ESA PLATO Exoplanet Mission

ESA's PLATO mission — Planetary Transits and Oscillations of stars — is scheduled to launch in December 2026 aboard an Ariane 6 rocket, bound for the Sun-Earth L2 Lagrange point approximately 1.5 million kilometres from Earth. PLATO is distinguished by its unprecedented multi-telescope architecture: 26 cameras arranged in four overlapping groups observe simultaneously, providing photometric precision at a field-of-view scale that no single large telescope can achieve. This configuration allows PLATO to monitor more than 200,000 stars continuously, searching for the telltale brightness dips of transiting exoplanets. PLATO's primary science goal goes beyond simple planet detection. By simultaneously measuring stellar oscillations — the natural acoustic modes that make stars ring like bells — PLATO can determine the ages and masses of host stars with unprecedentedly high precision. This enables accurate characterisation of exoplanet radii, densities, and ultimately habitability assessments that previous missions like Kepler and TESS could not achieve. The mission specifically targets Earth-sized planets in the habitable zones of Sun-like stars, the category most likely to host environments compatible with life as we understand it. PLATO has a spacecraft mass of approximately 2,300 kilograms and a deployed solar panel wingspan of around 9 metres. The 26 cameras are divided into 24 normal cameras (each with a 1-degree field of view) and 2 fast cameras (used for bright stars requiring rapid readout). ESA estimates that PLATO will discover hundreds to thousands of exoplanets over its nominal 4-year mission, including dozens of Earth-sized planets in habitable zones. The mission represents Europe's flagship contribution to exoplanet science for the 2030s, complementing NASA's Nancy Grace Roman Space Telescope and the James Webb Space Telescope's atmospheric characterisation capabilities.