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Entering orbit…
Habitability
30/ 100
Extremely Harsh

nylaka

by appleeater
0

Ice World

✦ startifire
Magnetic FieldLow Activity
Why is this a Ice World?Your planet orbits at 2.57 AU from its star, resulting in frigid temperatures of 140K.
Ice worlds form beyond the frost line where temperatures are low enough for water and other volatiles to freeze solid. They may have subsurface oceans beneath thick ice shells.
Classification Criteria:
✓ Distance: 2.57 AU (>3 AU) or Temperature <200K✓ Temperature: 140K✓ Water content: 29.9% for ice formation
Habitability ScoreExtremely Harsh
30
Contributing Factors
water60
Water present but mostly frozen
geology60
Some geological activity provides slow nutrient cycling
rotation30
Very slow rotation - severe temperature swings between eternal day and night sides
Organic Chemistry100
All CHNOPS elements present - building blocks of life (tidal pools cycle wet and dry - a boost for prebiotic chemistry)
atmosphere42
Nitrogen atmosphere provides protection but not breathable (partially stripped by slow rotation)
temperature20
Very cold - water frozen, challenging for life
magnetic Field100
Magnetic field provides radiation protection

Physical Properties

Mass
4.80x Earth (2.87e+25 kg)
Radius
1.69x Earth (10,747 km)
This planet: 1.69× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.69x Earth (16.5 m/s²)
Surface Temperature
140 K (-133 °C / -208 °F)
Rotation Period
25.0 hours/day (slower than Earth)
This planet: 25 h/dayEarth: 24 h/day

Orbital Environment

Star Type
K-type (Orange)
Distance from Star
2.57 AU (384 million km)
Orbital Period
4.92 years

Atmosphere

Thin nitrogen and methane atmosphere

Elemental Composition

O - Oxygen
24.7%
Si - Silicon
22.7%
Fe - Iron
16.5%

Surface Characteristics

Frozen surface covered in water ice, possible subsurface ocean if tidal heating present

Closest Real Exoplanet

GJ 1289 b88% similar
Orbiting GJ 1289
YoursGJ 1289 b
Mass4.80 × Earth6.27 × Earth
Radius2.07 × Earth2.38 × Earth
Density (composition)3.00 g/cm³2.56 g/cm³
Temperature139.8 K150.0 K
Starlight received0.06 × Earth0.08 × Earth
Star temperature4,450 K3,296 K
Discovered 2024 via radial velocity · 27 light-years awaySource: NASA Exoplanet Archive
Moons
Moon 1rings1.1% - 1.5 radii

Inside the Roche limit (2.80 planet radii): torn apart into a ring system.

Moon 2stable0.0089% - 7.1 radii

Small and distant: a quiet, stable companion.

Moon 3receding0.0063% - 100.0 radii

Outside the synchronous orbit: slowly receding, like Luna (~cm per year).

Moon 4merged2.5% - 100.0 radii

Merged with an adjacent moon: too close for both to hold a stable orbit.

+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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