Nine Hundred Telescopes and One Chance a Year

Reading the atmosphere of another world means catching starlight as it filters through that planet's air during a transit. The signal is about one part in a million and a true Earth twin transits only once a year, so you cannot simply repeat the measurement until the noise averages away. Each attempt has to work on its own. A team led from Shanghai has proposed the alternative to building an impossibly large mirror in space - nine hundred, one metre telescopes, flying together, watching the same transit and analysing the light together.