Neptune’s 16 moons

Where Hippocamp fits in a lopsided system.

Published 2026-10-23

Neptune has 16 known moons.^[7]

Triton dominates

Triton accounts for more than 99.5% of the mass orbiting Neptune.^[7]

A captured giant

Triton was captured from the Kuiper belt after Neptune’s original moons formed, destroying many of them.^[1]

The name

Showalter chose “Hippocamp” partly for his love of scuba diving and sea-horses; the IAU approved it on 20 February 2019.^[1]

Numbered citations link to the sources list on the Hippocamp overview page.