Respuesta :
It was either hit by something large which changed it's orbit pattern, or it was a foreign object from another place and originally had that orbit but at some point fell into Neptune's orbit
Answer:
Triton is the largest of Neptune's 13 moons. It is unusual because it is the only large moon in our solar system that orbits in the opposite direction of its planet's rotation―a retrograde orbit. Scientists think Triton is a Kuiper Belt Object captured by Neptune's gravity millions of years ago.