Astrophysics (Index)About


(Neptune I)
(Neptune's one significant moon)

Triton (Neptune I) is Neptune's largest moon, much larger than Neptune's other moons, and for a long time, Neptune's only known moon. Its radius is 1680 miles about 1/5 Earth radius, and its mass is on the order of 1/275 of Earth's. Cryovolcanism has been detected on it. Triton is in a retrograde orbit and because of this as well as its Pluto-like composition, it is thought to be a captured dwarf planet. Recent study of such captures suggest Triton might have previously been a minor planet with a binary companion: simulations show captures involving just two bodies require very particular circumstances, but three-body interactions involving a binary object with a third object can more easily result in such an exchange.

Further reading:
/Lookback Years

Referenced by pages:
irregular moon
Moon formation
retrograde orbit