Superflares Erupt From Stars Like Our Sun Once Every 100 Years

Our sun is a violent place. Bursts of radiation snap off the solar surface with the strength of millions of volcanic eruptions. Hot plasma churns and spews, streaming particles that can harm astronauts and satellites in space and damage electrical systems on the ground. They can also brighten up our skies with colorful lights.

But scientists have observed even bigger explosions with the power of a trillion hydrogen bombs from other stars that they call superflares. And while a superflare has yet to be observed from our own sun, astronomers wonder if it is capable of such an extremity, and if so, when one might occur.

A paper published in the journal Science on Thursday offers more insight. Researchers determined that stars similar to the sun generate superflares roughly once a century, a rate much higher than expected. The findings suggest that we could be due for an extraordinarily powerful solar event sooner rather than later.

“We are in the space age,” said Yuta Notsu, an astrophysicist at the University of Colorado Boulder and an author of the paper. “So I think it’s good to estimate low-probability but large-impact events,” which can help space weather experts better quantify any potential risk posed to our planet, he said.

Solar flares occur when the sun’s magnetic field twists and snaps, sending a burst of energy, often accompanied by an outflow of charged particles, into space. If these particles interact with Earth’s atmosphere, evidence of the event can end up nestled in tree rings or ice cores.

But particles aren’t always ejected, nor are those events always directed toward Earth, making it difficult for scientists to draw conclusions about the sun’s behavior from natural records. A better method, according to Valeriy Vasilyev, an astronomer at the Max Planck Institute for Solar System Research in Germany who led the study, is to look at stars in the Milky Way that behave like our own sun.