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The search for alien life in our infinite universe just got a fresh infusion of money and enthusiasm. Russian billionaire Yuri Milner has announced $100 million for a decade-long project called Breakthrough Listen to detect communications from extra terrestrial life forms, if they exist. The search for extra terrestrial intelligence has resulted in a big silence so far.

The only blip on the SETI radar has been a 72-second long signal sequence picked up by the Big Ear Observatory in Ohio in 1972. The signal, named the Wow! Signal after scientist Jerry R Ehman wrote the word ‘Wow!’ on a computer printout of the reading, seemed to come from the Sagittarius constellation. The Wow! Signal has never been picked up again.

India’s contribution to the SETI enterprise comes from one formidable radio telescope in Khobad near Pune. The Giant Metrewave Radio Telescope is the world’s largest radio telescope. A project pioneered by radio astronomer Govind Swarup, it as built during the 1990s and available for use by the international scientific community by 2002.

The GMRT is made up of 30 giant antennae arranged in a Y-shape spread over 25 kilometers. Each antennae is 45 meters in diameter and weighs about 80 tons. The antennae and fully steerable and can cover 80 percent of the sky visible from the earth.

As the GMRT antennae latch on to radio signals from across the cosmos zipping across the earth, the data is used to study stars, pulsars and hydrogen clouds. But the GMRT’s computers are also watching for whether any of the radio signals might be emitted from an intelligent non-terrestrial life form. This is done by checking whether the source of the signal is natural or artificial. The signal from a natural source will be intermittent. Artificial signals, constructed deliberately and emitted, will come in as steady pulses.

India is now collaborating in another ambitious SETI project – the Square Kilometer Array to be built in Australia and South Africa. The SKA is expected to improve detection of signals by more than two orders of magnitude of any existing telescope.

But how good an idea is SETI? The search is based on many assumptions – that there is intelligent extra-terrestrial life, that the life form at least as technologically advanced as humans to be able to communicate using radio waves, and that they are also reaching out across the universe for other life. So the question as most often by and of SETI astronomers is “What happens when we find alien life?”

Seth Shostak, astronomer at the Centre for SETI Research, writes in the SETI Institute’s blog,“If we find intelligent beings elsewhere in our galaxy, you'll not be quickly confronted with complex philosophical problems of understanding their mode of thinking or their biological blueprint — or even knowing whether they are biological. You won't be misled by anthropocentric thinking, because there will be precious little information about whether they're like us or not. For years, all we'll be able to say is that there's something out there that's at least as technologically competent as we are.”