China's colossal radio telescope just heard a bizarre signal in space

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 o...