In the first 14 months of its five-year surveying mission, Gaia also mapped the distances and motions across the sky of more than two million stars, the European Space Agency (ESA) said as it presented the first set of data from Gaia on Wednesday.
ESA launched Gaia in December 2013 to log the position, colour and brightness of around a billion stars, sending it to an orbit around the sun around 1.5 million km (932,000 miles) from Earth.
Equipped with two telescopes housing mirrors of various shapes and sizes, the 2-tonne satellite can see a hundred times farther and measure stars' position and motion 200 times more accurately than Hipparcos, the first space mission to measure stellar positions, which ESA operated from 1989 to 1993.
"Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before," Alvaro Gimenez, ESA's director of science, said in a statement.
Scientists hope that studying the stars will allow them to peer back in time, to when the galaxy was first forming.
Scientists also expect Gaia to discover new planets and asteroids as well as distant supernovas and quasars, the hot and bright cores of galaxies.
Gaia, designed and built by Astrium - now part of Airbus Defence and Space, is expected to collect enough data over five years to fill more than 1.5 million CD ROMs. The data will be freely available to the astronomical community.
US space agency NASA has been working on similar programmes. It is planning a two-year surveying mission called Transiting Exoplanet Survey Satellite (TESS), which is to use wide-field cameras to detect planets ranging from Earth-sized to gas giants.
Another mission, called SIM, which was to search for potentially habitable planets, was shelved.