World’s largest tele­scope be­gins peer­ing into space

Dish as big as 30 soc­cer fields, in Guizhou, to push Chi­nese sci­ence to fore­front

China Daily (USA) - - FRONT PAGE - By HOULIQIANG and YANG JUN in Ping­tang, Guizhou

Sci­en­tists of the world, at­ten­tion please: You are in­vited by China to lis­ten for alien life from the world’s largest tele­scope it built.

With the mas­sive fa­cil­ity of­fi­cially begin­ning to op­er­ate on Sun­day, lead­ing sci­en­tists told China Daily that for­eign sci­en­tists will be wel­come to use China’s gi­gan­tic Five-hun­dred-me­ter Aper­ture Spher­i­cal Tele­scope, known as FAST.

It is a sin­gle-aper­ture tele­scope the size of 30 soc­cer fields, lo­cated in Guizhou prov­ince in south­west­ern China.

The fa­cil­ity, sur­pass­ing the sec­ond­largest by 200 me­ters in di­am­e­ter, is be­ing called a game-changer in space re­search.

Pres­i­dent Xi Jin­ping on Sun­day sent a con­grat­u­la­tory let­ter to the sci­en­tists and en­gi­neers who con­trib­uted to its cre­ation.

“The launch of FAST sym­bol­izes a ma­jor break­through in China’s sci­ence re­search and has great sig­nif­i­cance for the coun­try’s strat­egy to push for­ward in­no­va­tion,” Xi said in the let­ter.

FAST will search for grav­i­ta­tional waves, de­tect ra­dio emis­sions from stars and gal­ax­ies, and lis­ten for signs of in­tel­li­gent ex­trater­res­trial life, sci­en­tists said.

“The ul­ti­mate goal of FAST is to dis­cover the laws of the de­vel­op­ment of the uni­verse,” said Qian Lei, an as­so­ciate re­searcher with the Na­tional As­tro­nom­i­cal Ob­ser­va­tion, part of the Chi­nese Academy of Sci­ences, which built the tele­scope.

“In the­ory, if there is civ­i­liza­tion in

outer space, the ra­dio sig­nal it sends will be sim­i­lar to the sig­nal we can re­ceive when a ra­di­a­tion beam from a pul­sar (spin­ning neu­tron star) is ap­proach­ing us,” Qian said.

Zhang Shuxin, deputy gen­eral man­ager of the project, said for­eign sci­en­tists can start con­duct­ing their own space re­search at FAST once de­bug­ging is com­pleted.

But be­fore that is done, “we wouldn’t feel very good” to start dis­tribut­ing time slots to for­eign as­tronomers, he said.

“It’s such a huge thing, you see,” Zhang said. “And the tech­nolo­gies we use in both its driv­ing de­vice and re­flect­ing sur­face are en­tirely new to us.”

“As the first step, a par­a­bola of 300 me­ters in di­am­e­ter will be formed on the sur­face, with the help of the driv­ing de­vice, and start re­ceiv­ing sig­nals,” he ex­plained. “We need to gather ex­pe­ri­ence and de­velop method­ol­ogy to en­sure de­tec­tion ac­cu­racy for that.”

It may be three to five years be­fore FAST can guar­an­tee its best per­for­mance, Zhang said.

FAST’s large hemi­spheric sur­face is made up of 4,450 1.3-mil­lime­ter-thin re­flect­ing pan­els, each weigh­ing 427 to 482.5 kilo­grams. The first panel was in­stalled in Au­gust 2015. Patch­ing all the pan­els to­gether took 11 months.

Sun Cai­hong, deputy chief en­gi­neer for FAST, said the tele­scope’s op­er­a­tors will fo­cus on strong ra­dio sources al­ready known to them. He said sci­en­tists are also ex­pect­ing to make some progress in re­search by an­a­lyz­ing data they re­ceive in the de­bug­ging.

Wang Qim­ing, chief en­gi­neer for FAST, said: “We would like to fin­ish de­bug­ging quickly. FAST will be the world leader in 10 to 20 years. We would like tomake full use of this pe­riod.”

FAST al­ready had a good start, sci­en­tists said. In a re­cent test, it re­ceived a set of high-qual­ity elec­tro­mag­netic waves sent from a pul­sar about 1,351 light-years away.

It was the best-qual­ity sig­nal that FAST had re­ceived since it started its trial ob­ser- va­tion in mid-Septem­ber.

Wang said the most chal­leng­ing part of de­bug­ging is ad­just­ing the laser that per­forms mea­sur­ing tasks on the re­flect­ing sur­face. As long as the laser mea­sur­ing de­vice de­tects er­rors in a timely way, sci­en­tists can make im­me­di­ate ad­just­ments.

The tele­scope is lo­cated in an al­most-per­fect spher­i­cal land­form, so there was no need to dig a hol­low for it. The val­ley in Guizhou was cho­sen also for its karst land­form, which en­sures good drainage, mean­ing rain­wa­ter won’t gather and dam­age the re­flect­ing sur­face of the tele­scope.

Philip Di­a­mond, di­rec­tor­gen­eral of Square Kilo­me­ter Ar­ray, a large mul­ti­ra­dio tele­scope project, said: “FAST is the big­gest sin­gle dish in the world. It will have new tech­nol­ogy, and a new re­ceiver sys­tem, to be much more ef­fi­cient. As­tronomers and sci­en­tists are queu­ing up all around the word to use it.”

Di­a­mond said the SKA, an in­ter­na­tional project in which China is a mem­ber, will be even larger than FAST.

“But ours won’t be in the form of one sin­gle dish. It will be hundreds and thou­sands of smaller dishes spread over a large area. They will work to­gether,” he said.

“You can think of FAST as a wide-an­gle lens and the SKA as a zoom lens. FAST will find a lot of ob­jects, and SKA will of­fer a lot of de­tails on th­ese ob­jects. They will be very com­ple­men­tary.”

An­thony Beasley, di­rec­tor of Na­tional Ra­dio As­tron­omy Ob­ser­va­tory of the United States, said there are many ar­eas of ra­dio as­tron­omy in which FAST will bring Chi­nese as­tronomers to the fore.

Beasley said it likely will be two to three years, while the tele­scope is brought to its full strength, be­fore they use it.

Con­struc­tion of the nearly 1.2 bil­lion yuan ($180 mil­lion) FAST project started in 2011, 17 years af­ter it was pro­posed by Chi­nese as­tronomers.

HE JUNYI / FOR CHINA DAILY

Bowl-shaped val­ley be­comes space-age won­der in th­ese start-to-fin­ish photos show­ing the con­struc­tion of the world’s largest tele­scope in Guizhou prov­ince.

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