The greatest mystery of modern radio astronomy comes down to just three letters: FRB. They stand for fast radio bursts, signals that continue to defy explanation. As the name implies, these bursts of radio waves last just a millisecond or two. They’re also incredibly strong, among the brightest radio sources in the sky. That’s despite traveling an incredible distance, up to billions of light-years. Do the math, and it’s clear how powerful these things are. One FRB can easily broadcast more energy in a moment than the sun produces in a day.
Visible light is only a part of the electromagnetic spectrum, but if your eyes could see radio waves, you’d probably spot FRBs in the sky all the time — thousands of them a day, from all directions. Despite their prevalence, though, no one had ever detected one — or even heard of one — as little as 20 years ago. Today, it remains unclear what FRBs really are. But thanks to improved technology and some lucky breaks, astronomers are finally on the verge of finding out.
