Why do astronomers believe that Triton is a captured moon?
A)Triton is very small and potato- shaped, which is common of captured moons.
B)Triton is too large to have been formed in the "miniature solar nebula" thought to have surrounded Neptune in its very early history.
C)Triton appears to be made mostly of ice.
D)Triton orbits Neptune in a direction opposite that of Neptune's rotation.

Question

Quizplus · Accepted Answer

Triton's retrograde orbit is the strongest evidence that it is a captured moon. Since moons in a planet's orbit usually orbit in the same direction as the planet's rotation, the opposite direction of Triton's orbit suggests that it was not formed in the same way as Neptune's other moons.

Why Do Astronomers Believe That Triton Is a Captured Moon