Why does Triton have retrograde motion?

Answer 1

The orbit of Triton is what's known as a retrograde orbit. This means that the moon orbits in the complete opposite direction of the planet's rotation. Triton is the only large moon discovered in our solar system so far that does this.

Scientists and astronomers are not sure why this happens.

One theory is that the moon condensed this way from original material in the early solar system.

Another theory, and the most widely accepted theory, is that Triton was not originally a moon of Neptune, that it was formed elsewhere and was captured by Neptune's gravity. As a matter of fact, the surface features of Triton and the size of Triton are very similar to the dwarf planet Pluto. From time to time, Pluto does cross Neptune's path of orbit, so it is very likely that Triton was either a dwarf planet itself or a moon of Pluto before Neptune's gravity forced it to switch orbits.

Answer 2

First, the question should say "Uranus and Venus". By "opposite" we mean opposite to the direction off all the other planets.

In the case of Uranus it is probably a result of massive impacts that changed its spin axis direction.

For Venus it may also be something to do with collisions. Alternatively there

are theories suggesting it may have something to do with the action of the extremely dense Venus atmosphere.

Answer 3

Neptune's largest moon, Triton, revolves backwards.

The orbit of Triton is what's known as a retrograde orbit. This means that the moon orbits in the complete opposite direction of the planet's rotation. Triton is the only large moon discovered in our solar system so far that does this.

Scientists and astronomers are not sure why this happens.

One theory is that the moon condensed this way from original material in the early solar system.

Another theory, and the most widely accepted theory, is that Triton was not originally a moon of Neptune, that it was formed elsewhere and was captured by Neptune's gravity. As a matter of fact, the surface features of Triton and the size of Triton are very similar to the dwarf planet Pluto. From time to time, Pluto does cross Neptune's path of orbit, so it is very likely that Triton was either a dwarf planet itself or a moon of Pluto before Neptune's gravity forced it to switch orbits.

Answer 4

1) it doesn't really ... it's tilted about 90 degrees, so it spins on its side.

2) A planet's "spin" is the result of ALL the various collisions in the lifetime of the planet ... thus its random.

Answer 5

Any time that a moon orbits in the opposite direction of the planet's rotation and the orbits of its other moons, it is likely that the moon did not form when the planet did but instead was passing the planet when it got captured by its gravity.

Answer 6

Triton has a retrograde orbit because it was captured rather than formed. It is thought that it was a dwarf planet in the Kuiper belt before being captured by Neptune.

Answer 7

Triton was "captured" by Neptune and that resulted in the weird orbit.