Comets

A comet is an icy, small Solar System body or interstellar object that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or coma surrounding the nucleus, and sometimes a tail of gas and dust gas blown out from the coma. These phenomena are due to the effects of solar radiation and the outstreaming solar wind plasma acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small roc

theoretical cloud of planetesimals at the far edge of the solar system

cloud of gas or a trail around a comet or asteroid

the solid, central part of a comet

Exceptionally bright comets

dust or gases blown off a comet by solar wind in the inner solar system, leaving a visible trail

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location in the extreme Solar System

bodies orbiting within the main asteroid belt which have shown cometary activity during part of their orbit

designation of an astronomical body after its discovery and before its official name

comet that lacks typical activity

comet not sighted when expected based on a previously-established periodicity

type of cosmic dust

first sighting of unidentified flying objects

history and current system of naming comets

small stone, thought to be the first known specimen of a comet nucleus

Overview of Chinese records of comets

Rocky, minor, celestial body

hypothetical object