Astrophysics (index)about

irregular moon

(irregular satellite)
(moon with an atypical orbit, such as retrograde)

The term irregular moon (or irregular satellite, referring specifically to natural satellites) is generally used to refer to a moon with an atypical orbit, such as Triton with its retrograde orbit, but also referring to other atypical characteristics such as a substantial inclination, e.g., from the ecliptic. For a particular study, a clear definition is undoubtedly stated and observed. Most of the many moons of the outer planets are considered irregular.

It is thought that they are generally captured minor planets.

A regular moon (or regular satellite) is essentially one that is not irregular.


(moons,solar system)
http://en.wikipedia.org/wiki/Irregular_moon
http://en.wikipedia.org/wiki/Regular_moon

index