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Habitability
0/ 100
Uninhabitable

Simalo

0

Carbon World

✦ Oan 8 5 system
Magnetic FieldModerate Activity
Why is this a Carbon World?Your planet's carbon (52.3%) outweighs its oxygen (0.0%), so the mineralogy flips from silicate rock to carbide - a graphite crust over a diamond mantle.
Carbon worlds form in carbon-rich disks where there isn't enough oxygen to bind it all into silicates. Instead carbon condenses directly into graphite, carbides, and - under pressure at depth - diamond. They form water-poor, so no life takes hold.
Classification Criteria:
✓ Carbon: 52.3% (>=20% required)✓ Carbon exceeds Oxygen: 52.3% > 0.0%✓ Mass: 1.8x Earth (<=8x hycean ceiling)
Habitability ScoreUninhabitable
0
Contributing Factors
water0
No water - the recipe has no hydrogen and oxygen to form it
geology90
Active geology recycles nutrients and drives carbon cycle
rotation30
Very slow rotation - severe temperature swings between eternal day and night sides
Organic Chemistry54
Carbon and hydrogen present - organic chemistry possible (tidal pools cycle wet and dry - a boost for prebiotic chemistry)
atmosphere24
Atmosphere present but composition not ideal for life (partially stripped by slow rotation)
temperature0
Near absolute zero - all molecular activity ceases, impossible for life
magnetic Field100
Magnetic field provides radiation protection

Physical Properties

Mass
1.80x Earth (1.07e+25 kg)
Radius
1.22x Earth (7,750 km)
This planet: 1.22× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.22x Earth (11.9 m/s²)
Surface Temperature
23 K (-250 °C / -419 °F)
Rotation Period
20.0 hours/day (faster than Earth)
This planet: 20 h/dayEarth: 24 h/day

Orbital Environment

Star Type
G-type (Yellow (Sun-like))
Distance from Star
150.00 AU (22.4 billion km)
Orbital Period
1,837 years

Atmosphere

Carbon monoxide and methane haze over a graphite surface

Elemental Composition

C - Carbon
52.3%
Fe - Iron
17.4%
Si - Silicon
17.4%

Surface Characteristics

Graphite plains and carbide ridges over a diamond mantle - a glittering coal-black world

Closest Real Exoplanet

EPIC 212624936 b73% similar
Orbiting EPIC 212624936
YoursEPIC 212624936 b
Mass1.80 × Earth1.87 × Earth
Radius1.32 × Earth1.20 × Earth
Density (composition)4.36 g/cm³5.96 g/cm³
Temperature22.7 K—
Starlight received0.00 × Earth—
Star temperature5,600 K5,765 K
Discovered 2021 via transit · 1,833 light-years awaySource: NASA Exoplanet Archive
Moons
Moon 1stable0.010% - 7.4 radii

Small and distant: a quiet, stable companion.

+4 chemistry: tidal pools cycle wet and dry - a boost for prebiotic chemistry
Surface views from three worlds: rocky ground under a ringed sky, a cloud deck, and a lit desert

New: Stand on Your World 🏔️

Every planet you build can now be seen from the ground. The terrain, the color of the sky, the weather and what hangs overhead are all read from the same numbers that shape the globe — so a thin-aired world gives you sunlit rock under a near-black sky crowded with stars, a runaway greenhouse seals you under an unbroken sulfur lid, and a gas giant leaves you in the cloud tops with nothing solid beneath you at all. If one of your moons wandered inside the Roche limit, what is left of it arcs overhead as rings.

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