China to build world’s biggest radio telescope

New Scientist : China has started building the world’s biggest and most sensitive radio telescope—the Five-hundred-meter Aperture Spherical Radio Telescope, an instrument that promises to transform radio astronomy, writes Anil Ananthaswamy for New Scientist. The instrument, which will be located near the city of Duyun in Guizhou Province, will allow astronomers to peer three times farther into the universe than any previous telescope. Although its dish will be fixed in an 800-meter-wide karst—a sinkhole formed by eons of water eroding limestone bedrock—a series of large motors will be able to change the shape of the dish’s reflective surface, allowing it to scan large swaths of the sky.