As the successor to the highly successful Hipparcos space astrometry project, Gaia was approved last year as an ESA "cornerstone mission" and is set for a launch around 2012. One of the project's goals is to engage the interest and participation of the next generation of astronomers.

The Hipparcos satellite (1989-93) revolutionized astrometry -- the science of star measurement -- by fixing the position, brightness, color and variation of millions of stars in our vicinity far more accurately than ever before.

Previously, astrometry was a difficult, backwater subject of interest to only a few specialists, but the data Hipparcos returned are still impacting on every branch of astronomy -- from cometology to cosmology.

The European Space Agency is convinced that Gaia will be 100 times better than Hipparcos. By charting a billion stars, including many much farther away than Hipparcos could see, Gaia will create an unprecedented picture of the positions and motions of stars across most of the Milky Way Galaxy.

In addition to transforming the science of stars and galaxies, Gaia is likely to be a top discoverer of asteroids and extrasolar planets. But a new generation of human eyes are needed to interpret the results.

"Gaia will deliver its first results more than 10 years from now," noted Michael Perryman, Gaia's project scientist. "Key individuals have already devoted half their working lives to conceiving and accomplishing Hipparcos, and to inventing Gaia. Who'll pick up the baton when they retire? That's the question."