Astronomers and engineers of 17 nations are out to build the world’s biggest telescope, called the Square Kilometre Array (SKA), a huge radio telescope—composed of hundreds of small collection stations forming one ‘big picture’—covering the agreed frequencies of between 0.1 and 25 GHz. It will house 8,000 antenna and discs occupying a surface area of 50,000 square metres.
The SKA would be 100 times more powerful than any existing radio telescope. This ambitious project is slated to take off after the selection of the site in 2008. The entire project will be completed by 2020.
The 8,000 antenna would constitute an array of 3,000 kilometers with the goal of tapping bio-signatures existing in the Universe, outside our planet.
Two astronomers, Cocconi and Morrison, suggested in 1959 that a preferred frequency for extra terrestrial intelligence (SETI) could be the 1421 MHz (wavelength of 21 cm)—a natural line frequency emission of neutral hydrogen. The proposed SKA will enable scientists to tap SETI. There are technical reasons for searches to be carried out in the frequency range of about 1,000 to 10,000 MHz—the so called "water hole"—the frequency range of line emission in the universe from hydrogen and water, the building blocks of life.