The James Webb Space Telescope has identified clay minerals on Neptune’s inner moons, offering chemical evidence of a major event in the planet’s early history. Researchers say the findings support the idea that Triton’s arrival disrupted and destroyed an older moon system roughly four billion years ago.
Neptune may once have been surrounded by several large moons moving in orderly, stable orbits. That arrangement could have resembled the organized moon systems seen around other giant planets before a Pluto-sized body entered the region.
Triton, Neptune’s largest moon, is widely considered to have arrived from elsewhere rather than forming alongside the planet. Its capture would have disturbed the existing moons, potentially triggering collisions and leaving debris that later formed some of Neptune’s smaller inner moons.
The clay minerals detected by JWST provide a chemical clue connecting those moons to material altered during the ancient upheaval. The observation adds support to a scenario in which Triton’s capture reshaped Neptune’s satellite system billions of years ago.
