Giant telescope could hunt for oxygen on exoplanets

New Scientist : One way of looking for life on other planets is to detect the presence of oxygen, because plants and bacteria are among the only sources of atmospheric oxygen, at least on Earth. However, current ground-based telescopes are not sensitive enough to detect oxygen, and space missions that could have searched for it have been cancelled. However, according to a new study , scientists may be able to use the European Extremely Large Telescope , now being built in Chile. With its 39-m mirror and extremely high resolution, the telescope will be able to image some of the most distant stars and galaxies in the universe. Then it’s a matter of patience: An exoplanet has to travel past its star repeatedly before the presence of oxygen can be determined, and that process can take a few years or hundreds. Merely detecting oxygen is not enough, though; further observations would be needed to confirm the presence of life.