Styx
Moon· orbits Pluto
Styx is the smallest and faintest known moon of Pluto, an irregular sliver of ice discovered in 2012.
Open in 3D viewSee Styx in the live, interactive 3D map
Key facts
Radius
5.2 km
Orbit around Pluto
20.16 Earth days
Science
Physical
- Radius
- 5.2 km
- JPL / IAU mean radii; spacecraft-tracked GM where measured
Orbit around Pluto
- Distance from Pluto
- 43,200 km
- From JPL orbital elements
- Orbital period
- 20.2 days
- From JPL orbital elements
- Eccentricity
- 0.025
- From JPL orbital elements
- Inclination to the J2000 equator
- 0.00 °
- From JPL orbital elements
Rotation
- Rotation
- Chaotic — non-synchronous, tumbling with no fixed period like Pluto's other small moons (Showalter & Hamilton 2015). Not tidally locked.
Composition
- Bulk composition
- A tiny, irregular icy body; very little is known about it.
Radiation & temperature
- Insolation
- 0.000788 S⊕ · 1/1,269 of the sunlight Earth receives
- Computed from the distance to the Sun (inverse-square; Earth's sunlight = 1), before any atmosphere.
- Geometric albedo
- 0.50
- Estimated geometric albedo; data limited.
- Equilibrium temperature
- 39 K (-234 °C)
- Computed from albedo + distance from the Sun (airless black body); uses the geometric albedo as an estimate
Discovery & history
- By
- the Hubble Space Telescope (Mark Showalter and colleagues)
- Method
- Photographic plates
- Name
- Styx, the goddess and river that bounds the underworld in Greek myth.
Styx, found in Hubble images in 2012, is the smallest and faintest of Pluto's five known moons. Like its siblings it orbits the Pluto–Charon pair in near-resonance and tumbles chaotically. Beyond its discovery, essentially nothing is known about it.
Images
Images from open archives · credit shown per image