In 774 AD, an enormously powerful explosion of matter and energy crashed into Earth.
Nothing like this had been felt on this planet for 10,000 years. A mixture of high-energy light and enormously accelerated subatomic particles, when this wave hit the Earth, changed our atmospheric chemistry enough to be measured centuries later.
Our pre-electronic societies were not totally affected by this. But if such events were to take place today, the results would be bad.
It was first discovered through an analysis of tree rings, of all things. The scientists found that the level of carbon-14, a carbon isotope, was much higher in the rings that year than usual. A few years later, observing air samples from the ice cores, the scientists saw that there were also high levels of beryllium-10 and chlorine-36.
The common factor in all of these elements is that they are created when extremely high-energy subatomic particles impact the Earth’s air and soil. They hit the nuclei of the atoms and change them, creating these isotopes. The only way to get particles at energies like this is from space, where the powerful magnetic fields of exploding stars, for example, can accelerate particles to such high speeds. We call them isotopes cosmogenic, made from space.
What could have created the space storm in 774 AD? The obvious candidate for such a thing is a very powerful solar flare, an explosion in the Sun created when intense magnetic field lines become entangled and short-circuited, releasing huge explosions of energy and particles. But the event of 774 was so powerful that at first scientists were skeptical that it could be a blast. Once any other type of astronomical phenomenon was ruled out, however, only one flame remained.
A team of scientists has reviewed the records to examine other such events in hopes of classifying this flare compared to other known flares. What they found is that this event was far more powerful than even some relatively terrifying modern flares.
For example, in 1989 the Sun erupted in a powerful series of flares, as well as in a huge coronal mass ejection (or CME), where billions of tons of hydrogen plasma are expelled at high speed. Carrying its own magnetic field space time it crashed into the Earth’s magnetic field, affecting it so deeply that electric currents were induced beneath the Earth’s surface. He called geomagnetically induced currents, this additional electrical power blew up the transformers in Quebec and caused a power outage that lasted for hours.
February 1956 was the most powerful solar storm of the modern era, which was easily twice as strong as the 1989 event. Our power grid was not as used at the time, so it did not cause the same kind of damage as the 1989 event, but it was a huge event.
Using various methods to characterize the 1956 storm, including measurements in visible light, radio waves, changes in the Earth’s ionosphere (a layer of high-altitude ionized air that, when rapidly changing, can affect ground magnetometers magnetic field strength)), and much more, they found the event of 774 AD to be astonishing 30 to 70 times stronger. That means it was likely 100 times stronger than in 1989.
It is not clear how long the flare lasted; the strongest grow and decay in a matter of hours. But the total energy released in this flame was almost the same as that radiating all over the Sun in a second: 2 x 1026 Joules, or the equivalent of approximately 100 billion megaton bombs that fire.
This takes a lot of energy. Enough to power the entire planet (given our current energy use) 300,000 years.
Yegads.
A flare like this is called a superflare, and until now it was not thought that the Sun could produce them (other stars that are more magnetically active do so quite often). Scientists think that the flare 774 may have been a special circumstance, in which a powerful flare occurred near a flaming gas called a filament, which struck it and accelerated the protons it contained to obtain such energies. high.
Actually, this is a relief. I prefer that it be difficult for the Sun to do this.
Such an event that happened today would be catastrophic. It could remove numerous satellites (particles and high-energy radiation can reduce even hardened electronics) and cause widespread blackouts. These could take a long time to fix, as larger transformers that use power grids cannot mass produce. Some scientists calculated that passengers on international aircraft flights could receive a vital dose of radiation within hours of such an event.
The effects on the Earth can be difficult to determine; in part, it depends on whether the flare and the magnetic polarity of CME (the north-south part of the magnetic field) are capable of coupling with the Earth’s magnetic polarity. If you do, we will get the shutdowns and other damage. But some of the effects occur anyway.
I will note that we have not seen such a powerful event since 774, although many have been quite strong. The Sun erupted in 2012 in a coronal mass expulsion that, if it had hit the Earth, would have been worse than the 1989 event. Fortunately it was expelled in another direction.
But it is clear that the Sun can have some pretty big rages and that we need to take it seriously. Certainly, solar astronomers do, and as the Sun rises to its most recent magnetic cycle, they are looking at our star with all that they have. We do not know how strong this cycle will be; one prediction is that it won’t be a big deal, but another says it will be a lot.
See me. Of course we need to learn a lot more about the Sun. It is no exaggeration to say that our modern life depends on it.