After looking at that gigantic dish you might think that what on this earth it is going to be used for. Certain questions would arise in your mind, like, is that a giant bowl for storing water? Why on this earth somebody would waste his energy for building a bowl like that? Does it has to do anything with the Guinness record?
If you think that it is some kind of bowl build to feed a whole country and solve its utensils crises, then I am sorry you are wrong. This humongous dish is a radio telescope having 500-meter aperture and covering an area of about 70,000 sq. meters (worlds biggest). I know what is rumbling in your mind. Holy Ghost on a bicycle, isn’t it.
Well, the credit for creating this gigantic dish goes to (drumroll please) none other than china, a country well known for presenting the techy stuff to the world every time. They have named this project as tiyanyan (means the ‘’eye of heaven’’ in Chinese). People around the globe are calling it as F.A.S.T (Five-hundred-meter Aperture Spherical Telescope) and maybe that’s why it’s popular nowadays on every news channel.
Here comes the big question, what is F.A.S.T actually?
F.A.S.T is nothing but a radio telescope built to explore the beauty of the cosmos and reveal what it says. Like other telescope’s it would be the eye of the Chinese scientists to see the world beyond our sky. It would be used for their scientific research programs.
How does it work?
F.A.S.T has a fixed primary reflector which is located in a natural hollow in the landscape (karst), focusing radio waves on a receiver which is suspended 140 m (460 ft.) above it. The reflector is made of perforated aluminum panels supported by a large number of steel cables hanging from the rim.
F.A.S.T has a surface made up of 4450 triangular panels, 11 m (36 ft.) on a side, in the shape of a geodesic dome. Actuators underneath it make it an active surface which pulls and pushes on joints between panels and deforms the flexible steel cable support into a parabolic antenna aligned with the sky direction desired by the astronomers.
Above the reflector is a light-weight feed cabin which is moved by a cable robot using winch servomechanisms. The receiving antennas are mounted below it on a platform which compensates for disturbances like wind motion and earthquakes and also provides fine position control. This produces a well-planned pointing precision of 8 arc seconds.
Although the reflector diameter is about 500 meters (i.e. 1,600 ft.), only a circle of about 300 m diameter is used at any one time.
Its working frequency range of about 70 MHz to 3.0 GHz, which is covered by 9 receivers, with the band around the hydrogen line (1.23–1.53 GHz)using a 19-beam receiver built by collaboration between the great Australian Academy of Science and the Chinese Academy of Sciences. Hope this Chinese product would last long.
Don’t be upset
We in India also have a radio telescope that works approximately the same as F.A.S.T does. It’s called as G.M.R.T (Giant Metrewave Radio Telescope) and one of the aims for this telescope during its development was to search for the redshifted radiation (21 cm length) from the primordial neutral hydrogen cloud in order to determine the epoch of galaxy formation in the universe.
I know, that might have gone over your head and therefore in English, it means that astronomers regularly use this telescope to observe many different astronomical objects which form the cosmos such as galaxies, supernova, the Sun, black holes etc.