Astrometry is the area that deals with the positions and motions of celestial objects.
It has two main scientific objectives to provide:
- A stellar reference frame to which the motions of celestial objects (Solar System and beyond) may be referred
- Basic observational data for the studies of stellar properties (luminosities, mass, etc.) by describing the spatial distribution of stars within the Galaxy, and their motions.
Measurements of distances to celestial objects, by triangulation for example, is at the core of astrometry and forms the basis of all astrophysics; without knowing the distances to planets, satellites, stars, and galaxies, no correct understanding of the cosmos in which we live can be achieved.