The Oort clood /ˈɔːrt/[1] (named efter the Dutch astronomer Jan Oort), or Öpik–Oort clood,[2] is a hypothesized spherical clood o predominantly icy planetesimals that mey lie roughly 50,000 AU, or nearly a licht-year, frae the Sun.[3] This places the clood at nearly a quarter o the distance tae Proxima Centauri, the nearest starn tae the Sun.


  1. "Oort". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public leebrar membership required.)
  2. Whipple, F. L. (30 September 1987). "A Review of Cometary Sciences". Philosophical Transactions of the Royal Society A. Royal Society Publishing. 323 (1572): 339–347 [341]. Bibcode:1987RSPTA.323..339W. doi:10.1098/rsta.1987.0090. Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. Alessandro Morbidelli (2006). "Origin and dynamical evolution of comets and their reservoirs of water ammonia and methane.". arXiv:astro-ph/0512256 [astro-ph].