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Palomar Planet-Crossing Asteroid Survey

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Minor planets discovered: 20^[1]
see§ List of discovered minor planets

ThePalomar Planet-Crossing Asteroid Survey (PCAS) was anastronomical survey, initiated by American astronomersEleanor Helin andEugene Shoemaker at the U.SPalomar Observatory, California, in 1973.^[2]^[3]^[4]^[5] The program is responsible for the discovery of 95near-Earth Objects including 17comets,^[6] while theMinor Planet Center directly credits PCAS with the discovery of 20 numberedminor planets during 1993–1994.^[1] PCAS ran for nearly 25 years until June 1995. It had an international extension,INAS, and was the immediate predecessor of the outstandingly successfulNEAT program.^[6]

The first NEO discovered by PACS was(5496) 1973 NA, anApollo asteroid with an exceptionalorbital inclination of 68°, themost highly inclined minor planet known until 1999. In 1976, Eleanor Helin discovered2062 Aten,^[7] the first of a new class of asteroids called theAten asteroids with small orbits that are never far from Earth's orbit. As a result, these objects have a particularly high probability ofcolliding with the Earth. In 1979, Helin discovered an Apollo-type asteroid, that they later identified with the comet4015 Wilson–Harrington.^[8] It was the first confirmation that a comet can evolve into an asteroid after it has degassed.^[6]

^^a ^b"Minor Planet Discoverers (by number)".Minor Planet Center. November 16, 2016. RetrievedJanuary 24, 2017.
^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.
^Gehrels, Tom, ed. (1994).Hazards due to comets and asteroids. Tucson: Univ. of Arizona Press. pp. 129–131, 137.ISBN 9780816515059.
^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.
^Levy, David H. (2002).Shoemaker by Levy: the man who made an impact. Princeton, N.J.:Princeton University Press. pp. 167–174.ISBN 9780691113258.
^^a ^b ^cHelin, 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.822: 6.Bibcode:1997NYASA.822....6H.doi:10.1111/j.1749-6632.1997.tb48329.x. RetrievedJanuary 7, 2017.
^"2062 Aten (1976 AA)".Minor Planet Center. RetrievedJanuary 7, 2017.
^"4015 Wilson-Harrington (1979 VA)".Minor Planet Center. RetrievedJanuary 7, 2017.

Helin, E.F.; Shoemaker, E.M. (December 1979). "The Palomar planet-crossing asteroid survey, 1973–1978".Icarus.40 (3):321–328.Bibcode:1979Icar...40..321H.doi:10.1016/0019-1035(79)90021-6.
Helin, E. F. (1991). "Palomar Planet-Crossing Asteroid Survey (PCAS): Recent discovery rate".Asteroids, Comets, Meteors:235–236.Bibcode:1992acm..proc..235H.

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