Earth (4.54 billion years ago)
Lava World
Magnetic FieldExtreme Activity
Why is this a Lava World?A moon inside the synchronous orbit spiraled in and struck the planet. The impact remelted the surface into a global magma ocean.
Tidal decay drags close-in moons down over millions of years. A large enough impactor liquefies the crust, strips atmosphere, and resets the surface - whatever the orbit's temperature would otherwise allow.
Classification Criteria:
✓ Moon inside the synchronous orbit (tidal decay)✓ Impactor massive enough to remelt the crust- Orbit itself was fine: 0.99 AU, 279K equilibrium
Habitability ScoreExtremely Harsh
Contributing Factors
water20
Very dry - minimal water
geology50
Extreme volcanic activity may be hazardous (impact-resurfaced crust)
rotation60
Fast rotation - strong global wind patterns and weather systems, but manageable
Organic Chemistry20
Limited organic chemistry potential
atmosphere34
Nitrogen atmosphere provides protection but not breathable (atmosphere partially stripped by the moon impact)
temperature15
Optimal temperature range for liquid water and life (surface remelted by the moon impact - molten regardless of orbit)
magnetic Field100
Magnetic field provides radiation protection
Physical Properties
Mass
1.50x Earth (8.96e+24 kg)Radius
1.14x Earth (7293 km)Surface Gravity
1.14x Earth (11.2 m/s²)Surface Temperature
279 K (6 °C / 43 °F)Rotation Period
10.0 hours/day (faster than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.99 AU (148101892 million km)Atmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
Fe - Iron
26.7%
Si - Silicon
26.7%
Mg - Magnesium
20.0%
Surface Characteristics
Surface remelted by a catastrophic moon impact - a global magma ocean cooling into scarred rockMoons
Moon 1merged0.12% - 3.6 radii
Merged with an adjacent moon: too close for both to hold a stable orbit.
Moon 2crashed10% - 3.1 radii
Inside the synchronous orbit: tidal decay dragged it down - it struck the planet ages ago.