A team of astronomers at the University of Cambridge is taking the next big step in a European-wide programme that will lead to the creation of the first three-dimensional map of more than a billion stars.
A powerful data centre, which was turned on yesterday at the Institute for Astronomy (IoA), will process the vast amount of imaging data sent back to Earth by a satellite that is due to be launched into space in August 2013. The Gaia satellite, whose heart is the largest digital camera ever built, will orbit the Sun at a distance of 1.5km from Earth and will feed the data centre with a billion-pixel video of a billion stars, galaxies, quasars and solar system asteroids for five years after launch.
The Gaia satellite, which has been hailed as the premier European astrophysics space mission of the decade, will deliver an extraordinarily precise census of the Milky Way in three dimensions.
‘As Gaia slowly spins, it will create a billion-pixel video of the Milky Way, watching everything move, and deducing what is there, and where it is,’ explained Professor Gerry Gilmore, from the IoA and the UK principal investigator for UK involvement in the mission. ‘On its five-year mission, Gaia will produce a vast amount of information – almost inconceivable in its scope.’
Gaia is one of the most important current space projects for the UK, which has won about €80 million of contracts from ESA to build parts of the spacecraft.
Remarkably, its two optical telescopes are capable of measuring the positions of celestial objects to an accuracy of up to 10 microarcseconds, comparable to the diameter of a human hair at a distance of 1,000km. To determine the properties of stars, Gaia will also split their emitted light into a spectrum before communicating the data back to Earth. After launch, a 10m diameter ‘skirt’ will unfold around the satellite to shade the telescopes and generate its own energy from solar panels.
Gaia is expected to discover a multitude of new objects both in our solar system – including brown dwarfs and white dwarfs, supernovae and extra-solar planets – as well probe the distribution of dark matter, map over 500,000 quasars in the Universe, and measure the local structure of space-time.
