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Entering orbit…
Habitability
59/ 100
Marginal

tau Cet f

Ice WorldMarginal12 light years awayFound 2017

tau Cet f, from the NASA Exoplanet Archive (found 2017). Measured: 3.93 Earth masses, 1.33 AU, a 5310 K G-type star. Composition inferred from a measured bulk density of 0.66x 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

tau Cet

Type
G-type (Yellow (Sun-like))
Spectral type
G8.5V
Temperature
5,310 K
Radius
0.83 ☉
Mass
0.783 ☉
Known planets
3, including this one
Luminosity
0.495 ☉

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.

Ice World

Magnetic FieldLow Activity
Why is this a Ice World?Your planet orbits at 1.33 AU from its star, resulting in frigid temperatures of 218K.
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: 1.33 AU (>3 AU) or Temperature <200K✓ Temperature: 218K✓ Water content: 50.0% for ice formation
Further reading
Imagined LifeJames Trefil & Michael SummersWhat could live on a world like this one: ice shells, supergravity, tidally locked twilight.Envisioning ExoplanetsMichael CarrollWhat these worlds might look like from the ground, painted from the same measurements this page renders.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.
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Habitability ScoreMarginal
59
Contributing Factors
temperature40
Extreme temperature - very difficult for life
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water54
Abundant water - frozen solid, no liquid phase at this temperature
magnetic Field100
Magnetic field provides radiation protection
geology60
Some geological activity provides slow nutrient cycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution

Physical Properties

Mass
3.93x Earth (2.35e+25 kg)
Radius
1.58x Earth (10,054 km)
This planet: 1.58× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.58x Earth (15.5 m/s²)
Surface Temperature
218 K (-56 °C / -68 °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
1.33 AU (199 million km)
Orbital Period
1.53 years

Atmosphere

Thin nitrogen and methane atmosphere

Elemental Composition

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

Surface Characteristics

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