A Massive Blast of Interstellar Energy Hit Earth in 2022. As We Learn More, It Gets Weirder

Imagine a camera flash that was so strong and so bright it could travel halfway across the universe, and not only hit Earth with enough energy that we can see it, but register as the most powerful burst of its kind ever detected.

That's essentially what happened in 2022, except instead of a camera flash, the pop was a fast radio burst, a mysterious cosmic phenomenon that is both little understood and incredibly rare. No one is sure what causes them, but there are theories. And this burst threatens to upend them all.

The burst, FRB 20220610A, was detected in June 2022 by a radio telescope in Australia. Observations concluded it must have come from very far away, yet it carried four times the energy of closer fast radio bursts, a fact that baffled astronomers. Were their theories about fast radio bursts wrong? Or was this one just bright enough to be detected?

Now, using the Hubble Space Telescope, they think they know exactly where this fast radio burst came from: A collection of galaxies that existed when the universe was about 5 billion years old (it is about 13.5 billion years old now).

And this is, from what little we know about fast radio bursts, very bizarre. Every previous fast radio burst has been found emanating from one galaxy in isolation, not a multi-galaxy system.

The astronomers who took the Hubble images presented their results at the 243rd meeting of the American Astronomical Society on Tuesday, and the study's lead author, Alexa Gordon of Northwestern University, said the discovery would have been impossible without the space telescope. 

"Without Hubble’s imaging, it would still remain a mystery as to whether this was originating from one monolithic galaxy or from some type of interacting system. It’s these types of environments —these weird ones— that are driving us toward better understanding the mystery of FRBs," she said in a statement.

To make matters weirder still, it may be possible these galaxies are colliding with one another, a condition that could be the trigger for the burst. While no one is sure what causes a fast radio burst, most scientists think they likely involve a black hole or an extreme form of a neutron star called a magnetar. These are intensely magnetic, dense and tiny remnants of dead stars. Hubble scientists explain that if a magnetar were located between the Earth and the moon, its field would be so strong that it would erase the magnetic strips on the credit cards of everyone on Earth.

It's possible the colliding galaxies triggered a magnetar's magnetic field to snap: Much like how the sun gives out solar flares when that happens, a magnetar might unleash a fast radio burst. Or it could be in the process of getting devoured by a black hole. Or the cause could be something else that astronomers can't imagine yet.

Scientists hope to solve the mystery as we see more of these events.

“We just need to keep finding more of these FRBs, both nearby and far away, and in all these different types of environments,” said Gordon.