ramy inocensio paid a visit. >> reporter: the world's biggest single disc radio telescope, more thane football fields across, scanning our skies. its chinese name means eye of heaven. over a year to detect fast radio bursts, ripples in space-time and search for signs of extraterrestrial life. became operational last january. cbs news gained access only because it was offline for maintenance. see that the huge steel ring? six towers piercing the clouds? they're spectacular and gigantic. we're all so happy. this is the apple of this cosmic eye, 30 ton feed cabin hoisted by towers nearly 500 feet up, job to collect data from the universe reflected from the disc. breathtaking to see it all complete. what we don't see is amazing. mandatory radio quiet zone three miles every direction from here. scientists want to listen to very faint radio waves from millions of light years away, not from someone's cell phone down the road. it's now even more important after the collapse of aricibo telescope in puerto rico, plummeted through the disc after the cables failed. he said he grieved for the los