Minor Planets & Near Earth Objects
During the course of its mission, Gaia will map all sources brighter than visual magnitude ~20. Among these will be thousands of Solar System objects, primarily main belt asteroids circling the Sun between the orbits of Mars and Jupiter. With its ability to detect faint and fast-moving objects, it is expected that Gaia will also detect several thousand Near-Earth Objects (NEOs), which are thought to be comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighbourhood.
Favourable observing conditions
Gaia will operate from the second Lagrange point L2 of the Sun-Earth system and will be able to observe down to an angular distance of 45° from the Sun. This allows for observations of objects in the asteroid blind spot between the Sun and Earth and to discover small bodies orbiting the Sun inside the Earth's orbit - a region that is virtually unobservable from the Earth. Objects that are in more exotic orbits are also potentially discovered by Gaia, during observations of the sky regions far from the ecliptic.
A refined classification of the population of minor bodies will emerge from the giant data base, revealing the kinship between asteroids, NEOs, and meteorites. In addition, the variation of physical parameters with the distance to the Sun will also be studied.