The world's largest radio telescope started its operation in south-western China on Sunday, which the scientists believe will help humanity to search for alien life.

Xinhua, the official news agency reported that the Five-hundred-metre Aperture Spherical Radio Telescope (FAST) began operating around noon. It is situated between the hills in the mountainous region of Guizhou.

The telescope built at a cost of 1.2 billion yuan (S$245 million) dwarfs the next biggest dish, Arecibo Observatory in Puerto Rico as the world's largest radio telescope.

FAST is made up of 4,450 triangular panels and it has a reflector as large as 30 football fields. The telescope will explore space and search for signs of intelligent life.

The telescope will study the distribution of neutral hydrogen and seek to unlock answers on the evolution of the universe. It will also compile huge amounts of data on physical phenomena in space, such as pulsars and black holes.

China sees its multi-billion-dollar space programme as a symbol of the nation's progress. Beijing also plans to build a permanent orbiting space station by 2020 and eventually a manned mission to the moon.

"The telescope's high degree of sensitivity "will help us to search for intelligent life outside of the galaxy," Wu Xiangping, director-general of the Chinese Astronomical Society told Xinhua.

It has taken more than two decades for FAST to become a reality. The project was first raised in 1993 but it took years for the scientists to settle on an appropriate site. The project finally started in 2011.

In February the local officials assured to relocate nearly 10,000 people living within 5 km as they wanted to create a better environment for monitoring.

This was nothing new as in the past China has relocated hundreds of thousands of people to make space for large infrastructure projects like dams and canals.

The area which is surrounding FAST is remote and relatively poor. Earlier Xinhua reported that the area was selected for the project as there are no major towns nearby the area.