Palomar Planet-Crossing Asteroid Survey
The Palomar Planet-Crossing Asteroid Survey (PCAS) was initiated by Eleanor F. Helin and Eugene M. Shoemaker in 1973.[1][2][3][4] This program is responsible for the discovery of 95 Near-Earth Asteroids (NEAs) and 17 comets.[5] PCAS ran for nearly 25 years until June 1995.[5] It is the immediate predecessor of the Near Earth Asteroid Tracking (NEAT) program.[5]
Notable discoveries
The first NEA discovered by PACS was (5496) 1973 NA, an Apollo-type asteroid with an orbital inclination of 68 degrees, still the highest known among NEAs. In 1976 they discovered 2062 Aten, 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, they have a particularly high probability of colliding with the Earth. In 1979, they found an asteroid, (4015) 1979 VA, that they later identified with the comet 4015 Wilson–Harrington. It was the first confirmation that a comet can evolve into an asteroid after it has degassed.[5]
Publications
- 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.
See also
References
- ↑ 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.
- ↑ 5.0 5.1 5.2 5.3 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 822 (1 Near-Earth Ob): 6–25. Bibcode:1997NYASA.822....6H. doi:10.1111/j.1749-6632.1997.tb48329.x.