Create your free account

Enter your email and we'll send a 6-digit code — no password needed.
We only keep your email and the username you choose. We never share or sell your email, and we don't send marketing — we use it only to email you a sign-in code. Learn more.
Entering orbit…
Habitability
58/ 100
Marginal

TOI-7166 b

Water WorldMarginal115 light years awayFound 2025

TOI-7166 b, from the NASA Exoplanet Archive (found 2025). Measured: 4.7 Earth masses, 0.0619 AU, a 3099 K M-type star. Composition inferred from a measured bulk density of 0.58x Earth's — too light for bare rock, so a large fraction of water and ice, with a day locked to its 12.9-day year, as anything orbiting this close would be.

Host star

TOI-7166

Type
M-type (Red Dwarf)
Spectral type
M4.5+/-0.5
Temperature
3,099 K
Radius
0.222 ☉
Mass
0.19 ☉
Known planets
1 (this one)
Luminosity
4.10e-3 ☉

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.

Water World

Life DetectedHigh Activity
Why is this a Water World?Your planet has abundant oxygen (41.2%) and hydrogen (17.6%), creating extensive water coverage while in the habitable temperature zone.
Water worlds have deep global oceans covering most or all of their surface. They form when planets have high water content and orbit in the habitable zone.
Classification Criteria:
✓ Oxygen: 41.2% + Hydrogen: 17.6% (water-forming elements)✓ Temperature: 304K (habitable range)✓ Distance: 0.06 AU (habitable zone)
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.
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 ScoreMarginal
58
Contributing Factors
temperature100
Optimal temperature range for liquid water and life
atmosphere60
Nitrogen-oxygen atmosphere - breathable and protective (partially stripped by slow rotation)
water100
Abundant water
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
4.70x Earth (2.81e+25 kg)
Radius
1.68x Earth (10,672 km)
This planet: 1.68× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.68x Earth (16.4 m/s²)
Surface Temperature
304 K (31 °C / 88 °F)
Rotation Period
309.6 hours/day (slower than Earth)
This planet: 310 h/dayEarth: 24 h/day

Orbital Environment

Star Type
M-type (Red Dwarf)
Distance from Star
0.06 AU (9.26 million km)
Orbital Period
10 days

Atmosphere

Nitrogen and oxygen with water vapor, mild greenhouse effect

Elemental Composition

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

Surface Characteristics

Vast oceans covering most of the surface, scattered islands or archipelagos

Habitability

✓ Conditions suitable for life detectedThis planet exhibits the necessary conditions to support biological processes, including stable temperatures, liquid water, and protective magnetic fields.
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.

Create your free account

Enter your email and we'll send a 6-digit code — no password needed.
We only keep your email and the username you choose. We never share or sell your email, and we don't send marketing — we use it only to email you a sign-in code. Learn more.

Send feedback

We're still building out the best experience we can — and we'd love your input. Tell us about features you enjoy, ideas you'd like to see, or pain points where something feels off, and we'll know where to look next.

Type