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Entering orbit…
Habitability
30/ 100
Extremely Harsh

Lýra

by Polemos
0

Ice Giant

✦ Ílios
Extreme Activity
Why is this a Ice Giant?Your planet has moderate mass (10.0x 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: 10.0x Earth (5-20x range)✓ Water/Carbon/Nitrogen rich composition
Habitability ScoreExtremely Harsh
30
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
rotation10
Near tidally locked - one hemisphere perpetually scorched, other frozen, narrow habitable twilight zone only
Organic Chemistry100
All CHNOPS elements present - building blocks of life
atmosphere12
Hydrogen-rich atmosphere typical of gas giants (partially stripped by slow rotation)
temperature15
Extremely hot - hostile to known life forms
magnetic Field30
No magnetic field - vulnerable to solar radiation

Physical Properties

Mass
10.00x Earth (5.97e+25 kg)
Radius
2.15x Earth (13,726 km)
This planet: 2.15× Earth radiusEarth: 1× (baseline)
Surface Gravity
2.15x Earth (21.1 m/s²)
Surface Temperature
529 K (256 °C / 492 °F)
Rotation Period
528.0 hours/day (slower than Earth)
This planet: 528 h/dayEarth: 24 h/day

Orbital Environment

Star Type
K-type (Orange)
Distance from Star
0.18 AU (26.9 million km)
Orbital Period
33 days

Atmosphere

Hydrogen and helium with water, methane, and ammonia ices

Elemental Composition

O - Oxygen
25.0%
Si - Silicon
22.9%
Fe - Iron
16.7%

Surface Characteristics

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

Closest Real Exoplanet

HD 164922 e95% similar
Orbiting HD 164922
YoursHD 164922 e
Mass10.0 × Earth10.5 × Earth
Radius3.25 × Earth3.23 × Earth
Density (composition)1.60 g/cm³1.72 g/cm³
Temperature528.7 K544.0 K
Starlight received12.3 × Earth13.4 × Earth
Star temperature4,450 K5,393 K
Discovered 2021 via radial velocity · 72 light-years awaySource: NASA Exoplanet Archive
Moons
Moon 1rings0.00010% - 7.1 radii

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

Moon 2receding0.071% - 60.4 radii

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

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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