China Building Huge 500-Meter Radio Telescope

Article written: 31 Jan , 2009
Updated: 24 Dec , 2015


Official ground-breaking ceremonies took place for a gigantic new 500 meter diameter radio telescope in China which will allow astronomers to detect galaxies and pulsars at unprecedented distances. The $102 million facility, known as the Five-hundred-meter Aperture Spherical Telescope (FAST), will have a collecting area more than twice as big as the 305 meter diameter radio telescope at Arecibo Observatory in Puerto Rico, which has been the world’s largest since it opened in 1964. Not only that, the new telescope will also have the ability to change its shape and move the position its focus.

Like the Arecibo telescope, the new telescope will sit in a natural depression that already is close to the shape of the collecting surface, simplifying the support structure and shielding the telescope from stray human-generated radio waves. The location is quite remote, about 170 km by road from the Guizhou Province’s provincial capital Guiyang, making it unusually radio-quiet, says Nan Rendong, FAST chief scientist and a researcher from the National Astronomical Observatories at the Chinese Academy of Sciences, in an article in

The site’s potential for long, uninterrupted observations — coupled with the telescope’s huge size, which will give it twice the sensitivity of Arecibo — means that researchers there will be able to detect objects like weak, fast-period pulsars that are too faint to be measured accurately by smaller instruments.

Groundbreaking ceremonies for FAST. Credit:

Groundbreaking ceremonies for FAST. Credit:

“The FAST science impact on astronomy will be extraordinary,” Nan said, adding that although the telescope is located in China, once it is completed in 2014 it will be open to astronomers from around the world.

A system of motors attached to its 4600 panels will allow astronomers to change its shape from a sphere to a paraboloid, making it easier to move the position of the telescope’s focus. This will allow the south-pointing telescope to cover a broad swathe of the sky — up to 40 degrees from its zenith, compared to the 20-degree-wide strip covered by Arecibo.

At first, however, the telescope will only be sensitive to low-frequency radio waves, less than 3 GHz. Arecibo’s bandwidth, by contrast, stretches up to 10 GHz.

A planned second phase of construction will extend FAST’s range to 5 GHz, but a date for the upgrade has not yet been set.


37 Responses

  1. Theta says

    This is very interesting. This FAST combined with new optical telescopes such as the European Extremely Large Telescope will hopefully usher in a new era of astronomy! 🙂

  2. Nasikabatrachus says

    Thanks for the information, Peter Backus.

  3. Salacious B. Crumb says

    The Chinese are certainly becoming the technological trend-setters of the world when it comes to radio astronomy. Guizhou Province is probably the best place to put any radio telescope (expect perhaps western and central Australia, but the geography has few valleys large enough to hold such a telescope.) Sadly, nowhere in the U.S. would a radio telescope like this be abled to be placed because of the radio static. I guess the Moon might become the only option…
    FAST will likely set the trend of radio astronomy well into the mid 21st Century! Go China!

  4. Spoodle58 says

    Its nice to see other nations on this planet kicking ass in the science’s.

    Go China!

  5. Sili says

    Awesome! I’m glad to hear of a new Arecibo – more, more!

    But … just what would a small 500-meter telescope look like?

  6. Dee says

    Fantastic – well done China! The next decade is going to be really amazing with all the new space and terrestrial telescopes coming into use. I can’t wait for JWST – it’s OK – I still love Hubble!

    Sili – thanks for that question – I’m still giggling! 😀

  7. tacitus says

    Excellent, though one wonders why they didn’t just call the thing the “Five-hundred-meter Aperture Radio Telescope” (FA…) …. oh…. I see.

  8. Nasikabatrachus says

    It would be interesting to read a comparison of FAST’s potential capabilities and the Allen array, Arecibo, and very-long baseline multi-telescope projects.

  9. Answering Nasikabatrachus:

    The Allen Telescope Array will have a sensitivity equivalent to a single 114 meter dish, the resolution of a 900 meter dish, and the wide field of view (the area of sky that can be studied that can be studied at one time) of a 6 meter dish. These features make it ideal for large survey projects.

    The VLA and VLBI projects have sensitivity similar to the ATA but much better angular resolution.

    Large dishes like Arecibo and FAST excel in sensitivity.

  10. Zhai Ao Ning says

    Much happiness to hear of this China telescope. Thank you to say this.

  11. Conic says

    Why not make a 500 meter optical telescope?

