The European Space Agency launches its GAIA satellite on a mission which it says "will have the key to unlocking the Milky Way galaxy".
DARMSTADT, GERMANY (DECEMBER 19, 2013) (REUTERS) - The European Space Agency's (ESA) huge star-surveying satellite GAIA successfully blasted into space from Kourou, French Guiana on Thursday (December 19) morning, on a mission the ESA said would "have the key to unlocking the Milky Way galaxy".
The chief scientist of the GAIA mission, Mark McCaughrean, said GAIA would have the key to unlocking the Milky Way galaxy. "It'll measure the positions of a billion stars but also their speeds, their motions," McCaughrean said. "With that we can run a movie of the Milky Way. We can run its forwards into the future, how the Milky Way will develop by looking at all the stars and how they move. But we can run it backwards as well, and we can see how the Milky Way actually formed in the first place."
The most sophisticated space telescope ever built by Europe, the 740-million-euro ($1.02-billion) gadget goes by the unofficial epithet of "discovery machine".
By repeating the observations as many as 70 times throughout its mission, the telescope can help astronomers calculate the distance, speed, direction and motion of these stars.
GAIA, using a six-sided "optical bench" three metres (10 feet) across to snare glimmers of light, is 200 times more sensitive than Hipparcos in measuring the angles that, through triangulation, determine a star's position.
GAIA's secondary objectives are equally stunning. By monitoring the "wobble" in stellar light as a planet passes in front of a star, it can add to knowledge about worlds beyond the Solar System.
By some estimates, it could detect as many as 50,000 planets within a distance of 150 light years from the Sun, or 10 times more than have been observed since the first was spotted in 1995.
GAIA will also be turning its eyes to our own Solar System, scouring its chill, dark fringes and the asteroid belt between Mars and Jupiter to help the search for any rocks that may one day threaten Earth.
Other potential bounty includes real-time observations of exploding stars, called supernovae, in distant galaxies and insights into strange "failed" stars, known as brown dwarves, that drift listlessly through interstellar space after failing to gain enough mass to ignite.
GAIA may provide a useful test of Einstein's theory of general relativity, which says that a star's position will appear to move slightly as a result of light from it that is deflected by a passing, massive object.
GAIA will take up position at the so-called Lagrange point L2, located 1.5 million kilometres (937,000 miles) from the Earth.
It is the go-to place for space observatories. L2 has been used by Europe's Herschel and Planck telescopes and is designated as the slot for NASA's eagerly-awaited James Webb Space Telescope (JWST).