Aster › Space program › Hydra
Hydra
Position on the route: 80/130 · level needed 312 · journey (Mk0 engine) 59.1 h
By the numbers
| Diameter | ≈ 51 km |
|---|---|
| Year | 38.2 days |
| Distance | 64,800 km |
| Found | 2005, Hubble |
The story
Hydra is Pluto’s outermost moon; Hubble found it in 2005. It is named for the many-headed monster Heracles defeated. About 51 km, partly almost pure water ice; like Pluto’s other small moons it tumbles chaotically, and their orbits are close to resonance.
New Horizons’ 2015 images showed a very bright surface (albedo ≈ 83 %): as if reassembled from the debris of the Pluto–Charon collision.
Missions
- New Horizons (2015): flyby and imaging
Colony note
No colony; an outpost for ice.
What probes bring back
- Pluto’s outermost moon, ≈51 km; the surface is almost pure water ice; it tumbles chaotically in New Horizons’ 2015 images.