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2.8 Overall Scientific Objectives

Since its conception, the main scientific goal of the GAIA mission was a better understanding of the structure, formation and evolution of the Galaxy we live in. During the mission design phase, however, it was realized that its scientific potential was substantially more far-reaching. According to the extensive mission preliminary studies, all branches of astrophysics will greatly benefit from the immense quantity of extremely accurate data provided by GAIA.

Current understanding of the physics of individual stars will be revolutionized. Very accurate data covering the whole Hertzsprung-Russell diagram, from pre-main sequence to stellar death, will be available even for short-lived stellar evolutionary phases, not only for single stars but also for large numbers of binary and multiple systems. The spatial distribution of dark matter within the Galaxy will be determined. A census of the minor bodies in the Solar System, together with measurements of the number of planets around stars as a function of spectral type, will quantify planetary system formation modeling, and optimize the search for extra-trerrestrial life. A large, well-defined all-sky catalogue of galaxies and quasars will quantify studies of the structure of the local universe and of much larger scale structures at high redshift. The stars, galaxies, active galactic nuclei and quasars mapped by GAIA are the natural complement to surveys at other wavelengths, from ground-based radio observations to space-based high-energy measurements. Fundamental physics will benefit from local metric mapping, which will test general relativity to unprecedented accuracy. More specifically, the scientific topics that will be addressed by GAIA include ([Gilmore et al. 1998], [Straizys 1999] and [ESA 2000]):

Throughout the history of science, substantial enhancements of the measurement capabilities have always brought to the discovery of unpredicted phenomena. GAIA will provide multi-epoch astrometric, photometric and spectroscopic measurements of objects ranging from solar system objects to quasars, thus constructing the first all-sky phase-space map of the Galaxy as well as probing the large-scale structure of the low and high redshift universe. Further scientific results whose nature and importance cannot be foreseen are therefore to be expected. As Galileo wrote, ``if they could have seen what we now see, they would judge how we judge''.


next up previous contents
Next: 3. Scientific Case for Up: 2. The GAIA Mission Previous: 2.7 Expected Measurement Capabilities   Contents
Mattia Vaccari 2000-12-05