2-701-584 - Heritage Space/Heritage Images

Halley's Comet, 8 May 1910. The head of Halley's Comet as photographed by Dr George Willis Ritchey using the 60-inch (1.5-meter) telescope at Mount Wilson Observatory, California, USA. Halley's Comet is visible from Earth every 75-76 years. It is the only known short-period comet that is regularly visible to the naked eye, and the only naked-eye comet that might appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Its periodicity was first recognised by English astronomer Edmond Halley (1656-1742).