Using JWST/NIRSpec, we identified aqueously altered phyllosilicates on Neptune’s small inner moons and rings. The observed Mg-endmember phyllosilicates (clay minerals) require prolonged interaction with liquid water to form, which means the original parent bodies of these moons were large enough to have undergone internal heating and hydrothermal processing. This points to a dramatic origin story: when Triton was captured as a Kuiper Belt Object, it may have dynamically disrupted Neptune’s original satellite system, and the current inner moons reaccreted from that debris — preserving a record of the differentiated interiors of the original system of much larger moon(s).
Our paper, “Triton’s Wake: Neptune’s Shattered Inner Moons Reveal Icy Body Interior Compositions”, is currently under review at Science Advances. A full research post will follow when the paper is out.
In the meantime, I gave an overview of this work as part of the Caltech Everhart Lecture series — you can watch it below: