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Entering orbit…
Habitability
31/ 100
Extremely Harsh

Kepler-1251 b

BarrenExtremely Harsh2941 light years awayFound 2016

Kepler-1251 b, from the NASA Exoplanet Archive (found 2016). Measured: 4.04 Earth masses, 0.248 AU, a 5545 K G-type star. Composition inferred from a measured bulk density of 0.65x 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.

Host star

Kepler-1251

Type
G-type (Yellow (Sun-like))
Temperature
5,545 K
Radius
0.89 ☉
Mass
0.92 ☉
Known planets
1 (this one)
Luminosity
0.704 ☉

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.

Barren

Magnetic FieldHigh Activity
Why is this a Barren?Your planet has an unusual composition that doesn't fit standard classifications, or lacks the elements needed for complex geological processes.
Barren worlds can form from uncommon element combinations or may be remnants of larger bodies that lost their atmospheres and volatile materials.
Classification Criteria:
Composition doesn't match standard planet typesMass: 4.0x EarthTemperature: 550K
Further reading
The Little Book of ExoplanetsJoshua WinnHow these worlds are found, and what a measurement can honestly tell us.Exoplanets: Diamond Worlds, Super Earths, Pulsar PlanetsMichael Summers & James TrefilThe strange end of the catalogue — carbon worlds, molten rock, planets orbiting dead stars.Envisioning ExoplanetsMichael CarrollWhat these worlds might look like from the ground, painted from the same measurements this page renders.Imagined LifeJames Trefil & Michael SummersWhat could live on a world like this one: ice shells, supergravity, tidally locked twilight.
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Habitability ScoreExtremely Harsh
31
Contributing Factors
temperature15
Extremely hot - hostile to known life forms
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water34
Abundant water - boiling away, little would be retained
magnetic Field100
Magnetic field provides radiation protection
geology90
Active geology recycles nutrients and drives carbon cycle
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution

Physical Properties

Mass
4.04x Earth (2.41e+25 kg)
Radius
1.59x Earth (10,147 km)
This planet: 1.59× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.59x Earth (15.6 m/s²)
Surface Temperature
550 K (277 °C / 531 °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
0.25 AU (37.1 million km)
Orbital Period
45 days

Atmosphere

Thin CO₂ and nitrogen atmosphere

Elemental Composition

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

Surface Characteristics

Barren rocky surface with unusual elemental composition
The TerraForge exoplanet catalog: 5,572 real exoplanets run through the simulation, with a search field and rendered worlds grouped by type

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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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