It was recently announced that the world’s largest radio telescope, built by Chinese scientists, had started its first observations. Its dish is a colossal 500 metres in diameter, dwarfing its nearest counterpart, the Arecibo telescope which has a diameter of 305 metres. Like the Arecibo radio telescope, which is operated by a group which includes the US National Science Foundation, this Chinese telescope is built in a crater. This means that both telescopes are not actually steerable, so observations can only be made of objects which pass within a few tens of degrees of the zenith (directly overhead). The largest steerable telescope remains the 76-metre Lovell telescope run by the University of Manchester [Correction : the largest steerable telescope is the 100-metre Effelsberg telescope In Germany. In fact, the re-built Green Bank telescope in West Virginia is also larger than the Lovell telescope. Thank you Phillip for pointing out my mistake.]
Officially known as the Five hundred metre Aperture Spherical Telescope (FAST), this new facility is located in the Guizhou province in southern China.
Like many areas in science, China is making great strides in its observational astronomy capabilities. It has already bought partnerships in a number of the world’s largest visible-light and sub-millimetre telescopes, but this marks its first home-grown world-beating facility. The telescope took five years to build and cost about 180 million US dollars. It will take a few years of testing before it can reach its full scientific potential, but when it does it will be an exciting addition to the world-wide arsenal of current and planned radio telescopes.