Gaïa transmits 500 million data to earth every day, which makes it possible to establish a 3D cartography of the Galaxy, the Milky Way. The veil is thus lifted on the formation, composition and evolution of the universe.
Gaïa is a probe that navigates a million and a half miles from the earth. She walks in our universe which is close (Solar system) but also in more distant galaxies). She constantly observes the sky. The 500 million data collected every day converge on the earth and they are processed by computers, then exploited by astronomers.
Launched from Kourou by a Soyuz-Fregat rocket on December 19, 2013 at 10:12 a.m. Paris time, Gaïa is therefore the name of the probe, but also that of a major project of the European Space Agency (ESA). And since 2013, a team from the Côte d’Azur Observatory has been dedicated to this project.
We try to understand how the planets were formed, how the earth was formed. It is known that the asteroids have made their contribution so that there is water on earth somewhere. They are related to the birth of life.
Paolo Tanga, astronomer at the Observatory of the Côte d’Azur
This Monday, June 13, ESA therefore presented a new catalog, a cartography eagerly awaited by astronomers around the world. Because for 18 years, Gaïa has been improving knowledge of our Galaxy, the Milky Way, in real time and in 3D, and has revealed its composition, formation and evolution.
Gaia allows us to measure the depth of the sky, how far apart the stars are. We have a moving 3D cartography, with information on the nature of matter, the chemical composition of the objects encountered.
Alejandra Recio Blanco, astronomer at the Côte d’Azur Observatory
Gaia thus provides with unprecedented accuracy the position of nearly 1.8 billion stars listed, or nearly 1% of all those in the Milky Way.
Alejandra Recio Blanco gives us some explanations. Assembled in Toulouse at Airbus, Gaïa is made of a special ceramic that is resistant to temperature variations. This “giant camera” captures starlight which is reflected on two mirrors oriented towards a very large sensor. Spectrum, moving speed data is recorded. And the inside of the probe includes a prism that dispenses a rainbow. When colors are missing, they have been absorbed by the atoms and molecules in the star’s atmosphere. The absence of colors is in a way the DNA of the star.
This program revolutionizes for astronomers but also for the general public, our knowledge of the universe. A window to the sky that spans hundreds of light years.
