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Entering orbit…
Habitability
0/ 100
Uninhabitable

Kepler-939 b

Lava WorldUninhabitable6813 light years awayFound 2016

Kepler-939 b, from the NASA Exoplanet Archive (found 2016). Measured: 3.71 Earth masses, 0.115 AU, a 5471 K G-type star. Composition inferred from a measured bulk density of 0.69x Earth's — too light for bare rock, so a large fraction of water and ice, with an assumed 24-hour day — rotation cannot be measured for exoplanets. Note: TerraForge comes out at 1105 K against the archive's 692 K, because it models stars by spectral class, and Kepler-939 is not an average G-type.

Host star

Kepler-939

Type
G-type (Yellow (Sun-like))
Temperature
5,471 K
Radius
0.85 ☉
Mass
0.88 ☉
Known planets
1 (this one)
Luminosity
2.46 ☉

Published by the NASA Exoplanet Archive. This world’s temperature and habitability score are computed from this star’s measured luminosity, not from a stand-in for its class.

Lava World

Magnetic FieldExtreme Activity
Why is this a Lava World?Your planet's proximity to its star (0.12 AU) results in extreme surface temperatures of 1105K.
Lava worlds orbit so close to their stars that rocky surfaces melt into oceans of molten rock. Recent planet formation can also create temporary lava worlds.
Classification Criteria:
✓ Temperature: 1105K (>1000K)
Further reading
Exoplanets: Diamond Worlds, Super Earths, Pulsar PlanetsMichael Summers & James TrefilThe strange end of the catalogue — carbon worlds, molten rock, planets orbiting dead stars.Imagined LifeJames Trefil & Michael SummersWhat could live on a world like this one: ice shells, supergravity, tidally locked twilight.The Little Book of ExoplanetsJoshua WinnHow these worlds are found, and what a measurement can honestly tell us.Envisioning ExoplanetsMichael CarrollWhat these worlds might look like from the ground, painted from the same measurements this page renders.
As an Amazon Associate I earn from qualifying purchases — if you buy through these links, TerraForge may receive a small commission at no extra cost to you.
Habitability ScoreUninhabitable
0
Contributing Factors
temperature0
Inferno world - temperatures exceed all possibility of life
atmosphere40
Atmosphere present but composition not ideal for life
water15
Abundant water - boiling away, little would be retained
magnetic Field100
Magnetic field provides radiation protection
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution

Physical Properties

Mass
3.71x Earth (2.22e+25 kg)
Radius
1.55x Earth (9,863 km)
This planet: 1.55× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.55x Earth (15.2 m/s²)
Surface Temperature
1,105 K (832 °C / 1,529 °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
0.12 AU (17.2 million km)
Orbital Period
14 days

Atmosphere

Vaporized rock and metals

Elemental Composition

O - Oxygen
41.2%
H - Hydrogen
17.6%
Si - Silicon
11.8%

Surface Characteristics

Molten surface with lava flows, volcanic activity everywhere
The TerraForge exoplanet catalog: 5,572 real exoplanets run through the simulation, with a search field and rendered worlds grouped by type

New: The Exoplanet Catalog 🔭

Every confirmed planet NASA has measured well enough to build — 5,572 of them — is now in here, and none of them arrived with a label. Their real mass, radius, orbit and star go through the same simulation that runs everything you make, and it decides what each one is: gas giant, lava world, ocean, ice. Sixteen come out Earth-like. Find TRAPPIST-1e, stand on its surface, and see what a red dwarf's light actually looks like from the ground.

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