Why is this a Volcanic World?Runaway tidal heating from its moons drives volcanism across a cold crust - the planet is kneaded like Io.
Resonant, close-in moons pump orbital eccentricity, and the resulting tidal flexing dissipates enormous heat in the interior. Only a fraction of the surface is molten at once, so the ground between the vents stays as cold as the orbit allows - Io's own equilibrium temperature is about 110 K.
Classification Criteria:
✓ Close-in moons in a resonant configuration✓ Tidal heat flux beyond the runaway threshold- The orbit is not what melted it: 15.80 AU, 70K equilibrium
Habitability
Destroyed — no longer habitable
Physical Properties
Mass
0.10x Earth (5.97e+23 kg)
Radius
0.46x Earth (2,957 km)
Surface Gravity
0.46x Earth (4.6 m/s²)
Surface Temperature
70 K (-203 °C / -334 °F)
Rotation Period
42.0 hours/day (slower than Earth)
Orbital Environment
Star Type
G-type (Yellow (Sun-like))
Distance from Star
15.80 AU (2.36 billion km)
Orbital Period
62.8 years
Atmosphere
Volcanic outgassing - sulfur compounds and vaporized rock
Elemental Composition
Si - Silicon
33.8%
Fe - Iron
24.6%
Mg - Magnesium
12.3%
Surface Characteristics
Runaway tidal heating drives volcanism across a cold crust - lava lakes and sulfur plains between frozen plains