GALEX:
The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Such observations will tell scientists how galaxies, the basic structures of our Universe, evolve and change. Additionally, GALEX will probe the causes of star formation during a period when most of the stars and elements we see today had their origins.
Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29 month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing us closer to understanding how galaxies like our own Milky Way were formed.
GALEX will also identify celestial objects for further study by ongoing and future missions. GALEX data will populate a large, unprecedented archive available to the entire astronomical community and to the general public.
Scientists would like to understand when the stars that we see today and the chemical elements that make up our Milky Way galaxy were formed. With its ultraviolet observations, GALEX will fill in one of the key pieces of this puzzle.
