The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the largest radio telescope in the world, located in Guizhou province, China. It was completed in 2016 and has been in operation since then. The diameter of the main dish is 500 meters, making it the largest single-dish radio telescope in the world. The construction of FAST cost about 1.2 billion yuan ($170 million) and was funded by the Chinese government.

　　FAST is a major innovation in the field of radio astronomy and has made significant contributions to the study of the universe. It has a much higher sensitivity than other radio telescopes and can detect weaker signals from distant celestial objects. This allows astronomers to study the universe in greater detail and to gain a deeper understanding of the formation and evolution of galaxies, black holes, and other celestial objects.

　　One of the most important achievements of FAST is the detection of pulsars. Pulsars are rapidly rotating neutron stars that emit powerful radio waves. They are important objects for studying the composition and structure of neutron stars and have been used to test general relativity and other theories of gravity. FAST has detected more than 200 pulsars, including some of the most distant and energetic pulsars known.

　　FAST has also been used to study the distribution of galaxies in the universe and to search for signs of extraterrestrial intelligence. In 2019, FAST participated in the Breakthrough Listen project, which aims to detect radio signals from distant civilizations. Although no signals were detected, the project has shown the potential of FAST for searching for extraterrestrial intelligence.

　　The construction of FAST was not without its challenges. The site chosen for the telescope is in a remote and mountainous area, and the construction required the movement of large amounts of earth and rock. The engineers also had to overcome the challenge of building a large and stable structure that could withstand the strong winds and heavy rain in the area.

　　Despite the challenges, the construction of FAST was a success and has made significant contributions to the field of radio astronomy. It has allowed astronomers to study the universe in greater detail and has shown the potential of China as a leader in the field of scientific research. The future of FAST is bright, and it is expected to continue to make important contributions to our understanding of the universe.