James Webb Telescope Reveals Ancient Catastrophe Shaped Neptune's Inner Moons

Observations with NASA's James Webb Space Telescope of Neptune's inner moons Proteus, Larissa and Galatea, along with the planet's dusty rings, detected magnesium‑rich clay minerals. Such minerals form only through prolonged contact between liquid water and rock, indicating they originated from a larger, water‑rich body rather than the tiny, cold moons themselves. Lead author Ryleigh Davis of the University of California, San Diego explained that the material likely came from the deep interior of a now‑lost world.

The researchers propose that Triton, Neptune's largest moon, was captured from the Kuiper Belt early in the solar system’s history. Its gravitational influence would have destabilised Neptune’s original moons, causing collisions that produced debris. The present inner moons and rings are thought to have re‑formed from that wreckage, preserving evidence of the ancient disaster.