While it might look like a tranquil yellow ball from here, the sun is actually a raging inferno of intense magnetic forces and violent explosions.
So, although all life on Earth depends on the Sun to survive, it may one day be the thing that destroys us.
Scientists have recently warned that Earth is well overdue for a solar ‘superflare’ – a stellar explosion containing the energy of billions of atomic bombs.
When this happens, power grids will be damaged, satellites will fall from orbit, and the destruction of undersea cables could trigger an ‘internet apocalypse’.
From the superflare’s eruption from the sun, Earth will have just eight minutes before the first wave of radiation slams into the atmosphere.
However, the worst will still be yet to come as a vast wave of plasma and magnetic fields follows close behind, causing havoc for the planet’s electrical system.
The last time Earth was hit by a blast on this scale was during the 1859 Carrington Event, which was strong enough to give electric shocks to telegraph operators and set sheets of paper alight.
But experts now say that the planet could soon be hit by a solar flare more than 100 times more powerful and far more devastating.
What is a superflare?
A solar flare is a huge explosion on the sun’s surface which releases a huge amount of stored energy in a very short time.
These occur when magnetic fields become ‘twisted’ above cool patches of the sun’s surface called sunspots.
Within minutes these tangled fields heat material to many millions of degrees before snapping into a burst of radiation across the electromagnetic spectrum, from radio waves to X-rays and gamma rays.
However, that burst of energy is only part of the problem, since large solar flares are often accompanied by events called coronal mass ejections.
Professor Sean Elvidge, an expert on space weather from the University of Birmingham, told MailOnline: ‘Coronal mass ejections (CMEs), on the other hand, are huge clouds of charged solar plasma and magnetic fields hurled into space.
‘They move more slowly often taking one to three days to reach Earth, but can cause significant geomagnetic disturbances once they interact with our planet’s magnetic field.’
A so-called superflare is simply a particularly large solar flare capable of releasing one octillion joules of energy – that is one followed by 27 zeros.
Earth is overdue for a devastating superflare which could wipe out communication systems and knock satellites out of orbit, scientists have warned (stock image)
Previously, scientists had estimated that Earth would only experience one of these once every thousand to ten thousand years.
However, a recent study suggested that these events may occur as often as once every century.
Given that a superflare hasn’t hit Earth since 775 AD, we are well overdue for a run-in with one of these dangerous explosions.
So, if a superflare were to explode on the sun’s surface, here’s what would happen minute by minute.
Eight minutes since the superflare
Since electromagnetic radiation moves at the speed of light, we would only have eight minutes from the moment the flare bursts until we experience the first effects.
Dr Erika Palmerio, a research scientist at Predictive Science, told MailOnline: ‘From the flare we get radiation and solar energetic particles and those are the first things that are coming to us because they are the fastest.’
As this initial wave of X-rays and intense ultraviolet radiation arrives, it creates a build-up of electrons in a layer of the atmosphere called the ionosphere.
A superflare would release the energy of several billion atomic bombs and transmit one octillion joules of energy, one followed by 27 zeros. The first wave of X-ray radiation would hit Earth in eight minutes, causing widespread radio blackouts (stock imiage)
Those electrons interfere with radio signals moving around the planet, scrambling and decaying any messages humans might be trying to send.
That means the first sign a superflare had hit would be a sudden and total radio blackout on the sunlit side of Earth.
Dr Palmerio says: ‘That can be problematic if there is a disaster back on Earth, for example, a hurricane, since all those rescue teams communicate through radio.’
However, that lack of communication will become particularly dangerous when we consider what is still to come.
30 minutes since the superflare
Travelling just behind the solar flare’s first flash of radiation, the next thing to arrive would be a cloud of ionising high-energy particles.
Dr Palmerio says: ‘We have these solar particles which are launched by the flare and then accelerated as the CME moves through the lower atmosphere of the sun.
‘They’re not as fast as X-rays, but these particles are very energetic so within tens of minutes we can have a solar radiation storm.’
30 minutes after the superflare a radiation storm would hit Earth, exposing astronauts on the International Space Station (pictured) to a deadly dose of radiation
Down on the ground, we’re unlikely to see any impact from this radiation storm since the charged particles will be directed away by the Earth’s magnetic field.
However, passengers or crew on commercial flights are very likely to receive a substantially increased dose of radiation.
This would be especially dangerous for anyone flying near the poles where the charged particles would be most concentrated.
But the biggest risks of all would be faced by astronauts out beyond the protection of the atmosphere.
Anyone on the International Space Station (ISS) would be in real danger of receiving a deadly dose of ionising radiation as the radiation storm batters the planet.
Nor is this threat hypothetical since NASA astronauts have very nearly been killed by solar flares in the past.
In August 1972, Earth was hit by one of the worst solar storms in recorded history, knocking out long-distance communications across some US states.
Dr Palmerio says: ‘In that year we had the Apollo 16 mission in April and then Apollo 17 in December.
With radio blackouts on Earth, astronauts might not have time to receive a warning. But if they can, they would have about 30 minutes to either evacuate or shelter in a shielded area of the station
‘It’s been estimated that had that storm happened during one of those two launches, it would have been life-threatening for the astronauts.’
Additionally, since NASA uses radio frequencies to communicate with the ISS, astronauts might have no warning at all before receiving a deadly dose of radiation.
16 hours since the superflare
So far, most of the superflare’s effects have been limited to the upper atmosphere.
But now as the wave of charged plasma and magnetic fields which make up the CME roll towards Earth, things are about to become significantly worse.
