Gaia 1783 days in orbit - Mission overview and early science results

The European Space Agency’s astrometry satellite Gaia was launched in December 2013. The main mission goal is to provide an accurate inventory of the motions, distances and physical properties of stars in the Milky Way Galaxy. Ultimately this will help us to understand the complex dynamical processes in a large spiral galaxy and unravel its formation history. The unique capability of Gaia is the accurate pinpointing of the locations, and hence the motions and parallaxes, for hundreds of millions of stars in a global reference frame. This is possible thanks to its extremely stable optical telescopes and large CCD camera operating under the favourable conditions in space. In April 2018 the second release of data was published – Gaia DR2, based on the first two years of observations from a projected lifetime of 10 years. To date more than 300 papers and preprints making used of the data have appeared, spanning a very wide range of topics from solar system objects and exoplanets to quasars. In this talk I will give a brief overview of how the satellite works and of some of the data analysis challenges. I will show examples of the early science results that already hint to the transformational impact the mission will have in many branches of astrophysics.