Comet Halley is one of the most famous comets, known for its bright appearance and predictable orbit. It takes about 76 years to complete one orbit around the Sun. The last time it was visible from Earth was in 1986, and it will return again in 2061. This comet is named after the astronomer Edmond Halley, who calculated its orbit in 1705. Halley discovered that this comet was the same one observed in 1531, 1607, and 1682. His work confirmed that comets could have regular orbits, changing our understanding of these celestial objects.