Long-period comet
A long-period comet takes more than 200 years to orbit the Sun and comes from the distant Oort Cloud.
A long-period comet has an orbit lasting more than 200 years, often thousands or millions of years. Its orbit is usually very elongated and can be tilted at any angle, including backwards. Such comets are thought to come from the Oort Cloud, a vast shell of icy bodies surrounding the Solar System, from which they are occasionally nudged inwards by passing stars or the pull of the galaxy.
Many of the most spectacular comets in history were long-period ones, such as Hale–Bopp in 1997, which was visible to the naked eye for a record 18 months, and Comet NEOWISE in 2020. Because they may be visiting the inner Solar System for the first time, they can be rich in fresh ice.
Long-period comets also produce meteor showers. The Lyrids, peaking around 22 April, come from Comet Thatcher, which orbits every 415 years or so. Meteors from long-period comets are often very fast.
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