Earth is well overdue for a devastating solar superflare which could hit with more power than billions of atomic bombs, scientists have warned.
The most accurate study to date has revealed that superflares capable of wiping out power grids and satellites are far more common than scientists once thought.
Researchers now believe that these disastrous events occur once every 100 years, rather than once every 1,000 to 10,000 as was thought.
This means that Earth may soon be struck by a solar ‘tantrum’ releasing one octillion joules of energy – that’s one followed by 27 zeros.
That’s over 100 times more powerful than the Carrington Event of 1859 which collapsed parts of the telegraph network and even ignited sheets of paper in offices.
If an event of this strength were to hit Earth today, the impact would be even more devastating due to our increased reliance on satellite communication networks.
An impact from a superflare would overload power grids, knock satellites out of orbit, silence global communication networks, and ground aircraft around the world.
Co-author Dr Natalie Krivova, of the Max Planck Institute, says: ‘The new data are a stark reminder that even the most extreme solar events are part of the sun’s natural repertoire.’
Earth is overdue for a devastating superflare which could wipe out communication systems and knock satellites out of orbit, scientists have warned (stock image)
As this year’s extremely active Northern Lights have made clear, the sun is capable of chucking a huge amount of radiation our way.
However, the sun also has the ability to produce what scientists call superflares – enormous bursts of radiation and stellar material far bigger than anything seen in living memory.
The record of these events is written into the rings of prehistoric trees and layers or ice millennia-old glacial ice as layers of radioactive Carbon 14.
However, since modern observations of the sun’s radiation have only been available since the beginning of the space age, it is difficult to predict how often these superflares occur.
Instead of looking down to Earth to find answers, an international team of researchers led by the Max Planck Institute (MPI) looked up to the stars.
Co-author Dr Sami Solanki, director of the MPI, says: ‘We cannot observe the sun over thousands of years.
‘Instead, however, we can monitor the behaviour of thousands of stars very similar to the sun over short periods of time.’
The scientists recorded the data from 56,450 Earth-like stars seen by NASA’s Kepler telescope between 2009 and 2014.
Normally, the Earth’s magnetic field (right) protects us from the Sun’s radiation. However, during moments of intense activity called superflares, huge bursts of radiation and charged particles can wreak havoc on the planet
In total, this provided the team with the equivalent of 220,000 years of solar activity across stars with similar brightnesses and surface temperatures to our sun.
By watching how many of these stars sent out a superflare during the four-year period, the researchers were able to work out how often a star has one across the course of its life.
The researchers spotted 2,889 superflares on 2,527 of the observed stars, meaning that a superflare should occur roughly once per century.
First author Dr Valeriy Vasilyev, of the MPS, says: ‘We were very surprised that sun-like stars are prone to such frequent superflares.’
Earlier research had suggested that the average interval between superflares could be a thousand or even ten thousand years.
However, those studies didn’t have good enough data to figure out the exact origin of a solar flare so they could only look at stars which didn’t have any close neighbours.
The researchers claim that their new study is the most precise and sensitive to date.
There is also evidence of the arrival of vast solar storms right here on Earth.
Scientists used to think that superflares occurred once every 1,000-10,000 years but this new study suggests that they might occur as often as every century. A superflare would make the huge X-class flare of October this year (pictured) look tiny by comparison
A superflare would release the energy of several billion atomic bombs and transmit one octillion joules of energy, one followed by 27 zeros. This would be 100 times more powerful than the solar flare which caused the 1859 Carrington event which knocked out global telegraph systems
When a superflare erupts it can send a wave of highly energetic particles towards Earth in an event called a coronal mass ejection.
These particles slam into carbon atoms and produce a radioactive isotope called Carbon 14 (C14).
Because C14 has such a long half-life, scientists can spot it thousands of years later and work out when a solar flare hit and how strong it was.
Using these techniques, the researchers found five extreme solar particle events and three superflare candidates in the last 12,000 years, the most violent of which occurred in 775 AD.
