Palomar Planet-Crossing Asteroid Survey

The Palomar Planet-Crossing Asteroid Survey (PCAS) was an astronomical survey, initiated by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S Palomar Observatory, California, in 1973.[1][2][3][4] The program is responsible for the discovery of 95 near-Earth Objects (NEOs) including 17 comets,[5] while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor planets during 1993–1994.[6] PCAS ran for nearly 25 years until June 1995. It had an international extension, INAS, and was the immediate predecessor of the outstandingly successful NEAT program.[5]

Notable discoveries

The first NEO discovered by PACS was (5496) 1973 NA, an Apollo asteroid with an exceptional orbital inclination of 68°, the most highly inclined minor planet known until 1999. In 1976, Elenor Helin discovered 2062 Aten,[7] the first of a new class of asteroids called the Aten asteroids with small orbits that are never far from Earth's orbit. As a result, these objects have a particularly high probability of colliding with the Earth. In 1979, Helin discovered an Apollo-type asteroid, that they later identified with the comet 4015 Wilson–Harrington.[8] It was the first confirmation that a comet can evolve into an asteroid after it has degassed.[5]

See also

References

  1. ↑ Leverington, David (2003). Planetary vistas : a history of planetary astronomy up to the 21st century. New York: Cambridge University Press. pp. 339–340. ISBN 9780521808408.
  2. ↑ Gehrels, Tom, ed. (1994). Hazards due to comets and asteroids. Tucson: Univ. of Arizona Press. pp. 129–131, 137. ISBN 9780816515059.
  3. ↑ Barnes-Svarney, Patricia (2003). Asteroid : earth destroyer or new frontier? (Paperback ed.). Cambridge, Mass.: Basic Books, a member of the Perseus Books Group. p. 246. ISBN 9780738208855.
  4. ↑ Levy, David H. (2002). Shoemaker by Levy: the man who made an impact. Princeton, N.J.: Princeton University Press. pp. 167–174. ISBN 9780691113258.
  5. 1 2 3 Helin, Eleanor F.; Pravdo, Steven H.; Rabinowitz, David L.; Lawrence, Kenneth J. (May 1997). "Near-Earth Asteroid Tracking (NEAT) Program". Annals of the New York Academy of Sciences: 6. Bibcode:1997NYASA.822....6H. doi:10.1111/j.1749-6632.1997.tb48329.x. Retrieved March 2016. Check date values in: |access-date= (help)
  6. ↑ "Minor Planet Discoverers (by number)". Minor Planet Center. 24 February 2016. Retrieved March 2016. Check date values in: |access-date= (help)
  7. ↑ "2062 Aten (1976 AA)". Minor Planet Center. Retrieved March 2016. Check date values in: |access-date= (help)
  8. ↑ "4015 Wilson-Harrington (1979 VA)". Minor Planet Center. Retrieved March 2016. Check date values in: |access-date= (help)

Publications


This article is issued from Wikipedia - version of the 6/6/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.