Satellite GAIA - Illustration - Vue du satellite europeen GAIA sur fond de voie lactee....

Satellite GAIA - Illustration - Vue du satellite europeen GAIA sur fond de voie lactee. L'objectif de la mission Gaia est de realiser le plus grand recensement possible des astres de notre Galaxie et d'en creer une carte en 3D d'une tres grande precision. Le satellite determinera la position, la couleur et le mouvement propre d'un milliard d'etoiles. Gaia a ete lance depuis Kourou le 19 decembre 2013. Artist's impression of Gaia. Gaia is an ambitious mission to chart a three - dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population. Combined with astrophysical information for each star, provided by on - board multi - colour photometry, these data will have the precision necessary to quantify the early formation, and subsequent dynamical, chemical and star formation evolution of the Milky Way Galaxy. Additional scientific products include detection and orbital classification of tens of thousands of extra - solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our Solar System, through galaxies in the nearby Universe, to some 500 000 distant quasars. It will also provide a number of stringent new tests of general relativity and cosmology. Gaia was launched from Europe's Spaceport in French Guiana on december 19 2013