A space-based observatory launched in 1990 by NASA and ESA, providing high-resolution images of astronomical objects in visible, ultraviolet, and near-infrared light.
Source: nasa.gov
07/12/1997

In this 1994 Hubble Space Telescope photograph, every bright object is a galaxy. Oddly - most of them are spiral galaxies. This rich cluster of galaxies, named CL 0939+4713, is almost half way across the visible universe. Photos like this indicate that clusters in the past contained a higher fraction of spirals than do nearby clusters which are usually dominated by elliptical galaxies.