Also found in: Acronyms.
Great ObservatoriesNASA's four major orbiting observatories launched between 1990 and 2003. In chronological order of launch, they are: the Hubble Space Telescope (HST), observing at ultraviolet and optical wavelengths; the Compton Gamma Ray Observatory (CGRO); the Chandra X-Ray Observatory, which originally was to form part of the more ambitious Advanced X-Ray Astrophysics Facility (see AXAF); and the Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility. Of the four satellites, only the Compton Gamma Ray Observatory had ended its mission by the start of 2005. In June 2004 NASA announced that the three Great Observatories still in orbit would collaborate with the European Space Agency's XMM-Newton satellite and some of the best groundbased observatories on a survey of deep sky objects called the Great Observatories Origins Deep Survey (GOODS). This survey will focus on two 150-square-arcminute portions of sky, one in the center of the Hubble Deep Field North, the other in the Chandra Deep Field South. GOODS will provide a multi-wavelength analysis of these regions to supply us with a rich legacy of data that will extend our knowledge about the remote and early universe.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006