Could Our Sun Release a Massively Destructive Superflare?

Maybe.

Sun and coronal mass ejection, illustration
Illustration of a coronal mass ejection (CME) emanating from the sun. MARK GARLICK/SCIENCE PHOTO LIBRARY / Getty Images

A spectacular tantrum from a distant star is making scientists a little anxious about our own fiery friend.

The star in question — AD Leonsis, about 16 light-years away in the constellation Leo — is a red dwarf, meaning it’s cooler than our sun. But that also means it’s a lot less stable, producing more destructive bursts of energy, called solar flares.

A paper published this month in Publications of the Astronomical Society of Japan describes AD Leonsis as producing the granddaddy of all flares: a superflare.

The researchers had planned to spend a week eyeing Leonsis, expecting to witness plenty of regular flares. They were astonished, according to Forbes, to spot a superflare on day one.

It was the kind of blast, wrapped up in near-incalculable energy that tells astronomers, "Nope, no life in these parts."

Orbiting planets would have a hard time hosting life as we know it if they had to weather solar death rays on the regular.

Which might cause you to wonder about our own favorite ball of plasma. 

The thing is our sun has been a relatively cool customer lately, generating less energy over the last year or so. Some scientists even suggest the lull, called a solar minimum, may even extend to a century.

But it’s possible, at least in theory, for our sun to produce a superflare. Like most stars, it makes these fiery outbursts pretty routinely. 

The size of a solar flare in relation to Earth.
A solar flare, as this rendering reveals, is many times more massive than Earth. Getty Images / Handout

“Solar flares are sudden explosions that emanate from the surfaces of stars, including our own Sun,” the study’s first author, Kosuke Namekata, explains in the press release. “On rare occasions, an extremely large superflare will occur. These result in massive magnetic storms, which when emitted from our Sun can affect the Earth’s technological infrastructure.”

Indeed, NASA describes a solar flare as the biggest explosive event in our solar system. When a flare erupts, that intense burst of energy lights up every wavelength of the visual spectrum. In case that isn’t enough drama, the sun will occasionally hurl billions of tons of matter into space, in what’s called a coronal mass ejection (CME).

Did we mention that all those particles are accelerated at millions of miles per hour?

And that’s just the garden variety flare — the kind the sun issues as often as a couple of times a day. A superflare, like the one spotted on Leonsis, produces as much as 10,000 times the energy. For that reason alone, a star regularly making that kind of outburst wouldn’t likely allow for life on orbiting planets.

But could our sun produce such a ferocious amount of energy? And how about all that life that currently happens to be teeming on the planet about 93,000,000 miles away from it?

That Time When the Sun Melted Telegraph Wires

So far, the most powerful flare we’ve detected was back in 1859. Known as the Carrington Event, it was accompanied by an invisible wave of extremely destructive energy. That would be the mass coronal ejection accompanying the flare. As NASA describes it, "skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.”

The CME’s magnetic energy also surged through telegraph lines, melting wires and shutting down communications.

And that was just a really big flare in a time when communications infrastructure was still in its infancy. Today’s satellites, cell phone towers, radar, and GPS receivers are all vulnerable to those extremely energetic particles accompanying a major solar flare, NASA notes. As well, astronauts walking in space would be imperiled by the blast. In all, the space agency estimates a major electromagnetic would rack up anywhere from $30 to $70 billion in damages.

The good news is a fleet of spacecraft, including the pioneering Parker Solar Probe, are monitoring and studying the sun.Scientists hope to unravel the origins of solar flares. And, by determining how they develop, we may someday be able to brace ourselves and our precious things, from the Big One.

But just how big could that be? Are we talking superflare?

In a word, maybe. Superflares aren’t confined to Red Dwarfs like AD Leonsis. Yellow stars, like our own, are also known to issue them. 

Last year, a research paper from Colorado University suggested the possibility that the sun could clear its throat rather violently — and send a massive cloud of plasma and magnetic energy our way.

“Our study shows that superflares are rare events,” lead researcher Yuta Notsu, of CU Boulder’s Laboratory for Atmospheric and Space Physics, noted in a 2019 release. “But there is some possibility that we could experience such an event in the next 100 years or so.”

But it's a remote one. Mostly, because we happen to have a mellow yellow sun. It rotates relatively slowly. Hence its magnetic field is weaker and less prone to building up as much unruly magnetic energy.  

"When our sun was young, it was very active because it rotated very fast and probably generated more powerful flares," Notsu explained in the release. 

“Young stars have superflares once every week or so,” he added. “For the sun, it’s once every few thousand years on average.”

Indeed, these days, a humble flare or two should suffice in clearing our favorite star's head.