Neptune's moon and ring system stand out among the giant planets because of the strange imbalance between its one very large moon and its many tiny moons. Its largest moon, Triton, makes up more than 99% of the mass of all satellites orbiting the planet while orbiting retrograde compared with Neptun e's rotation. The predominant theory is that Triton is a captured Kuiper Belt object that caused a major disruption in Neptune's early moon system. Now, a new study published in Science Advances provides spectroscopic evidence to support this theory. ...read more read less