The European Space Agency will launch an observatory into space designed to seek out potentially habitable planets outside of our solar system. The PLATO (Planetary Transits and Oscillations of stars) mission will search for planets by monitoring the brightness of up to a million nearby stars. The space-based observatory will use 34 separate small telescopes and cameras to watch for tiny, regular drops in their targets’ brightness: a sign that a planet is passing in front of the star.

A space-based observatory to search for planets orbiting alien stars has been selected today as ESA’s third medium-class science mission. It is planned for launch by 2024. The PLATO – Planetary Transits and Oscillations of stars – mission was selected by ESA’s Science Programme Committee for implementation as part of its Cosmic Vision 2015–25 Programme. The mission will address two key themes of Cosmic Vision: what are the conditions for planet formation and the emergence of life, and how does the Solar System work? PLATO will monitor relatively nearby stars, searching for tiny, regular dips in brightness as their planets transit in front of them, temporarily blocking out a small fraction of the starlight.