Extra-terrestrial life is ‘inevitable’

Astronomers are standing on a "great threshold" of space exploration that could see evidence of extra-terrestrial life being discovered in the next 20 years, an expert has claimed.

Life beyond the Earth seems “inevitable” given the immensity of the universe, according to US planetary scientist Dr Sara Seager.

Chemical fingerprints of life in the atmospheres of planets could be found by super space telescopes.

Writing in the journal Proceedings of the National Academy of Sciences, Dr Seager, from the Massachusetts Institute of Technology (MIT), said: “We can say with certainty that, for the first time in human history, we are finally on the verge of being able to search for signs of life beyond our Solar System around the nearest hundreds of stars.”

Astronomers now know that statistically, every star in our galaxy, the Milky Way, should have at least one planet, and small rocky worlds like the Earth are common.

“Our own galaxy has 100bn stars and our universe has upwards of 100bn galaxies — making the chance for life elsewhere seem inevitable based on sheer probability,” said Dr Seager.

In the next decade or two, a handful of “potentially habitable” exoplanets will have been found with atmospheres that can be studied in detail by sophisticated space telescopes.

The first of these “next generation” telescopes will be the American space agency Nasa’s James Webb Space Telescope (JWST) due to be launched in 2018. It will be able to analyse the atmospheres of dozens of “super-Earths,” rocky planets larger than Earth, including several that could harbour life.