The Cosmological Evolution Survey (COSMOS) is an astronomical survey designed to probe the formation and evolution of galaxies
as a function of cosmic time (redshift) and large scale structure environment.
The survey covers a 2 square degree equatorial field with imaging by most of the major space based telescopes (Hubble, Spitzer, GALEX, XMM, Chandra) and a number of large ground based telescopes (Subaru, VLA, ESO-VLT, UKRIT, NOAO, CFHT and others).
Over 2 million galaxies are detected, spanning 75% of the age of the universe.
The COSMOS survey involves almost 100 scientists in a dozen countries.