Discovered in 1846, Triton is the largest moon of Neptune - but it’s unlike any other. Scientists believe it was once a free-floating planet before Neptune’s gravity captured it. Its ...

Triton, which is about 1,680 miles (2,700 kilometers) wide, has a unique property among large solar system moons: a retrograde orbit. [ Video: Fly By Neptune's Freezing Moon Triton ] ...

Neptune’s large moon Triton may have abandoned an earlier partner to arrive in its unusual orbit around Neptune. Triton is unique among all the large moons in the solar system because it orbits ...