China Built the Worlds Largest Telescope. Then Came the Tourists


“I hope we go inside this golf ball, ” Sabrina Stierwalt joked as she and a group of other radio astronomers approached what did, in fact, appear to be a giant golf ball in the middle of China’s new Pingtang Astronomy Town.

Stierwalt was a little drunk, a lot full, even more tired. The nighttime scene felt surreal. But then again, even a sober, well-rested person might struggle to make sense of this cosmos-themed, touristy confection of a metropolis.

On the group’s walk around town that night, they seemed to traverse the ever-expanding universe. Light from a Saturn-shaped lamp crested and receded, its rings locked into support pillars that appeared to make it levitate. Stierwalt stepped onto a sidewalk, and its panels illuminated up beneath her feet, leaving a road of lights behind her like the tail of a meteor. Someone had even brought constellations down to Earth, linking together lightings in the ground to match the patterns in the sky.

The tourist town, about 10 miles from the telescope, illuminations up at night .
Credit Intentionally Withheld

The day before, Stierwalt had traveled from Southern California to Pingtang Astronomy Town for a conference hosted by scientists from the world’s largest telescope. It was a new designation: China’s Five-Hundred-Meter Aperture Spherical Radio Telescope, or FAST, had been completed simply a year before, in September 2016. Wandering, tipsy, around this shrine to the stars, the 40 or so other foreign astronomers had come to China to collaborate on the superlative-snatching instrument.

For now, though, they wouldn’t get to see the telescope itself, nestled in a natural enclosure called a karst depression about 10 miles away. First things first: the golf ball.

As the group got closer, they insured a red carpet unrolled into the entrance of the giant white orb, guarded by iridescent dragons on an inflatable archway. Inside, they buckled up in rows of molded yellow plastic chairs. The lights dimmed. It was an IMAX movie–a cartoon, with an animated narrator. Not the likeness of a person but … what was it? A soup bowl?

No, Stierwalt realized. It was a clip-art version of the gargantuan telescope itself. Small cartoon FAST flew around big cartoon FAST, describing the monumental feat of engineering simply over yonder: a giant geodesic dome shaped out of 4,450 triangular panels, above which receivers collect radio waves from astronomical objects.

FAST’s dish, nestled into a depression, is made of thousands of triangular panels .
VCG/ Getty Images

China spent $180 million to create the telescope, which officials have repeatedly said will stimulate the country the global leader in radio astronomy. But the local government also expended several times that on this nearby Astronomy Town–hotels, housing, a vineyard, a museum, a playground, classy restaurants, all those themed light fixtures. The government hopes that promoting their scope in this way will encourage tourists and new residents to gravitate to the historically poor Guizhou province.

It is, in a certain sense, an experiment into whether this type of science and economic growth can coexist. Which is strange, because ordinarily, they purposefully don’t.

The point of radio telescopes is to sense radio waves from space–gas clouds, galaxies, quasars. By the time those celestial objects’ emissions reach Earth, they’ve dimmed to near-nothingness, so astronomers construct these gigantic dishes to pick up the faint signals. But their size stimulates them particularly sensitive to all radio wave, including those from cell phone, satellites, radar systems, spark plugs, microwaves, Wi-Fi, short circuits, and basically anything else that uses electricity or communicates. Protection against radio-frequency interference, or RFI, is why scientists put their radio telescopes in remote locations: the mountains of West Virginia, the deserts of Chile, the way-outback of Australia.

FAST’s site used to be remote like that. The country even forcibly relocated thousands of villagers who lived nearby, so their modern trappings wouldn’t interfere with the new prized instrument.

But then, paradoxically, the government built–just a few miles from the displaced villagers’ demolished houses–this astronomy town. It also plans to increase the permanent population by hundreds of thousands. That’s a lot of cell phones, each of which persistently emits radio waves with around 1 watt of power.

By the time certain deep-space emissions reach Earth, their power often comes with 24 + zeroes in front: 0.0000000000 00000000000 0001 watts.

