Gaia@home

Gaia@home is a volunteer computing project dedicated to processing data from the European Space Agency's Gaia space observatory, one of the most ambitious astronomical missions ever undertaken. Launched in December 2013 and operational until March 2025, Gaia measured the positions, parallaxes, proper motions, and brightnesses of over two billion stars — plus asteroids, quasars, and extragalactic objects — with unprecedented precision.

Converting Gaia's raw telemetry into a scientifically usable catalog is one of the largest data-reduction tasks in the history of astronomy. The mission produced petabytes of measurements, and extracting the final stellar positions requires iterative global solutions where every star's position depends on every other's. Gaia@home distributes selected scientifically-valuable sub-problems — such as simulating the instrument, generating mock catalogs to validate the pipeline, and running specialised astrophysical analyses — across volunteer computers.

The project is operated by Adam Mickiewicz University in Poznań, Poland, under an ESA contract within the Permanently Open Call for Proposals of the Polish Industry Incentive Scheme. Volunteers essentially act as a computing extension of the European astronomical community, freeing core mission resources for time-sensitive work.

Although the Gaia satellite was switched off on 27 March 2025, the data-reduction and catalog work will continue well into the 2030s — Gaia Data Release 4 and beyond are still being prepared. That makes Gaia@home meaningful right now: every work unit directly feeds catalogs that will shape galactic astronomy for decades.