**CAF Note: GAIA is the Grand Award Winner in the Aerospace category for Popular Science’s Best of What’s New 2013**
Gaia is an unmanned space observatory of the European Space Agency (ESA) designed for astrometry. The mission aims to compile a 3D space catalogue of approximately 1 billion astronomical objects (approximately 1% of the Milky Way population) brighter than 20 G magnitudes, where G is the Gaia magnitude passband between about 400 and 1000 nanometres light wavelengths. Successor to the Hipparcos mission, it is part of ESA’s Horizon 2000 Plus long-term scientific program. Gaia will monitor each of its target stars about 70 times over a period of five years.