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Entering orbit…
Habitability
19/ 100
Uninhabitable

TOI-198 b

Rocky TerrestrialUninhabitable77 light years awayFound 2023

TOI-198 b, from the NASA Exoplanet Archive (found 2023). Measured: 3.17 Earth masses, 0.0675 AU, a 3801 K K-type star. Composition inferred from a measured bulk density of 1.26x Earth's, which is rock and iron, with a day locked to its 10.2-day year, as anything orbiting this close would be.

Host star

TOI-198

Type
K-type (Orange)
Spectral type
M0 V
Temperature
3,801 K
Radius
0.418 ☉
Mass
0.417 ☉
Known planets
1 (this one)
Luminosity
0.0328 ☉

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.

Rocky Terrestrial

High Activity
Why is this a Rocky Terrestrial?Your planet is dominated by silicate (25.0%) and iron (12.5%) content, forming a rocky terrestrial body.
Rocky terrestrial planets are primarily composed of silicate rocks and metals. They're the most common type of small planet in the universe.
Classification Criteria:
✓ Silicon: 25.0% + Iron: 12.5% + Magnesium: 3.8%✓ Mass: 3.2x Earth (terrestrial range)
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 ScoreUninhabitable
19
Contributing Factors
temperature15
Extremely hot - hostile to known life forms
atmosphere42
Nitrogen atmosphere provides protection but not breathable (partially stripped by slow rotation)
water33
Limited water content - likely as steam
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology90
Active geology recycles nutrients and drives carbon cycle
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides

Physical Properties

Mass
3.17x Earth (1.89e+25 kg)
Radius
1.47x Earth (9,359 km)
This planet: 1.47× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.47x Earth (14.4 m/s²)
Surface Temperature
462 K (189 °C / 372 °F)
Rotation Period
244.8 hours/day (slower than Earth)
This planet: 245 h/dayEarth: 24 h/day

Orbital Environment

Star Type
K-type (Orange)
Distance from Star
0.07 AU (10.1 million km)
Orbital Period
8 days

Atmosphere

Thin CO₂ and nitrogen atmosphere

Elemental Composition

O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%

Surface Characteristics

Rocky surface with impact craters, possible volcanic features
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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