The Point.fr – Published on 12/18/2013 at 13:00 – Modified on 12/19/2013 12:07
It is a European space mission, if all goes well, could be a great leap for astronomy. The Gaia satellite of the European Space Agency (ESA), built by Astrium in Toulouse, took off Thursday morning at 10 h 12 (Paris time) from the space center Sinnamary, French Guiana, with a Soyuz rocket . Arianespace announced that the takeoff was uneventful, as the separation of Gaia launcher 41 minutes later. Gaia must then go to position 1.5 million km from Earth at the point called Lagrange L2. Once in orbit around this point, the mission Gaia, colossal if any, will be a three-dimensional atlas of the whole of our galaxy, the Milky Way, and even a portion of its neighborhood .
Distance, movement, brightness, color, gear measuring roughly 4 x 4 meters, for a weight of two tons, will screen more than a billion stars ( with the exception of 6000 brightest stars of magnitude less than 6), including very faint stars down to magnitude 20 (plus magnitude, the lower the star is bright. Thus magnitude of the Sun is it to – 27). In comparison, its predecessor Hipparcos, launched in August 1989, was able to determine the position of only 2.5 million stars, and with a precision hundred times lower. Gaia will scan each of the stars about 70 times, at different times, to check measurements, but more importantly, to identify possible changes in the behavior of celestial bodies. This amounts to a complete observation of the sky every six months. But the stars are not everything. Scientists also hope to collect as much data on more than a million galaxies, 500,000 quasars, 20000 à 30000 supernovae, at least tens of thousands of asteroids, comets, and also provide plentiful harvest of exoplanets.
In practice, throughout the duration of the mission scheduled to last five years and whose total cost is estimated at nearly a billion euros, the satellite will provide information for eight hours each day, six centers mobilizing data processing in Europe. A key is also established in France, CNES Toulouse. At a minimum, all of the work of Gaia should be a petabyte of data or memory required to store about 20,000 Blu-ray. Enough to feed the scientific research for several decades. With this information, astronomers and astrophysicists hope to understand the internal organization of our galaxy, a better understanding its genesis and evolution, discover new exotic celestial bodies, but who knows, finally find the trace of the famous dark matter would the missing mass of the Universe.
Look at the pictures of the launch:
Watch this video presentation of the Gaia mission