The nucleus of a comet is primarily composed of ice, along with some rock and dust.

The coma is the bright, glowing region surrounding a comet's nucleus, which is caused by the sublimation of ice and the release of gas.

The solar wind, a stream of charged particles emitted by the Sun, interacts with the comet's coma and ionizes the gas, creating the comet's tail.

Comets have two main types of tails: ion tails and dust tails. Plasma tails are a type of ion tail, while gas tails are not a recognized type of comet tail.

Halley's Comet is a famous comet that is visible from Earth every 76 years and is known for its long, bright tail.

Halley's Comet has an orbital period of approximately 76 years, meaning it takes about 76 years to complete one orbit around the Sun.

Philae was a lander that was part of the Rosetta mission, which successfully landed on the nucleus of Comet 67P/Churyumov-Gerasimenko in 2014.

Shoemaker-Levy 9 Comet was famously known for its collision with Jupiter in 1994, which resulted in a spectacular series of impacts.

Hyakutake Comet was discovered in 1995 and became known for its extremely long tail, which stretched for millions of kilometers.

Hale-Bopp Comet was discovered in 1997 and became known for its bright greenish coma, which was visible to the naked eye for 18 months.

McNaught Comet was discovered in 2007 and became known for its extremely dusty tail, which was visible to the naked eye for several weeks.

ISON Comet was discovered in 2013 and became known for its extremely bright outburst, which made it visible to the naked eye for several weeks.

Lovejoy Comet was discovered in 2014 and became known for its extremely close approach to the Sun, passing within 1.5 million kilometers of the Sun's surface.

NEOWISE Comet was discovered in 2020 and became known for its extremely long tail, which stretched for millions of kilometers.

Leonard Comet was discovered in 2021 and became known for its extremely bright outburst, which made it visible to the naked eye for several weeks.