The construction of the prototype of the core array of the Five-hundred-meter Aperture Spherical Radio Telescope, commonly known as "China Sky Eye", officially began on Wednesday. The plan is to harness the electromagnetic wave environment within a 5-kilometer radius surrounding FAST to build 24 telescopes of 40-meter aperture each, forming a core array that is expected to effectively enhance FAST's resolution, precise positioning, and detailed mapping capabilities.

The upgrading coincides with FAST's eighth anniversary. In the 1990s, when China's largest radio telescope had an aperture of less than 30 meters, Chinese astronomers proposed the construction of the "China Sky Eye", with the aim of surpassing the then world's largest Arecibo Observatory in Puerto Rico, which had a diameter of 305 meters when made operational in the 1960s and later expanded to 350 m. Siteselection for FAST began in 1994, the project received approval in 2007, construction commenced in 2011, it was made operational in September 2016, and, on passing national acceptance tests, became operational in 2020.

Since then, FAST has crossed many milestones to become the world's No 1 in the sector. Although FAST has high sensitivity, it lacks good resolution. Globally, the first phase of the construction of the Square Kilometer Array Observatory, split across South Africa and Australia, is likely to see completion in 2029, while the next generation Very Large Array observatory in the United States is scheduled for completion in 2035. They will have an edge over FAST in both resolution and sensitivity. It is for this reason that FAST is constructing the core array, which will enable it to see farther and more clearly.

The latest upgrading involves a low-cost and rapid implementation plan for building radio telescope arrays, which shows that top-level planning is essential for constructing large science devices. By setting outstanding goals and targeting real needs, China can build high-quality equipment to seize the commanding heights of international scientific competition.

- ECONOMIC DAILY