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Habitability
40/ 100
Marginal

The Antratian System

0

Ice Giant

Magnetic FieldExtreme Activity
Why is this a Ice Giant?Your planet has moderate mass (242.0x Earth) with significant water, carbon, and nitrogen content, characteristic of ice giants.
Ice giants like Uranus and Neptune have icy interiors with thick atmospheres of hydrogen and helium, but not enough to be classified as gas giants.
Classification Criteria:
✓ Mass: 242.0x Earth (5-20x range)✓ Water/Carbon/Nitrogen rich composition
Habitability ScoreMarginal
40
Contributing Factors
water15
No solid surface — any water is locked in a supercritical mantle and hot ice, not oceans
geology40
Extreme volcanic activity may be hazardous
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Organic Chemistry84
Core organic elements (CHNO) present (tidal pools cycle wet and dry - a boost for prebiotic chemistry)
atmosphere30
Hydrogen-rich atmosphere typical of gas giants
temperature100
Optimal temperature range for liquid water and life
magnetic Field100
Magnetic field provides radiation protection

Physical Properties

Mass
242.00x Earth (1.45e+27 kg)
Radius
6.23x Earth (39,702 km)
This planet: 6.23× Earth radiusEarth: 1× (baseline)
Surface Gravity
6.23x Earth (61.1 m/s²)
Surface Temperature
282 K (9 °C / 48 °F)
Rotation Period
24.0 hours/day
This planet: 24 h/dayEarth: 24 h/day

Orbital Environment

Star Type
G-type (Yellow (Sun-like))
Distance from Star
1.00 AU (150 million km)
Orbital Period
1.00 years

Atmosphere

Hydrogen and helium with water, methane, and ammonia ices

Elemental Composition

O - Oxygen
31.3%
Si - Silicon
25.0%
N - Nitrogen
12.5%

Surface Characteristics

No solid surface - a deep volatile envelope over a supercritical water mantle and hot-ice interior

Closest Real Exoplanet

HD 100777 b78% similar
Orbiting HD 100777
YoursHD 100777 b
Mass242.0 × Earth391.0 × Earth
Radius9.41 × Earth13.7 × Earth
Density (composition)1.60 g/cm³0.84 g/cm³
Temperature282.1 K264.0 K
Starlight received1.00 × Earth0.93 × Earth
Star temperature5,600 K5,533 K
Discovered 2007 via radial velocity · 161 light-years awaySource: NASA Exoplanet Archive
Moons
Moon 1rings0.010% - 2.8 radii

Inside the synchronous orbit: it spiraled inward and was torn apart at the Roche limit (Phobos's fate).

Moon 2stable0.010% - 8.6 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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