The world's largest fully steerable radio telescope is under construction in northeast China's Jilin Province.Located in Huadian, Jilin, the radio telescope will be 120 meters in diameter and help scientists in understanding planets and asteroids more accurately.What is special about the new telescope is that it can send electromagnetic waves to celestial bodies and receive the return waves to measure the distances between the planets and the Earth accurately.Head of the project office for the radio telescope Luo Xuejiu said the site for the telescope was chosen in May this year and preliminary work had started since then.The pile foundation work has been finished, said Luo, adding that the installation, as well as adjustment and testing of the telescope, are expected to be completed in 2028.To explore the universe, China has built the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest single-dish and most sensitive radio telescope, in the southwestern province of Guizhou.The country is also building smaller but fully steerable radio telescopes in locations such as the Changbai Mountain Protection and Development Zone of Jilin, Xigaze of Xizang Autonomous Region, and Qitai of Xinjiang Uygur Autonomous Region.Compared with fixed radio telescopes of the same size, fully steerable radio telescopes can observe a larger part of the sky.