Hale-Bopp, Comet

Comet discovered in 1995 by the amateur astronomers Alan Hale and Thomas Bopp at a distance from the Sun of about seven astronomical units, beyond Jupiter's orbit and farther than any comet detected before by amateurs. Astronomers estimated its nucleus to be at least 20 mi (30 km) in diameter. At its closest approach to the Sun in April 1997, it was one of the intrinsically brightest comets in several centuries, though not the brightest as seen from Earth. The approach of the comet triggered the mass suicide near San Diego, Calif., U.S., in March 1997 of 39 members of a religious cult known as Heaven's Gate, whose leader maintained that they would be reincarnated in a spacecraft following in the comet's wake.

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