  12. robby says

    Conic-I’m sure that’s on the wish list of all Astronomers and Scientists-with todays technology it can be done using multi-mirror-
    computer controlled systems. The problem is the COSTt-it would be enormous! It would require thousands of mirrors, each mirror must be sligtly different and will entail high labor cost.Perhaps later, with much cheaper materials and automated mirror making, the cost will lower.

  13. robby says

    Great- when completed will contribute greatly to understanding many unknowns of the conponents of our universe

  14. Feenixx says

    Apart from being an amazing science instrument, looking at some other large works of Chinese architecture and engineering, it’ll probably also be a True Thing Of Beauty!

    I’d like to go there when it’s finished, and shoot a movie of it.

    Sili says:
    “But … just what would a small 500-meter telescope look like?”
    Yours truly wonders: Do they actually have small meters (or metres) in China, for building such a project?

  15. Nicole says

    I’ve seen concept designs for the Square Kilometer Array in its earlier days that was an array of those things.

  16. I see more intrinsic redshifts and discordant redshift associations coming as a result of this.

  17. Flaming Pope says

    @ Conic: The hubble tele is up already.

    But yea Woo Hoo! Go China, go China yeaaaah, yeaaahhh!

    What an awesome mass scale government experiment of communism. This is communism at its best (as apposed to USSR). I guess the leader of China is a good guy at heart after all- at least towards science.

    Now then… lets do it better in America. Lets show them America is better at science than any communist state corrupted or its peak. They have radio tele and fusion parts, Europe has the collider, Singapore with bio tech, Japan is machine tech – What have we got to show these days? – dusty fission, oil companies>>failed solar/hydrogen, inefficient biofuels(wastes energy to make), material science (minor plus), points is, SHOW US THE SCIENCE!

  18. Simon says

    ahh but the americans have beaten the chinese in sausage making

  19. Conic says

    Flaming pope the hubble mirror is 2.4 meters.

    I asked why not make a 500 meter (that is to say, 200 times larger diameter) optical telescope?

  20. pmf71 says

    Conic: An optical scope that big would cost close to $ 1 Trillion. Ok maybe 500 billion, nevertheless…too costly to build.

  21. robby says

    Conic-I wish they will make such a telescope, but the weight of todays materials, the enormous size-I would say the base and platform will have to be of great strength and size to drive such a telescope-think of something like the size of the pier for the Golden Gate Bridge in San Francisco or other large structures. Perhaps later, with improved technology, much lighter materials for the mirrors and aiming devices, such a large dream telescope can be made within the budget of a consortium of Universities and other Scientific firms.

  22. pterzw says

    Shopped. Pixels are all wrong. I have seen many photoshopped pics so I can tell.

  23. Tony Trenton says

    So what?

    Have some patience

    Wait & see what really takes place

    That is what will really matters

  24. Simon says

    aww, no one picked up on my historical reference

  25. Richard Kirk says

    There are ESO plans for a 100m optical telescope. The estimated cost is eur 1.2 billion. Presumably this would go up a bit of they stuck it on the Antarctica dome, where you would get the best viewing. See…

    If this was built (and it has been on the drawing board for some time, but it isn’t silly engineering) it would probably stay the largest telescope on earth, because larger ones (500m) would probably have to be made in space.

  26. robby says

    Nicole, I remember reading about the array of super size radio-telescopes in a science magazie 30-35 years ago, and was to be located in New Mexico or high plateau area. The concept picture was interesting and was to cover a 150mile diameter field. The author was being quite resonable when such a array would be build-about the year 2400-he said there would be 50 build around the world to track manned spacecraft traveling outside the solar system. It was just a short article.Now, I have to stop to get back to my relatives about the Super Bowl lol

  27. Astrofiend says

    # Conic Says:
    January 31st, 2009 at 5:34 pm

    Flaming pope the hubble mirror is 2.4 meters.

    I asked why not make a 500 meter (that is to say, 200 times larger diameter) optical telescope?

    >>> Conic – a telescope’s capability is limited by the accuracy of it’s primary optic’s figure. The accuracy required of the figure is determined by the wavelength of the radiation you wish to reflect and bring to a focus – the accuracy required is crucial to allow the optics to be able to form an image with the incoming electromagnetic radiation of the object under study. Typically, you need the surface of the mirror (or other reflecting surface) to deviate from the perfect mathematical shape by no more than 1/8 of the wavelength of the radiation to be focused.

