Witnessing a dazzling display of the Northern Lights with vivid sheets of colour dancing across the night sky is a real treat for those lucky enough to be in the right place at just the right time.
However, the charged particles hurled into space by our tempestuous Sun - the particles that create the aurora borealis - can also unleash very rare but extremely disruptive events here on Earth. Electricity supplies, satellites, and air travel can all be affected by the most violent solar storms.
Recently, 6,000 planes were grounded by Airbus, requiring a software update after one of their planes experienced a sudden drop in altitude in October, thought to be caused by interference from intense solar radiation. This kind of disruption is something that scientists and governments are actively researching and planning for.
What damage can solar storms cause?
The UK government publishes The National Risk Register - a list of serious hazards that could affect the country at some point in the future. It catalogues the sorts of nightmare scenarios that give politicians sleepless nights. Alongside risks such as nuclear incidents, terrorist attacks, and outbreaks of disease sits the threat of severe space weather.
Much of the planning for severe space weather is based on the Carrington Event of 1859, the most intense geomagnetic storm in recorded history. This created rapid variations in the Earth's magnetic field that caused electricity to be generated in long wires. Telegraph operators suffered electric shocks, pylons were seen to spark, and some conversations between operators could carry on while batteries were disconnected.
With today's advanced technologies, the effects of a similar event would be far more disruptive. Satellites can be badly affected; strong solar storms can cause the Earth's atmosphere to expand out into space, which creates more drag for satellites. This can cause them to slow down enough for some to deorbit and fall back to Earth. This is not just theoretical; in February 2022, a solar storm led to the loss of 38 satellites.
Additionally, radio communications can be severely impacted, with GPS systems lost or disrupted for many days – affecting navigation for personal vehicles and potentially creating gridlock in cities. Without GPS, air travel would be fundamentally compromised.
In March 1989, the Canadian province of Quebec faced a power cut caused by space weather, leaving millions without power or heat for nine hours. Such events highlight the real and present danger that solar storms pose to critical infrastructure.
What are the chances of another Carrington event?
In July 2012, a Carrington-class event narrowly missed hitting the planet. The sun rotates once every 25 days and, by good luck, the active area of the sun was not pointing straight at Earth – so this dangerous space weather was flung harmlessly beyond our planet. Researchers suggest that we might even face events much larger than the Carrington Event.
Named after the scientist who discovered them, Miyake events could pose a threat to modern society on a scale that is hard to comprehend. With the last one identified around a thousand years ago, many experts contend it's simply a matter of time before we experience such a catastrophic event.
