China spent five years and close to $200 million to build its Five-hundred-meter Aperture Spherical Telescope, nicknamed FAST. It was a monumental undertaking, but the result is a true marvel of technology, and it’s the largest full radio telescope on Earth. Now, with China set for a final review of the completed project later this month, scientists say they’ve already used the telescope to detect a notoriously strange radio signal beaming through space.

Every once in a while, radio telescopes on Earth detect powerful signals from unknown sources. These Fast Radio Bursts (FRBs for short) are often singular flashes, but a few of them have been observed repeating at seemingly random intervals. One particular signal, known as FRB 121102, is notorious for popping up again and again, and China’s shiny new telescope heard it loud and clear.

Nobody really knows what creates FRBs, and that’s part of what makes them so exciting for scientists. The fact that most of them are one-off bursts, but that others like FRB 121102 continues to repeat makes the process that drives them even more mysterious.

“Once we pass this review, FAST becomes an accepted telescope for exploring the Universe,” Jiang Peng, chief engineer of FAST, said in a statement. “Fast has been open to Chinese astronomers since April 2019. After the National Construction Acceptance, it will be open to astronomers across the world.”

The science team using FAST detected FRB 121102’s telltale signals on August 29th, hearing “more than a few dozen bursts” of the signal. This particular event was especially significant because no other telescope on Earth has ever detected so many repetitions of the signal in such a short period of time, suggesting that the incredible power of China’s new telescope could help unlock the signal’s secrets.

Going forward, FAST will have its hands full, with researchers hoping to use it in the ongoing search for distant pulsars, elements like hydrogen, and of course additional Fast Radio Bursts.