Marco Werman: An ambitious European space agency mission to map space in 3D is now underway.
Werman: The Gaia space observatory blasted off into space earlier today atop a Russian Soyuz rocket from a launch pad in French Guiana. And as it did Mark McCaughrean watched nervously from the ESA center in Germany.
Mark McCaughrean: I mean, any time you stick 740 million euros worth of hardware on top of a controlled bomb, you get nervous.
Werman: But not to worry, the launch went well. McCaughrean is the ESA science adviser for the Gaia Mission. The basic aim, he says, is to create a giant 3D star catalog of the Milky Way which should allow scientists do do several things.
McCaughrean: The first one is understand the formation and evolution of the Milky Way we live in because once we measure the positions and the motions of all of the stars, a billion stars in our galaxy, we'll be able to trace those motions backwards and we'll be able to see how the galaxy was actually put together billions of years ago. But that very same catalog can then be used to see stars wobbling around slightly on the sky and that will be because they have planets going around them, exoplanets, planets going around stars other than the sun. We'll discover thousands of those.
Werman: Gaia's telescopes will also look for supernovas, those are exploding stars, and asteroids in the hope of spotting any rogue space rocks that may be headed our way. But the mission's first task would be to find a parking place in space. Gaia will take about three months to get to its assigned spot behind the earth as seen from the sun. Then what McCaughrean calls the astronomical census will begin, repeatedly measuring the positions, motions, temperature, and luminosity of a billion stars. And he says that could lead to some new discoveries.
McCaughrean: We need to know where they are. We need to be able to place them in context within the Milky Way and Gaia will provide us this enormous fantastic, if you like, a grid, a map of the Milky Way in which all of the star-forming regions will be locked down. We'll be able to really understand how star formation progresses in the Milky Way today because many stars have been around for millions of years, but stars are being born every day in the Milky Way and by placing them with Gaia's results we'll understand much better how star formation propagates throughout the Milky Way like wildfire. One fire or one star-forming region can set off another another. To be able to really define that we'll have to know the distances and Gaia will tell us that extremely accurately.
Werman: Some scientists hope the mission will help answer even bigger questions like "How did the universe begin?" Who knows what they'll find, right? McCaughrean says Gaia's 3D map of the Milky Way will generate more than thirty-thousand CD-ROMs worth of data. That's enough to keep scientists very, very busy for years.