    Now, radio waves have wavelengths ranging from cm to km’s in length. So a radio reflecting dish would have to be accurately figured to within a couple of mm – i.e. over it’s entire surface, no part of it deviates from a perfect paraboloid by more than 1 or 2 mm. This is within reach of today’s engineering capability for a 500 m radio dish.

    Optical radiation has a far shorter wavelength – about 400 – 800 nm, or 4 – 8 ten-millionths of a meter. Hence, to get a surface that will act properly as a reflector for a telescope, it needs to be perfectly figured to at least 1/8th of that number or about 50 billionths of a meter, over it’s entire surface. So if we were to try to fashion a 500 m primary mirror, it would have to be so accurate that if we were to blow it up in our minds to the width of Australia, the largest surface deviation would be on the order of a millimeter or so from perfect. Also note that the ‘1/8 of the wavelength’ criterion is the bare minimum – professional telescopes should be (and are) figured to much higher accuracy and precision than that. This is extremely difficult to do, and to date, such accuracies have been achieved with mirrors up to about 10 m in diameter.

    But that’s not the real killer – large mirrors can be made to be that accurate by using multiple segments, and there is no reason that such technology can’t continue to be pushed out. The thing is, the rest of the structure must be proportionately accurate too – and remain so under the stresses and strains of gravity etc. Radio telescopes can be built so big because with clever engineering, the structures that hold the detectors over the dish can be made to flex only minutely – small enough not to stuff up the observations. Even a tiny tiny tiny amount of flexure in an optical telescope’ structure though will ruin observations – defocus images, warp the image planes etc etc..

    Essentially, such telescopes are beyond our engineering capability because we can’t work out how to make their support structures rigid enough. For now…

    Oh, and there’s little matter that such beyond-the-frontiers engineering would cost a bomb of cash.

  28. robby says

    Astrofiend -1/2 time with relatives.I retired 2 years ago as a Network Administrator at 55yo-so I have no true knowledge of engineering, but the base or ‘pedestal’ -take the base of the Golden Gate Bridge tower and for the ‘leg’ in order to aim the scope to about 30 degrees above the horizon- would have to be about 80-85% of the radius of the 500 meter scope-think the tower of the Golden Gate Bridge!!! However, because of the enormous weight of the scope- the ‘leg’ would have to be far more robust than the tower of the Golden Gate Bridge. Then theres the protecting building to protect to scope from the elements=a large building.
    The project would require far more than building the largest bridges in the world.
    Forget about it for now as the price is going to be enormous !

  29. Astrofiend says

    robby Says:
    February 1st, 2009 at 6:33 pm

    Yep – There are many reasons such a project would be impractical if not impossible at the moment, and you’ve ably highlighted a couple more…

    It would be an impressive building though, eh…

  30. hiro says

    I think a 10 m space telescope orbits around 550 AU from the Sol should be very interesting. We can observe a lot of stuff outside our galaxy. If we can somehow build a big telescope in space ( let say 500 m ) and put it at a reasonable distance ( 600 AU ) from Sol, then …. I cant breath; this is too much!!!

  31. marcellus says

    I would like to see something like this built, but I’m not going to hold my breath until it actully happens.

    Good luck to the Chinese. I like their food, but my favorite Chinese restaurant in Dublin Georgia got shut down for serving dog and cat.

    I was bitterly disappointed.

  32. robby says

    hiro-I beieve a 10 meter is quite feasible, and will be a great replacement for the aging 2.4 meter HST. The 500 meter scope, although 50 times the diameter of the 10 meter scope, requires 2500 times more mirror space, scaling a scope up 50 times the diameter creats its own set of problems for which is far beyond my knowldege or eduation as I retired as a Network Administrator and just a serious amature astronomer.This dream project is centuries down the road. Next,
    Our current proplusion systems to launch so much material from the surface of the Earth for such a 500meter scope is beyond the budget of the 10 largest economic powers at this time. Still, it is quite a dream to think about-the potential!!

  33. robby says

    Marcellius-Ive read your last post on Global Warming and agree with you 100%, I just don’t want funds taken from our existing programs to feed that questionable organization. We have plenty of problems to fix and finding more problems that will eventually need fixing.
    To the feed, it will be a great contributor to science if the 500meter radio-scope is finished. Most people still can not comprehend the scale of the structure compared to existing structures. Take care

  34. Does anyone know where I can find free online grant applications?

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