China’s Five-hundred-meter Aperture Spherical Telescope (FAST), the world’s largest and most sensitive single-dish radio telescope, is set for a significant upgrade that will increase its observational power by 30 times. The upgrade involves constructing 24 fully steerable radio telescopes, each 131 feet in diameter, around the existing FAST structure in Guizhou province. This new array will function as a 6.2-mile-wide telescope, vastly enhancing FAST’s resolution and allowing it to study cosmic phenomena like gravitational waves, fast radio bursts, and black holes in unprecedented detail.
Boosting Resolution and Sensitivity
FAST has been renowned for its exceptional sensitivity, which makes it highly effective at detecting faint cosmic signals. However, its resolution—the ability to distinguish fine details in those signals—lags behind other top-tier telescope arrays. The addition of the new telescopes aims to address this limitation. By enhancing resolution, FAST will be able to pinpoint the exact location of phenomena such as fast radio bursts, offering a clearer view of the cosmos.
“The Chinese-designed array will combine the unprecedented sensitivity of FAST with a high angular resolution, thereby exceeding the capabilities at similar frequencies of next-generation arrays in the world,” reported China’s Xinhua news agency. Jiang Peng, director of the FAST Operation and Development Centre, highlighted that this upgrade would allow scientists to study cosmic events with greater detail and clarity, effectively giving astronomers a sharper lens on the universe.
Competing in Global Radio Astronomy
The upgrade comes amidst intense global competition in radio astronomy, with major projects like the Square Kilometre Array (SKA) in the southern hemisphere and the Next Generation Very Large Array (ngVLA) in the United States pushing the boundaries of astronomical research. Chinese scientists aim to preserve FAST’s competitive edge, particularly in the low to mid-frequency range.
“FAST is helping mankind explore the origins, evolution, and structure of the universe, providing crucial observational data for understanding pressing scientific questions,” said Chen Xianhui, an academician at the Chinese Academy of Sciences.
Challenges in Advancing Technology
Despite the promising outlook, the expansion presents significant technical challenges, particularly in developing high-performance room-temperature receivers and advancing data processing for synthetic aperture telescopes. The receivers are crucial for capturing faint radio signals, but they must operate efficiently at room temperature to minimize noise interference. Furthermore, advanced data processing techniques are essential to merge information from the array into clear, high-resolution images of the cosmos.
Expanding the Frontier of Discovery
Since its completion in 2016, FAST has become a leading tool for radio astronomy, discovering over 900 pulsars—more than triple the number found by other telescopes during the same period. It has also made groundbreaking discoveries, including the first detection of a black hole “heartbeat” in the radio wave band and identifying a pulsar binary system with the shortest known orbital period. With the new upgrade, FAST is poised to continue expanding humanity’s understanding of the universe, maintaining its status as a cornerstone of global scientific exploration and collaboration.
Through this expansion, China not only aims to solidify its leadership in radio astronomy but also to inspire future generations of scientists by pushing the boundaries of what is possible in the study of the cosmos.
