Gaia is a space observatory of the European Space Agency (ESA) designed for astrometry:
measuring the positions and distances of stars with unprecedented precision.
The mission aims to construct the largest and most precise 3D space catalog ever made,
totalling approximately 1 billion astronomical objects, mainly stars but also planets, comets, asteroids and quasars among others.
Gaia was launched on 19 December 2013 by Arianespace using a Soyuz rocket flying from Kourou in French Guiana.
The spacecraft currently operates in a Lissajous orbit around the Sun–Earth L2 Lagrangian point.