Non-periodic

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...

s are seen only once. They are usually on near-

parabolic orbit In astrodynamics or celestial mechanics a parabolic trajectory is a Kepler orbit with the eccentricity equal to 1 and is an unbound orbit that is exactly on the border between elliptical and hyperbolic. When moving away from the source it is ca ...

s that will not return to the vicinity of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

for thousands of years, if ever. Periodic comets usually have elongated

elliptical orbit In astrodynamics or celestial mechanics, an elliptic orbit or elliptical orbit is a Kepler orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0. In a stricter sense, i ...

s, and usually return to the vicinity of the Sun after a number of decades. The official names of non-periodic comets begin with a "C"; the names of periodic comets begin with "P" or a number followed by "P". Comets that have been lost or disappeared have names with a "D". Comets whose orbit has not been determined are designated with a "X" prefix.

Lists

List of comets by type This is a list of comets (bodies that travel in Elliptic orbit, elliptical, Parabolic trajectory, parabolic, and sometimes Hyperbolic trajectory, hyperbolic orbits and display a Comet tail, tail behind them) listed by type. Comets are sorted into ...

* List of comets visited by spacecraft *

List of comets with no meaningful orbit This is a list of comets designated with X/ prefix. The majority of these comets were discovered before the invention of the telescope in 1610, and as such there was nobody to plot the positions of the comets to a high enough precision to generate ...

* List of Great Comets *

List of Halley-type comets The following is a list of Halley-type comets (HTCs), which are periodic comets with an orbital period between 20 and 200 years, often appearing only once or twice within one's lifetime. The majority come from between the orbits of Saturn and Nept ...

List of hyperbolic comets This is a list of parabolic and hyperbolic comets in the Solar System. Many of these comets may come from the Oort cloud, or perhaps even have interstellar origin. The Oort Cloud is not gravitationally attracted enough to the Sun to form into a ...

* List of long-period comets * List of near-parabolic comets *

List of numbered comets This is a list of periodic comets that were numbered by the Minor Planet Center after having been observed on at least two occasions. Their orbital periods vary from 3.2 to 366 years. there are 436 numbered comets (1P–436P), most of them being ...

* List of periodic comets

External links

Bright Comet Chronicles

Comets currently above mag. 12
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Heavens-Above Heavens-Above is a non-profit website developed and maintained by Chris Peat as ''Heavens-Above GmbH''. The web site is dedicated to helping people observe and track satellites orbiting the Earth without the need for optical equipment such as b ...

{{DEFAULTSORT:comets Lists of small Solar System bodies

Lists

See also

External links