![This artist's impression shows what the TRAPPIST-1 planetary system may look like.](/content/dam/images/g/u/k/i/e/3/image.related.afrArticleLead.620x350.gukgec.png/1487925791137.jpg)
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If there is life on the seven earth-sized planets discovered in our galaxy, a next-generation telescope soon to be built in Western Australia is one of science's best chances of finding it.
Australian astronomers are already working on the search for extra-terrestrial existence from the Parkes radio telescope in NSW which, along with two new telescopes in Western Australia, has the capability to detect signals of intelligent life by collecting and analysing radio waves.
"We emit radio waves that could travel across a fraction of the galaxy and so if we make the assumption that other civilisations are like us then looking for radio waves is a very sensible thing to do," says CSIRO director of astronomy and space science Douglas Bock.
"The things on earth that you might be able to see from nearby stars are airport radars or radio antennas or even radar signals. Perhaps they have signals like that."
![An artist's concept of the TRAPPIST-1 star, an ultra-cool dwarf, with its seven Earth-size planets orbiting it.](/content/dam/images/g/u/k/i/d/j/image.imgtype.afrArticleInline.620x0.png/1487901093158.jpg)
NASA announced on Thursday that a single star just 40 light years away is home to seven Earth-like planets, many of which could host life, together named the TRAPPIST-1 system.
Three of these planets are firmly within what is called the 'Goldilocks Zone' – the zone around a star where a planet is most likely to have liquid water, a necessity for life.
The discovery, published in the journal Nature, sets a record for the largest number of potentially habitable worlds found around a single star outside our solar system.
It is expected to take a few years for scientists to determine what the conditions are like on the surface of the planets, by which time the world's most powerful radio telescope will be nearing-completion and preparing to probe the depths of the universe.
The multibillion-dollar Square Kilometre Array telescope will consist of hundreds of thousands of antennas spread across Western Australia and South Africa which together will be ten times more powerful than today's best radio astronomy facilities. Construction of the SKA is targeted to start in late 2018 with operations beginning in 2021.
![Take a planet-hopping excursion through the TRAPPIST-1 system, some 40 light-years from Earth.](/content/dam/images/g/u/k/i/e/4/image.imgtype.afrArticleInline.620x0.png/1487901348487.jpg)
"The real fundamental mission of the telescope is to survey the sky to a depth and detail that has never been done before and that is exactly where you will start seeing these kinds of situations where you might see a stellar system with a strong radio emission and you have to investigate why and that would be extremely exciting," International Centre for Radio Astronomy Research executive director Professor Peter Quinn said.
CSIRO's Parkes telescope has been participating in the $US100 million Breakthrough Listen search for intelligent life, launched in 2015 by Stephen Hawking and entrepreneur Yuri Milner, since November.
While Parkes was not involved in defining the TRAPPIST-1 system, its location presents an obvious target for Parkes's search for ET.
"If there should be anyone out there talking to us they are going to be talking, we think, from planets like this," Dr Bock said.