Professor Elvidge says: ‘A strong CME usually takes between one and three days to reach Earth.
‘The exact timing depends on its initial speed and the conditions of the interplanetary environment, but travel times of around 36 to 48 hours are often typical for significant events.’
However, this is no typical event and in the case of a superflare we may have far less time to prepare.
Solar flares can release large amounts of stellar material in events called Coronal Mass Ejections (pictured). The fastest CMEs can hit Earth just 15-16 hours after the solar flare erupts
‘The fastest we have seen travel around 3,000 km/s and can reach the Earth in less than a day,’ says Professor Elvidge.
The fastest CME on record, the August 1972 event, took just 14.6 hours to reach Earth after leaving the sun.
Leaving a generous window, we might have only 16 hours between realising a flare has happened and the CME hitting.
When it does arrive, it is this part of the superflare that is likely to cause the most long-lasting damage.
Professor Elvidge says: ‘As a CME arrives, its interaction with Earth’s magnetic field can generate geomagnetic storms.’
These vast fluctuations in the magnetic field induce strong electrical currents in any long piece of metal on Earth including the wires in the power grids.
These power fluctuations can trip safety systems leading to regional outages or cascade failures and even set fire to the insulation surrounding electrical transformers.
As the CME hits the Earth’s magnetic field it creates a charge which induces a strong current in power grids on the ground. These surges could cause widespread blackouts around the world
One study estimates that a flare on the scale of the 1859 Carrington Event could leave 20 to 40 million people in the US without power for up to two years.
On the scale of a superflare, that could mean blackouts and power failures around the entire world lasting for years to come.
But the problems won’t be limited to the power grid, since some researchers also believe that a superflare could lead to an ‘internet apocalypse’.
While local internet connections have largely shifted over to non-conductive fibre optic cables, the subsea internet cables which join up the world are still made of copper.
These cables are equipped with repeaters every 30 to 90 miles (50-150km) to boost the signal over long distances which are very vulnerable to the effects of a solar flare.
If just one of these repeaters fails, the entire cable is rendered useless until it can be repaired.
That means that a failure rate of just one per cent would mean almost 15 per cent of subsea cables would be rendered useless.
This could cut entire parts of the globe off from the internet and take years to repair.
A recent study suggests that a solar storm could damage the undersea cables which provide the backbone of the internet. This could lead to entire parts of the world losing connection
17 hours since the superflare
Unfortunately for everyone on Earth, global power failures and the destruction of the internet are really just the start of the problems.
One of the biggest risks of a solar flare hitting Earth is that it will have a devastating effect on the network of satellites we use to communicate, navigate, and monitor the Earth.
Outside the protection of the atmosphere, satellites will be buffeted by all of the worst impacts of the solar Tsunami.
Professor Elvidge says: ‘Satellites might be affected almost as soon as the storming begins.
‘Increased radiation can disrupt onboard electronics, degrade solar panel efficiency, and interfere with communication and navigation signals.’
With an exceptionally large storm like a superflare, this could cause serious damage to systems we are extremely reliant on.
However, the real problems will begin about an hour later as the CME causes the atmosphere to warm and expand.
If a solar flare hits it will cause serious damage to our orbiting communications and GPS satellites. An hour after the CME arrives, satellites will begin to experience increased atmospheric drag and slip from their orbits
This plunges satellites in low-Earth orbit into a denser region of the atmosphere than they are used to moving through.
That increased drag slows down a satellite and deteriorates its orbit, slowly pulling it back down to Earth.
‘Depending on the CME’s intensity and a satellite’s resilience, these disruptions can last from a few hours to several days,’ says Professor Elvidge.
While most satellites won’t necessarily plummet to Earth, even small issues can lead to big problems since sensitive navigation systems are set to work at a certain altitude.
And with every satellite around Earth simultaneously falling towards the ground, significant disruption is almost inevitable.
Months and years afterwards
Depending on the alignment of the CME’s magnetic fields, the worst of the geomagnetic storm should subside between 10 and 24 hours after it began.
However, the lingering effects of the superflare could take months or years to fade.
Scientists demonstrate how observations of the rate of decrease of the Sun’s dipole magnetic field can be usefully combined with sunspot observations to predict when the ongoing cycle would peak. Their analysis suggests that the maximum of solar cycle 25 is most likely to occur in early 2024
Geomagnetic storms can cause dazzling aurora displays to appear at unusually low latitudes (pictured) but they can also damage sensitive computer equipment around the world, creating disruption that could take years to repair
Professor Alan Woodward, a computer security expert from the University of Surrey, told MailOnline: ‘You could get effects in the national grid but, probably more importantly, you’d also get them in delicate electronics like computers.
‘As a result, you’d have a lot of equipment that suddenly wouldn’t work properly.’
In the case of a superflare, Professor Woodward says this wouldn’t just be big things like your laptop but all the devices which make our modern world possible.
Professor Woodward says: ‘Think of your phone or the industrial control systems that are controlling traffic lights and heating systems, anything that uses computing could be damaged and cause a massive amount of disruption.
‘When you start looking at it, you suddenly realise how unbelievably dependent we are on modern communication.
‘Commerce, personal life, certain ways of working, certain ways of living; that would literally disappear.’
For humanity to recover, this would mean replacing all the damaged computer components while dealing with the fallout of massive power failures and the potential collapse of the internet.
And with every nation on Earth simultaneously competing for the same computer parts, that process could take months or years to complete.