On February 9, 1986, Halley's Comet swung closest to the Sun on its most recent visit to the inner solar system. Halley is the most famous comet in history - a chunk of dirty ice about 15 kilometres across that swings around the Sun once every 75 to 76 years. People have been writing about it for at least 2,200 years. Chinese astronomers recorded it in 240 BCE, and it appears in the famous Bayeux Tapestry showing the Norman invasion of England in 1066.
The 1986 visit was the first time humans could send spacecraft to meet a comet up close. A small armada from Europe, the Soviet Union, and Japan flew through the comet's tail. Europe's Giotto spacecraft got within 600 kilometres of Halley's icy core, snapping the first photos of a comet's nucleus - a dark, peanut-shaped boulder hissing dust and gas into space.
Halley won't be back until July 2061. If you're under 12 right now, you have a good chance of seeing it. Until then, it's drifting silently out past the orbit of Neptune, slowly turning around for its next pass.
