Something has breathed new life into a faraway cosmic mystery machine and caused it to repeatedly hurl tremendous amounts of energy into the void.

It’s not clear exactly what that object is, but scientists refer to the observable phenomenon as a fast radio burst: a fleeting but extremely powerful blast of radio waves. In this case, astronomers caught a rapid stream of radio bursts coming from a galaxy about three billion light-years away.

Scientists with the Breakthrough Listen project made the discovery because, fortunately, they had a pretty good idea where to look. The team had tuned the giant Green Bank Telescope in West Virginia to a spot on the sky where a fast radio burst known as FRB 121102 had previously been singing to the stars.

Of the roughly two dozen bursts discovered so far, FRB 121102 is the only one known to play on repeat. Because of that, it’s the only burst with a known home galaxy, which was identified in late 2016 after scientists used several telescopes to pinpoint its origin.

After that discovery, FRB 121102 fell silent for a good stretch of 2017. Though it had previously offered periods of quiescence and activity before, its silence was alarming.

“We feared that our opportunity to study it has passed,” says UC Berkeley’s Casey Law. “This new detection suggests that FRB 121102 is coming back into an active state and will be easier to study how and what is producing these powerful bursts.”… see more

source: national geographic