MW-GAIA will provide European leadership in understanding the Galaxy, its stars and planets, enhance the potential of the community in its scientific exploitation of the observations of more than a billion stars with the European Space Agency’s Gaia satellite, and enhance the development of the next steps in astrometry and space astrometry missions.

The Action brings together key stakeholders from across Europe, to leverage expertise, and develop new techniques to fully maximize the scientific returns from Gaia‘s rich and complex data.

Five key challenges are addressed: (i) The Milky Way as a Galaxy; (ii) The Life and Death of Stars; (iii) Planetary Systems Near and Far; (iv) Gaia Fundamentals: Space and Time; and (v) Astrometry Innovation Challenge — towards sub-μas astrometry. COST enables the vital Action activities, supporting exchanges, training and meetings.

Key objectives are to increase science impact and European leadership in the scientific exploitation of Gaia, developing new techniques in the analysis and interpretation of the Gaia data. The Action technological impact is through the delivery of a key science-technical roadmap to identify the requirements and challenges in developing a future space astrometry mission building on Gaia, but moving to the sub-μas realm (thus opening up discovery space to the Local Group of galaxies).

The Action will have a significant legacy, creating a dynamic and vibrant network of researchers with expertise in the study of the Milky Way, its constituents and the art of astrometry. Participation is inclusive, with researchers accessing the network from across Europe, irrespective of their gender or location.