Space telescopes·ESA

Gaia

ActiveLaunched in 2013·L2 — 1.5M km

Maps the position of 1.8 billion stars in our galaxy with unprecedented precision.

Main objectives

Did you know?

Measures star positions with the equivalent of telling apart a coin from 20,000 km away.

Timeline

Dec 19, 2013

Launch

Soyouz from Kourou, French Guiana.

Jul 25, 2014

Start of observations

At the L2 point.

Sep 14, 2016

Data Release 1

Catalog of 1.1 billion stars.

Jun 13, 2022

Data Release 3

Detailed data on 1.8 billion stars.

[03]

ASTRO

Main astrometric instrument (positions).

BP/RP

Blue/red photometer.

RVS

Radial velocity spectrometer.

Mass2,030 kg

OrbitLissajous around L2

Precision24 microarcseconds

Telescopes2 × 1.45 × 0.5 m

[05]

DiscoveryBreakthrough
Closest dormant black hole
Gaia BH3 (~2 kpc): a 33 M☉ stellar black hole detected through pure astrometry.
Aug 06, 2024
MilestoneMajor
Data Release 4 — astrometry focus groups
Second batch of DR4: positions and proper motions for ~500 million sources, refinement of binaries and astrometric exoplanets.
Oct 15, 2025 ↗
DiscoveryBreakthrough
Data Release 3 — binary stars & spectra
1.8 billion stars plus more than 800,000 binary systems. Detection of Gaia BH1, the closest black hole to the Sun.
Jun 13, 2022
MilestoneMajor
Focus Group 5 — partial catalogue
First batch of Data Release 4: positions and motions for ~500 million sources.
Apr 03, 2025 ↗
DiscoveryMajor
Data Release 3
Detailed data on 1.8 billion stars.
Jun 13, 2022