Neptune's largest moon, Triton, was originally a member of a duo orbiting the Sun but was kidnapped during a close encounter with Neptune, a new model suggests. Triton is unique among large moons in that it orbits Neptune in a direction opposite to the planet's rotation, which long ago led scientists to speculate that the moon originally orbited the Sun. But until now, no convincing theory for how Triton paired with Neptune existed. Gravity might have pulled Triton away from its companion to make it an orbiting satellite of Neptune, researchers report in a new study published in the May...