Gaia was aspace observatory. It was launched by the European Space Agency (ESA) on 19 December 2013.[1] The mission aims to compile a 3D space catalogue of about one billionastronomical objects.[2][3] The mission ended in March 27, 2025.
It will study about 1% of theMilky way population.[4][5] A successor to theHipparcos mission, it is part of ESA's Horizon 2000 Plus long-term scientific program. Gaia monitored each of its targetstars about 70 times over a period of five years.
Gaia created an extremely precise three-dimensional map of stars throughout theMilky Way galaxy and map their motions. This data is a product of the origin and subsequent evolution of the Milky Way. Thespectroscopic measurements will find the physical properties of each star observed, theirluminosity,temperature,gravity andelemental composition. Distances to about 20 million stars will be measured by annualparallax.
The massive stellarcensus will provide the basic observational data. With the data, astronomers hope to tackle a range of important problems, like the origin, structure, and evolutionary history of our galaxy. Large numbers ofquasars,galaxies,extrasolar planets andSolar System bodies will be measured at the same time.
Gaia was launched using aSoyuz rocket from its Guiana Space Centre (GSC) inFrench Guiana.[6][7] It is in aLissajous orbit around theSun–Earth L2Lagrangian point. As of April 2018 it has measured approximately a billion stars and other objects.
