The search for signs of extraterrestrial life looks set to be one of the most exciting scientific endeavours of the 21st century and scientists have no shortage of places to look. Astronomers have already discovered nearly 2000 exoplanets and they look set to find many more. While most of these known exoplanets are gas giants that appear to be inhospitable to life, the discovery of Earth-like rocky exoplanets could come courtesy of the next generation of telescopes.

In this podcast recorded at the Canadian Association of Physicists Congress in Edmonton, Sara Seager tells physicsworld.com editor Hamish Johnston how astronomers are gearing up to use the James Webb Space Telescope – due to launch in 2018 – and other ground- and space-based facilities to look for water vapour, oxygen and other gases in the atmospheres of rocky exoplanets. These and other gases such as methane could indicate the presence of life on these distant worlds, but Seager points out that many measurements on many different exoplanets will be needed before we can say with reasonable certainty that life exists.