Triton likely formed in the outer solar system before Neptune captured it, largely destroying the planet’s original moon system. JWST observations published in July 2026 suggest today’s inner moons reassembled from the wreckage — although Nereid may be one original survivor.

Triton likely formed in the outer solar system before Neptune captured it, largely destroying the planet’s original moon system. JWST observations published in July 2026 suggest today’s inner moons reassembled from the wreckage — although Nereid may be one original survivor.

Webb spectra suggest Neptune’s inner moons were rebuilt from destroyed icy interiors, while separate evidence casts eccentric Nereid as a possible original survivor.