Update: First 'extreme' event in 20 years produces spectacular auroras
Scientists are warning of possible disruption to critical infrastructure such as power grids and satellite communications due to a severe solar storm which is due to enter Earth’s atmosphere over the weekend.
British Geological Survey is forecasting a G4 geomagnetic storm to hit on Friday and Saturday, which could result in power cuts and may affect global communications and positioning systems as multiple waves of solar energy bear down on the planet.
The phenomenon – which occurs when the sun ejects a large bubble of superheated gas called plasma that travels towards the Earth – has prompted the US Space Weather Prediction Centre to issue alerts about the storm, the second-highest on a five-step scale, for the first time since January 2005.
The storm’s true power will only be known about 60 to 90 minutes before it hits Earth as satellites measure inbound bursts of energy from the solar flare's electrically-charged particles that interact with the planet's magnetic field.
Dr Ed Bloomer, an astronomer at Royal Observatory Greenwich, told The National that during severe solar storms, satellites may be placed into a “safe mode” to limit the impact.
“They might go into a safe mode or shutdown mode, or even in some circumstances be orientated slightly differently, so a different [side] of the instrument, more hardened against charge is facing the incoming solar wind,” he said.
Satellites are more hardened nowadays against the negative impact, he said.
However, the last time Earth was hit by a G5 storm – the worst on the scale – was October 2003, causing blackouts in Sweden and damaging transformers in South Africa.
This weekend’s solar storm is not expected to knock out power grids.
“It will probably be not very [disruptive], certainly in terms of the power grid side. Generally a G4 would not cause a problem to the level of blackouts, or things like that,” Dr Gemma Richardson, geomagnetic hazard specialist at the British Geological Survey, told The National.
“It might cause a little bit of a headache for some of the operations staff, in terms of balance, but I wouldn’t expect it to have much impact.”
The Kessler Effect
Experts previously predicted the Earth would face a major solar event this year that could have a potentially catastrophic impact on the global economy as the Sun reaches the peak of its 11-year cycle.
The “solar maximum” sends out radiation that could throw thousands of orbiting devices into “satellite drag”. Should scientists fears be realised, the impact is likely to be unprecedented because there are now 10 times more satellites in orbit than there were during the last cycle.
Predictions by a leading space weather scientist who spoke to The National from the British Antarctic Survey (BAS) suggest the upcoming cycle is more powerful than the last with “substantial risk” to satellites in low-Earth orbit.
The UK Risk Register, which grades events such as pandemics, terrorist attacks and nuclear war, has raised the level to “significant” for the impending solar maximum.
The event, which could last between two and three years, has the potential to cause the Kessler Event in which two satellites collide, with the debris having a cascading effect on others, potentially wiping out most of the orbiters. The Royal United Services Institute think tank in 2019 noted that the Kessler Effect – in which two objects colliding would cause potentially infinite other collisions – posed the same threat to the use of space as climate change or plastics in the oceans pose on Earth.
There are more than 7,000 satellites in space, with almost the entire globe dependent on them for mapping, timing and the internet.
“This could have quite a severe impact globally on how we run our lives, so it is a significant cause for concern,” said Prof Mervyn Freeman, BAS deputy leader of space weather.
Carrington Event
All recent solar flare events, including this weekend's, pale in comparison to the worst geomagnetic storm, which occurred in 1859.
Known as the Carrington Event, it resulted in an aurora so bright over the Rocky Mountains that it is said to have woken miners, who began preparing their breakfast because they thought it was morning. Auroras, typically confined to near the poles, were seen as far south as Colombia, near the equator.
“It induced enough charge to power telegrams without batteries. People used them to send messages with disconnected batteries,” said Dr Bloomer.
“It’s possible that you could see something that would rival the Carrington Event again.”
But if and when it does come, it will not be a surprise to scientists this time, he said.
“We have been keeping this under constant observation, so we get a picture of the Sun every few seconds,” added Dr Bloomer.
Experts have said trans-polar flights between Europe, Asia and North America will likely be rerouted to avoid increased radiation exposure for passengers and crews.
Solar storm 2024 produces spectacular Northern Lights – in pictures
And large parts of Asia, Europe and North America may be able to see an aurora, often called the Northern Lights, overnight where skies are dark and clear enough, the UK Met Office said.
The aurora could be visible across the entire UK.
A spokesman for the Met Office told The National that clear spells on Friday night will provide an “increased chance of aurora visibility” across Scotland, Northern Ireland and parts of northern England and Wales.
And given the right conditions, there is the chance the northern lights may even be visible further south, he said.
Auroras occur when the solar flare's electrically-charged particles collide with the Earth’s magnetic field, warming up gases in its atmosphere and making them glow, according to the Royal Observatory.
An aurora forms high above the Earth’s surface, about 130km above. But its tip may extend several thousand kilometres above, it said.
Its colours depend on the type of gases – nitrogen and oxygen are the most common in the Earth’s atmosphere.
Oxygen creates shades of green, while nitrogen can make the aurora appear purple, blue or pink.
Scarlet red is characteristic of a “particularly energetic” aurora, caused by oxygen interacting with solar particles at a high altitude, according to the observatory.
The culprit of the solar activity is a sunspot cluster visible on the right side of the sun’s disc that is 16 times wider than Earth. The sun, which rolls through an 11-year cycle in which the number of spots waxes and wanes, is approaching the peak of the current one that began in December 2019.
