The Daily Telegraph
Shock and aurora as Northern Lights head south
A rise in magnetic activity on the Sun makes the polar phenomenon more visible as far as the Cornish coast
‘We’re two years away from the predicted maximum, so the prospect looks good that more people will see the Northern Lights’
THE Northern Lights are likely to be more visible than usual from southern England over the next two years, as the Sun becomes more active, astronomers have predicted.
Earlier this week, residents in Kent, Cornwall, Cambridgeshire and Shropshire reported green, pink and purple skies as the aurora borealis made an unexpected appearance in the south.
During active times, large solar storms can fling huge clouds of charged particles towards the Earth, triggering the auroras in the northern and southern hemispheres.
Although most associated with Arctic locations such as Norway and northern Canada, the light display is often visible in the North of England and Scotland during the winter months.
It is rare for magnetic activity in the Sun to be strong enough for the phenomenon to be seen so far south. However, the Sun’s magnetic field goes through a cycle approximately every 11 years and that is set to peak in July 2025.
Astronomers say that increased activity this far in advance of the “solar maximum” bodes well for future displays over Britain.
Dr Robert Massey, deputy executive director of the Royal Astronomical Society, said: “The displays we have seen show that the Sun is getting more active, and [by] more than expected.”
He added: “There had been predictions that this cycle could be really weak but we’re two years away from the predicted maximum and there is more activity than was forecast, so the prospect looks good that more people will get to see displays of the Northern Lights.” Solar cycles occur because the Sun’s magnetic poles flip periodically, with activity peaking just as the North and South Poles swap places.
The current cycle began in December 2019 and is expected to continue over the next two years, increasing the chance of the solar flares and plasma bubbles that send electrically charged particles shooting towards Earth.
Auroras are caused when those particles excite molecules in Earth’s upper atmosphere, causing them to glow, the colour depending on what chemicals are hit. Red and pink light is produced from collisions with nitrogen molecules at low altitudes, while green is produced by oxygen molecules higher up.
Sunday night’s display was particularly striking as it coincided with a cloudfree sky, clear air and a dim Moon.
Dr Dan Brown, associate professor in astronomy at Nottingham Trent University, said the Northern lights so far south would remain rare since this week’s events were caused by one specific sunspot belching out larger than normal amounts of charged particles.
This was expected to be even stronger last night. Sunday’s activity was classed as “moderate” and tonight’s expected to be “strong”. There were only about 200 strong days in every 11year cycle, Dr Brown said.
Mark Gibbs, head of space weather at the Meteorological Office: said: “What we saw on Sunday was a bubble of magnetised plasma particles that came off the Sun, and they happened to be heading towards the Earth in this instance.
“It took about two days for those particles to arrive from the Sun, then the particles enter the Earth’s upper atmosphere and excite atoms. The most common sight is green, which is the result of oxygen atoms being excited. Last night, we saw some reds and purples, indicative of nitrogen atoms being excited.”
Although heightened solar activity can bring spectacular skies, it can also pose a risk to satellites, aircraft and power grids.
The largest solar storm ever recorded, the Carrington Event in 1859, knocked out telegraph systems and even set fire to paper in offices.
Historically, extreme space weather has caused widespread disruption, with a geomagnetic storm leaving six million people without power in 1989. In 1972, astronauts on one of Nasa’s Apollo missions narrowly missed being exposed to deadly radiation and, in 2003, solar flares forced the crew of the International Space Station to take cover.
Dr Massey said: “The Northern Lights are a visible reminder that although the Sun keeps us warm, and can trigger these extremely beautiful displays, it can also have these other effects.
“Space weather is now on the national risk register because it can be such a problem for power grids and satellites.”