As you might be able to tell from its real name, FAST is around 1,600 feet in diameter, while in terms of composition, it’s made up of almost 4,500 triangular panels with sides each measuring 36 feet. Meanwhile, a series of winches underneath the panels lets them move to have a better view of the sky. This means, mind you, that the telescope can only use three-fifths of its aperture at one time.
If you’re thinking that the telescope is the sort that you look through, though, you’d be wrong. You see, it’s what’s known as a radio telescope, which means that it scans the sky for the distinct radio-wave signatures of astronomical objects. As a result, it can be used in the daytime, unlike an optical telescope. And this also accounts for the size of FAST – as well as many of the problems that plagued its construction.
The building of the huge telescope began in 2011, but its history actually goes back a good deal further than that. The idea for FAST dates as far back as 1994, in fact, and it was subsequently commissioned in 2007. Constructing the massive piece of apparatus wasn’t without its controversy, either, mind you, and that’s partly down to its sheer size.