However, that only yields a frequency of one superflare every 1,500 years.
Co-author Professor Ilya Usoskin, from the University of Oulu in Finland, says: ‘It is unclear whether gigantic flares are always accompanied by coronal mass ejections and what is the relationship between superflares and extreme solar particle events.’
This means that previous estimates which have looked at evidence from Earth might seriously underestimate how common superflares can be.
While it’s impossible to say when the sun’s next superflare might occur, the results could be catastrophic.
Solar flares can release large amounts of stellar material in events called Coronal Mass Ejections (pictured). When these hit Earth they create radioactive isotopes called Carbon 14. However, the researchers say that focusing on Carbon 14 has led scientists to underestimate how common superflares are
If a solar flare hits it will cause serious damage to our orbiting communications and GPS satellites. In 2031, the European Space Agency will launch a satellite which will sit nearer to the sun to give an advanced warning to those in low-Earth orbit
In 1989 a large geomagnetic storm led to a nine-hour energy outage across Quebec.
Likewise, in 2003, a flare caused Sweden to lose power for an hour.
The impact of a solar flare is particularly bad for satellites which sit beyond the protective shield of Earth’s atmosphere.
Not only can the impact of ionising radiation affect communications systems, but solar flares can even pull satellites out of orbit.
As the arrival of stellar material charges gasses around Earth, the atmosphere expands and exposes satellites in low-Earth orbit to increased drag.
This can lead to vital GPS and communications satellites drifting out of their proper orbits.
In 2031, the European Space Agency will launch the Vigil satellite which will be positioned at 60 degrees to the sun to provide an early warning of solar storms before they reach Earth.
This could buy vital time to power down energy grids and turn off satellites before the wave of energy hits.
SOLAR STORMS PRESENT A CLEAR DANGER TO ASTRONAUTS AND CAN DAMAGE SATELLITES
Solar storms, or solar activity, can be divided into four main components that can have impacts on Earth:
- Solar flares: A large explosion in the sun’s atmosphere. These flares are made of photons that travel out directly from the flare site. Solar flares impact Earth only when they occur on the side of the sun facing Earth.
- Coronal Mass Ejections (CME’s): Large clouds of plasma and magnetic field that erupt from the sun. These clouds can erupt in any direction, and then continue on in that direction, plowing through solar wind. These clouds only cause impacts to Earth when they’re aimed at Earth.
- High-speed solar wind streams: These come from coronal holes on the sun, which form anywhere on the sun and usually only when they are closer to the solar equator do the winds impact Earth.
- Solar energetic particles: High-energy charged particles thought to be released primarily by shocks formed at the front of coronal mass ejections and solar flares. When a CME cloud plows through solar wind, solar energetic particles can be produced and because they are charged, they follow the magnetic field lines between the Sun and Earth. Only charged particles that follow magnetic field lines that intersect Earth will have an impact.
While these may seem dangerous, astronauts are not in immediate danger of these phenomena because of the relatively low orbit of manned missions.
However, they do have to be concerned about cumulative exposure during space walks.
This photo shows the sun’s coronal holes in an x-ray image. The outer solar atmosphere, the corona, is structured by strong magnetic fields, which when closed can cause the atmosphere to suddenly and violently release bubbles or tongues of gas and magnetic fields called coronal mass ejections
The damage caused by solar storms
Solar flares can damage satellites and have an enormous financial cost.
The charged particles can also threaten airlines by disturbing Earth’s magnetic field.
Very large flares can even create currents within electricity grids and knock out energy supplies.
When Coronal Mass Ejections strike Earth they cause geomagnetic storms and enhanced aurora.
They can disrupt radio waves, GPS coordinates and overload electrical systems.
A large influx of energy could flow into high voltage power grids and permanently damage transformers.
This could shut off businesses and homes around the world.
Source: NASA – Solar Storm and Space Weather