB said: “The number of active regions, where flares occur, is low, so to have X-class flares so close together is very usual. These observations can tell us how and why these flares formed so we can better predict them in the future.”

Colm Gorey was a senior journalist with Silicon Republic