China’s FAST telescope enlightens the world as the eye of heaven

At first glance, Pingtang county of Guizhou province doesn't look different from any other mountainous regions in southwest China. In late June, clouds fill the horizon with their melancholy folds, flowers bloom on the grassy marshland with cuckoos and cicadas never cease to end. Everything looks drowsy in the summer-exclusive heat.

FAST is hidden behind the greenery

Photo by WANG Yuhuan

A few steps later, however, a gigantic silver hemispherical 'cauldron' suddenly shows up, surrounded by rolling hills that nicely conceal this amazing structure.

FAST surrounded by mountains 

Photo by Xinhua News Agency

This cauldron is what called Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest filled-aperture and most sensitive radio telescope. FAST has an imaginative Chinese name, Tian Yan, which means the ‘Eye of Heaven’. Just as its name suggests, FAST will not only help mankind to explore the universe for neutral hydrogen, detect pulsars but possibly answer some unknows in the interplanetary space.

It took five years from the excavation of the site to the final completion in September 2016. But the vision of building a giant telescope in China can be traced back to 1990s. Since then, Chinese astronomical scientists have started the preparation work with an unprecedented path ahead waiting for exploration.

The founder of FAST: Nan Rendong(1945-2017)

Photo from Xinhua News Agency

“I am not a master of strategies, just a veteran with knowhows,” said Nan Rendong, the founder and chief scientist of FAST at that time.

It was Nan that led the whole team through the long slog. Countless difficulties occur some way along, but these Chinese scientists never thought of surrender. “When we come to hill, we cut a road; when the river is ahead, we build a bridge,” said Jiang Peng, who took over this cause as the chief engineer of FAST after Nan passed away at 72 because of lung cancer.

FAST sightseeing, Photo by Xinhua News Agency

Underpinned by such faith, 22 years later, FAST, which is the size of 30 football fields and consists of 4,450 reflecting units and 6,670 steel cables, has finally come into being. Taking advantage of the karst landform here, scientists have designed the telescope with a paraboloid surface that maximises reflection.

“The paraboloid helps with the focus and thus enables FAST to work more efficiently,” said Zhao Baoqing, head of the on-site office of FAST, “FAST could discover ca.150 pulsars a year, while other radio telescopes altogether could detect 50. “

On 31 March this year, after endless debugging trials, the FAST team announced that it would be officially open to the global scientific community and that any research organisation and individual with a need for the project could apply to FAST for observation.

“Once the application was issued, many foreign astronomical research teams which used to be limited by their geographical location, technical conditions or funding have submitted applications to China,” said Jiang.

According to Jiang Peng, the application was accessible from the end of March to mid-May, and “more than 200 requests have been received so far, among which more than 30 came from the abroad.” All the applications will be evaluated by top experts in their respective domains to ensure that the approved ones are in line with astronomical frontiers.

The chosen teams are expected to start using FAST in August this year and will receive 10% of the annual observing time, approximately 450 hours.

From being initially questioned both from home and abroad, to being taken seriously by the astronomical community worldwide, FAST has witnessed the rapid development of China’s cutting-edge technology and infrastructure construction. 

Jiang Peng introduces the construction of FAST

Photo by Luo Wangshu

“In the past, we were often the ones being helped by other countries. Now, the world will get benefit from China’s leading FAST project,” said Jiang Peng hopefully.

Astronomic researches don't remain within the borders of the countries where they occur — knowledge is a public good, with little regard for national boundaries. Humankind lives under the same sky, and the exploration of the stars has long been an eternal dream.

Exploration in the cosmos is not only related to mankind itself, but also closely associated with the fate of the planet. The space environment has a profound impact on the climate change and biological survival, which is a matter of concern for all mankind.

On January 18, 2017, President Xi Jinping explained his vision of building a “community with a shared future for mankind” at a speech in Switzerland, as China's answer to the challenges and problems facing the world. The Chinese government attaches great importance to the construction and development of FAST.

In 2016, President Xi sent a congratulatory letter when FAST was completed, and highly acknowledged the contribution of the FAST team in his New Year speech in 2016 and 2019 respectively.

 “The open of FAST can provide its own contributions and experiences to build a shared community in outer space, and is an important step towards a wider world for the human being,” added Jiang.

To date, China has been the “eye-opener” by building FAST, extending human wisdom to distant places that were once unimaginable, and transmitting the unfading hope from this generation to the next.

Reporter｜Wang Yuhuan, Xie Kaifan