Which celestial object is visible from Earth only about once every 76 years?

Halley's Comet is the most famous known comet, returning to the inner solar system approximately every 76 years. Named after English astronomer and mathematician Edmond Halley, the comet became famous after Halley predicted in 1705 that it would return in late 1758. When it reappeared in December 1758, his prediction proved correct and demonstrated that comets travel in predictable orbits. Its most recent appearance was in 1986, and it is expected to return again in 2061, making it a rare once-in-a-lifetime celestial sight.