- Additional Information
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Additional Information
Short Description Hydra is the outermost known moon of Pluto. Hydra is in a 2:3 orbital resonance with Nix, and a 6:11 resonance with Styx . As a result of this "Laplace-like" 3-body resonance, it has conjunctions with Styx and Nix in a 5:3 ratio. Like Saturn's moon Hyperion, Nix, and the other small Plutonian moons, Hydra rotates chaotically; its day length and rotational axis vary quickly over astronomical timescales, to the point that it regularly flips over. Hydra (moon) - Wikipedia, the free encyclopedia Discovered by Hubble Space Telescope, Pluto Companion Search Team Discovery date 15 June 2005 Type Moon AddInfo Pluto III Satellite of Pluto Minor planet number 134340 Pluto III Orbit Prograde Rotation Direct Apoapsis 05 65 117 km Periapsis 05 64 443 km Semi-major axis 05 64 738 km Distance from Sun 02 39.54 au /5 Eccentricity 0.005 862 Orbital period 38.201 77 days Orbital speed 0.1233 km/s Inclination to the equator 000.242 Diameter/Size 02 47 km Dimensions 65 km × 45 km × 25 km Mass 1016×4.8 ± 4.2 kg Surface gravity 0 m/s2 Escape velocity 0 m/s Rotation period 0.4295 ± 0.0008 days (chaotic) Axial tilt variable Albedo geometric 0.83 ± 0.08 Temperature mean 02 44 K | −229 °C Apparent magnitude 22.9–23.3 - Comments
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