Online Astronomy eText: Galaxies and the Universe
GOODS Fornax Deep Image
 Tens of thousands of galaxies appear in this small area in Fornax (only one minute of arc across) photographed by the Hubble Space Telescope as part of a survey of the distribution of galaxies in space. It would take approximately 5 billion such images to cover the entire sky, leading to estimates that at least 50 billion galaxies comparable to or larger and more massive than ours lie within the "observable" universe. (NASA, ESA, GOODS Team, M. Giavalisco (STScI), apod030625)