Gaia: 3D Map of the Milky Way
ESA's Gaia charted the positions, distances and motions of nearly two billion objects; its 2018 and 2022 data releases underpin studies of the Galaxy.
Open in the interactive tree →Launched on 19 December 2013, Gaia observed from July 2014 to January 2025 and collected over three trillion observations; it measured positions of brighter objects to 24 microarcseconds and distances to the nearest stars to 0.001%. Data release 2 (April 2018) gave positions, parallaxes and motions for about 1.3 billion stars, and release 3 (June 2022) added Solar System, variability and astrophysical data. Results include the remains of a merger with a dwarf galaxy about 10 billion years ago (Gaia-Enceladus) and Gaia BH1, described as the closest known black hole to Earth at roughly 1,600 light-years; ESA retired the spacecraft on 27 March 2025, and release 4 is expected no earlier than December 2026.
Prerequisites
- First satellite (Sputnik)1957
- CCD image sensor1969Gaia's focal plane is a mosaic of CCDs
- Hubble Space Telescope1990
Unlocks
- Rubin and Roman sky surveys2026Rubin's sky positions are calibrated against Gaia's star catalogue
- Dark MatteropenGaia's star motions weigh the Milky Way and map its dark-matter halo