Late 20th century
- 1981 — Robert Kirshner, August Oemler, Paul Schechter, and Stephen Shectman find evidence for a giant void in Boötes, 250 to 330 million light years across.[12]
- 1985 — Robert Antonucci and J. Miller discover that the Seyfert II galaxy NGC 1068 has broad lines which can only be seen in polarized reflected light.
- 1986 — Amos Yahil, David Walker, and Michael Rowan-Robinson find that the direction of the IRAS galaxy density dipole agrees with the direction of the cosmic microwave background temperature dipole.
- 1987 — David Burstein, Roger Davies, Alan Dressler, Sandra Faber, Donald Lynden-Bell, R. J. Terlevich, and Gary Wegner claim that a large group of galaxies within about 200 million light years of the Milky Way are moving together towards the "Great Attractor" in the direction of Hydra and Centaurus.
- 1987 — R. Brent Tully discovers the Pisces–Cetus Supercluster Complex, a structure one billion light years long and 150 million light years wide.
- 1989 — Margaret Geller and John Huchra discover the "Great Wall", a sheet of galaxies more than 500 million light years long and 200 million wide, but only 15 million light years thick.
- 1990 — Michael Rowan-Robinson and Tom Broadhurst discover that the IRAS galaxy IRAS F10214+4724 is the brightest known object in the Universe.
- 1991 — Donald Gudehus discovers a serious systematic bias in certain cluster galaxy data (surface brightness vs. radius parameter, and the
method) which affect galaxy distances and evolutionary history; he devises a new distance indicator, the reduced galaxian radius parameter,
, which is free of biases.
- 1992 — First detection of large-scale structure in the cosmic microwave background indicating the seeds of the first clusters of galaxies in the early Universe.
- 1995 — First detection of small-scale structure in the cosmic microwave background.
- 1995 — Hubble Deep Field survey of galaxies in field 144 arc seconds across.
- 1998 — The 2dF Galaxy Redshift Survey maps the large-scale structure in a section of the Universe close to the Milky Way.
- 1998 — The Hubble Deep Field South is compiled.
- 1998 — Discovery of accelerating universe.[13]
- 2000 — Data from several cosmic microwave background experiments give strong evidence that the Universe is "flat" (space is not curved, although space-time is), with important implications for the formation of large-scale structure