FAST has been in the making for a long time. In the early 2000 s, China angled to host the Square Kilometre Array, a collection of coordinated radio antennae whose dishes would be scattered over thousands of miles. But in 2006, the international SKA committee dismissed China, and then chose to set up its distributed mondo-telescope in South africans and Australia instead.

Undeterred, Chinese astronomers set out to build their own powerful instrument.

In 2007, China’s National Development and Reform Commission allocated $90 million for the project, with $90 million more streaming in from other agencies. Four year later, construction began in one of China’s poorest regions, in the karst mounds of the southwestern part of the country. They do things fast in China: The team finished the telescope in merely five years. In September 2016, FAST received its “first light, ” from a pulsar 1,351 light-years away, during its official opening.

A year later, Stierwalt and the other visiting scientists arrived in Pingtang, and after an evening of touring Astronomy Town, they got down to business.

See, FAST’s opening had been more ceremony than science( the commissioning phase is officially scheduled to end by September 2019 ). It was still far from fully operational–engineers are still trying to perfect, for instance, the motors that push and pull its surface into shape, allowing it to point and concentrate correctly. And the relatively new crop of radio astronomers running the telescope were hungry for advice about how to run such a massive research instrument.

The visiting astronomers had worked with telescopes that have contributed to understanding of hydrogen emissions, pulsars, powerful bursts, and remote galaxies. But they weren’t just subject experts: Many were logistical wizards, having worked on multiple instruments and large surveys, and with substantial and dispersed squads. Stierwalt studies interacting dwarf galaxies, and while she’s a staff scientist at Caltech/ IPAC, she use telescopes all over. “Each dedicates a different piece of the puzzle, ” she says. Optical telescopes depict the stars. Infrared instruments expose dust and older superstars. X-ray observatories pick out black hole. And single-dish radio telescopes like FAST ensure the bigger picture: They can map out the gas inside of and surrounding galaxies.

So at the Radio Astronomy Conference, Stierwalt and the other visitors shared how FAST could benefit from their instruments, and vice versa, and talked about how to run big projects. That work had begun even before the participants arrived. “Prior to the meeting, I traveled extensively all over the world to personally meet with the leaders of previous large surveys, ” says Marko Krco, a research fellow who’s been working for the Chinese Academy of Sciences since the summer of 2016.

He asked the meeting’s speakers, some of those same leaders, to talk about what had gone wrong in their own surveys, and how the interpersonal aim had functioned. “How did you organize yourselves? ” he says. “How did you work together? How did you communicate? ”

That kind of feedback would be especially important for FAST to accomplish one of its first, appropriately lofty objectives: helping astronomers collect signals from many sides of the universe, all at once. They &# x27 ;d call it the Commensal Radio Astronomy FAST Survey, or CRAFTS.

Above the dish, engineers have suspended instruments that collect cosmic radio waves .
Feature China/ Barcroft Media/ Getty Images

Most radio astronomical surveys have a single undertaking: Map gas. Find pulsars. Discover galaxies. They do that by collecting signals in a receiver suspended over the dish of a radio telescope, engineered to capture a certain range of frequencies from the cosmos. Normally, the different astronomer factions don’t use that receiver at the same time, because they each take their data differently. But CRAFTS aims to be the first survey that simultaneously collects data for such a broad spectrum of scientists–without having to pause to reconfigure its single receiver.

CRAFTS has a receiver that looks for signals from 1.04 gigahertz to 1.45 gigahertz, about 10 times higher than your FM radio. Within that range, as part of CRAFTS, scientists could simultaneously look for gas inside and beyond the galaxy, scan for pulsars, watch for mysterious “fast radio bursts, ” induce detailed maps, and maybe even search for ET. “That sounds straightforward, ” says Stierwalt. “Point the telescope. Collect the data. Mine the data.”

Engineers from FAST and the Australian science agency install the telescope’s CRAFTS receiver .
Marko Krco