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Physical Properties
21 km
4.8e16 kg
Orbit
Pluto
38.20177 d
Sources & Further Reading
- NASA — official mission / factsheet page
- Wikipedia — extensive cross-referenced article
- NASA u2014 Hydra
Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-04-18 18:19:26.
Hydra is the outermost small moon of Pluto, discovered by Hubble in 2005. It has a nearly pure water-ice surface (based on New Horizons 2015 spectra) and, like Nix, rotates chaotically.