Aerial view of the Five-hundred-meter Aperture Spherical radio Telescope (FAST), Guizhou Province of China © VCG/Getty Images

What is the biggest telescope on Earth?

Think FAST if you want to search in outer space.

Asked by: Isabelle Sanders, London

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The world’s largest radio telescope became fully operational in September this year. FAST, as the 500m-wide telescope is called, is located in Pingtang County in southwest China. A total of 4,450 panels make up the reflector, and suspended in the middle is the cabin, which will collect signals from space. FAST will gather data on pulsars, galaxies, black holes and signs of extraterrestrial life.

The biggest optical telescope in operation is the Gran Telescopio Canarias (GTC), with an aperture of 10.4 metres. There are larger optical telescopes in the pipeline though.


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