Gaia

Mission Profile

Gaia is an ESA astrometry satellite launched on 19 December 2013 aboard a Soyuz ST-B to the Sun-Earth L2 Lagrange point, designed to create the most precise three-dimensional map of the Milky Way galaxy ever assembled by measuring the positions, distances, motions, and properties of over one billion stars. Using two telescopes and a billion-pixel camera — the largest focal plane ever flown in space — Gaia measures star positions to microarcsecond precision, enabling determination of distances across thousands of light years. Successive Gaia data releases have revolutionized Galactic astronomy, enabling discoveries including streams of stars from disrupted dwarf galaxies, the Galactic merger history, and populations of black holes detectable through their gravitational influence on binary star companions. Gaia has also discovered thousands of exoplanets, binary stars, asteroids, and quasars as secondary products of its all-sky survey.