Gaia, in a few days ready to map the Milky Way - Corriere della Sera

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Italy among the leaders of the mission

Gaia, in a few days ready
to map the Milky Way

will place in orbit around the Lagrangian point L2, to record one billion stars in our galaxy

Gaia, ESA’s European big eye that scrutinizes as never before our Milky Way galaxy, is in the midst of his journey towards the goal. Among ten days light his rockets to fit around an imaginary point, but real space is a half million miles from Earth. It is the point L2 baptized with the name of the L initial Lagrange Italian-French astronomer who calculated in the eighteenth century, along with four other points in the Earth-Moon-Sun. In practice, they are places of balance between the different forces of gravity around which a satellite can rotate around like a planet.

Gaia ready to map the galaxy

NOISELESS – Gaia was placed in L2 because, away from our globe, you can peer into the depths of galactic better without being disturbed: in earth orbit would periodically in the shade . Ten minutes after the start of the trip opened the big umbrella of solar cells that draw energy from, but at the same time protect the satellite from solar radiation preventing its heating and thereby improving the observations.

CENSUS – Gaia will make a census of one billion stars in the Milky Way, on the outskirts of which we inhabit. Certainly not all, since it calculates around 200 billion (but other estimates are even talking about the double), but it is a significant step forward compared to the work done twenty years ago by the Hipparcos satellite, always ESA, which launched in 1989 calculated the precise position of 118,200 stars and about a million more approximate. However, it is a real leap, enabled by technology focused in a digital camera (the largest ever launched into space) that will collect the light of the stars with a sensitivity never reached before. For example it will be like photographing a human hair from a distance of a thousand kilometers. And over the five-year mission will scrutinize each source at least seventy times.

COMMENTS – All this will serve to reconstruct a film, which could be reviewed at the time, history and evolution of our stellar island and to discover his (and our) possible future. In addition, Gaia will observe thousands of supernovae, stars now dead and exploded and calculating the exact displacement of normal stars will be able to detect the presence of planets around them. Will focus, then, his eye even in our solar system, finding new asteroids and specifying the orbits of the known ones that might threaten the Earth. Finally, make yet another examination of the theory of relativity of Einstein.

ITALY STAR – The task is difficult, but extraordinary by gathering a mountain of information (a million gigabytes equivalent to 200 thousand Dvd). “The Italian data collection site will be at the center of Turin Altec,” notes Enrico Saggese, President of ASI, a supporter of the European Commission, “and the numbers will derive a stereoscopic image of the highest quality result of the participation of our scientists and our industries. ” “Eight observers from the National Institute of Astrophysics,” says its president Giovanni Fabrizio Bignami, “will contribute to the mission and will be featured so that young researchers will have an opportunity to not go elsewhere.” The Italian involvement in the Gaia mission, therefore, is prominent, highlighting the international role held by our astronomers as well as by our technologists. “Seeing fly Gaia after years of work is seeing a dream materialized, as well as continuing a tradition of European research opened by the Hipparcos satellite,” says Giuseppe Sarri, Esa responsible for the ambitious project.

Giovanni Caprara