Palomar Planet-Crossing Asteroid Survey

near-Earth Objects including 17 comets,^[6] while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor 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 successful NEAT program.^[6]

most highly inclined minor planet known until 1999. In 1976, Eleanor 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.^[6]