Halley's Comet is a famous periodic comet that is visible from Earth every 74 to 79 years. Known since the ancient times, its nature as a comet wasn't discovered until Sir Edmund Halley calculated its orbit in 1705. Its last perihelion occurred in 1986, and in that year it was visited by five spacecraft simultaneously. Its next return won't occur until 2061
Halley's Comet photographed by W. Litler on Easter Island, 1986-Mar-8
The nucleus of 1P/Halley as seen by the Giotto spacecraft, 1986-Mar-14
How to install add-ons? Find out here.