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, says US planetary scientist Dr Sara Seager. In the coming decades chemical fingerprints of life written in the atmospheres of planets orbiting nearby stars could be found by the next generation of space telescopes. Writing in the journal Proceedings of the National Academy of Sciences, 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." via The Guardian.