What are types of comets?

Comets with short periods, lasting less than 200 years, and those with long periods, originating from Oort's cloud, having an unknown duration.

A comet is an icy body which can be anything from a few tens of metres to tens of kilometres in size. The consist of ices and dust and rocky material.

Comets have highly elliptical orbits. At perihelion they come quite close to the Sun and the icy material vaporises to form the characteristic tail. A comet's tail can be more than 1 AU long - more than the distance between the Sun and the Earth.

One thing which distinguishes comets is their period. The defining time is 200 years. Their aphelion is in the outer solar system beyond Jupiter and often beyond Neptune, Their orbits are usual close to the plane of the ecliptic.

Long period comets tend to have very eccentric orbits. Their aphelia can be thousands of AU away. Some long period comets exhibit hyperbolic orbits. This means that they should leave the solar system, but they are often put back into elliptical orbits by the gravity of the outer planets.

Some comets have been detected in other solar systems.

Comets with long and short periods.