Astronomers left baffled as China quietly sets up what could be the world's largest telescope

Astronomers are left surprised as China quietly advances plans for what could be the world's largest telescope.

In terms of space developments, China has been doing significantly well. Recently, the China National Space Administration (CNSA) launched a mission to collect samples from a nearby asteroid estimated to be worth $538 billion. This followed China's ambitious plans to build a nuclear plant on the moon as part of the Chang’e-8 mission.

Now, the nation is constructing what could soon become the largest optical telescope in the Northern Hemisphere - and perhaps, the world. High on the Tibetan Plateau, plans for the 14.5-metre Large Optical Telescope (LOT) have been kept under tight wraps.

Due to an unusual level of secrecy, official information is limited to brief mentions in Chinese academic abstracts and state media reports.

A solar radio imaging telescope array in Daocheng County, China. (NurPhoto/Contributor/Getty)

“As far as I can tell, it’s real. And it will certainly put China in the big leagues,” said Robert Kirshner, a cosmologist at Harvard University and executive director of the Thirty Meter Telescope (TMT), a major US-led observatory project.

According to a spokesperson for the National Astronomical Observatories of China (NAOC), as per Science, LOT is expected to be operational by 2030.

Additionally, the NAOC spokesperson declined to offer specifics, noting only that 'specific details of the project are still subject to further study.' LOT will be the centrepiece of China’s newest observatory hub Saishiteng Mountain, a 4,500-metre summit near the remote town of Lenghu in Qinghai province.

In 2023, NAOC announced a 2 billion RMB (roughly $277 million) investment in nine telescopic projects at Lenghu.

However, LOT is expected to outshine them all, overshadowing the existing 2.5-metre Wide Field Survey Telescope, which is used for spotting supernovae and near-Earth asteroids, as well as a 6.5-metre survey telescope studying dark energy and extrasolar planets.

China could be constructing the world's largest telescope. (Anton Winter/Getty)

By November 2024, a contract worth 159 million RMB (around $22 million) had been awarded to a Chinese Academy of Sciences (CAS) company to construct LOT’s dome.

Neither NAOC nor the lead developer, CAS’s Nanjing Institute of Astronomical Optics and Technology (NIAOT), have publicly shared the telescope’s full specifications. What is known is that it will be capable of both optical and infrared observations.

Sources suggest LOT will feature an imaging spectrograph, capable of taking detailed images while splitting the light into spectra that reveal the chemical makeup of planets and stars. “This kind of instrument is usually a workhorse that can do many different kinds of science,” says a US-based astronomer who asked to remain anonymous.

Kirshner describes China’s effort as a 'wakeup call for American science.' He added: “I don’t mean to scare people, but we really need to get moving.”