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. Read our privacy policy.
Entering orbit…
Habitability
10/ 100
Uninhabitable
Teegarden's Star d rendered in TerraForge from its measured mass, orbit and star

Teegarden's Star d

Also written Teegarden's Stard

Ice World12 light years awayFound 2024
Mass
0.82 × Earth
Radius
0.95 × Earth
Gravity
0.90 g
Surface (est.)
164 K
Year
26.1 days
From Earth
12.5 ly
Mass
0.82 × Earth
Radius
0.95 × Earth
Gravity
0.90 g
Surface (est.)
164 K
Year
26.1 days
From Earth
12.5 ly

Teegarden's Star system

Type
M-type (Red Dwarf)
Spectral type
M7.0 V
Temperature
3,034 K
Radius
0.12 ☉
Mass
0.097 ☉
Planets
3
Luminosity
7.22e-4 ☉

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.

Teegarden's Star b0.026 AU1.2 M⊕
Teegarden's Star c0.045 AU1.1 M⊕
Teegarden's Star d0.079 AUYou are here0.8 M⊕
Habitable zone

Star and planets drawn to scale: the star is 14 times as wide as Teegarden's Star d, so only its edge is in view. Orbits spaced as in the star system view.

Estimated: this planet doesn't transit its star, so its size is inferred, not measured

Teegarden's Star d is the third and outermost known planet of Teegarden's Star, a very small, dim red dwarf about 12.5 light-years away. It was announced in 2024, five years after its two inner siblings, Teegarden's Star b and c. It orbits every 26.1 days and has a minimum mass of about 0.82 Earth masses, a little less than Earth's.

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

Ice World
Life unlikely — too cold for liquid waterModerate Activity
Teegarden's Star d orbits at 0.08 AU from its star, resulting in frigid temperatures of 164K.
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: 0.08 AU (>3 AU) or Temperature <200K✓ Temperature: 164K✓ Water content: 34.4% for ice formation

Reading Teegarden's Star d’s atmosphere

Dominant elements: O, Si, Fe, N, C, HThis is what a telescope would measure while Teegarden's Star d crosses in front of its star: starlight passes through the atmosphere and spreads into a rainbow band. Each dark line marks a wavelength the atmosphere absorbed.Every element absorbs its own signature wavelengths — hydrogen always darkens the same two spots, calcium another pair, and so on. Astronomers match the lines in a real spectrum against a library of these signatures to say what an atmosphere is made of, light-years away, without ever visiting. A deeper line generally means more of that element is present.Teegarden's Star d sits about 12 light-years away, found by the radial velocity method. Most catalogued distances trace back to parallax: as Earth orbits the Sun, a nearby star appears to shift very slightly against the distant background stars, and the size of that shift gives its distance directly.
Further reading
ExoplanetsSara Seager (editor)The field's standard reference: how planets are found, how they form, and what their atmospheres are made of.The Planet FactoryElizabeth TaskerHow planets are made, and why so few of them come out like Earth.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.
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
10
Contributing Factors
temperature16
Very cold - water frozen, challenging for life
atmosphere28

Thin nitrogen and methane atmosphere

Nitrogen atmosphere provides protection but not breathable (partially stripped by slow rotation)
water11
Limited water content - frozen solid, no liquid phase at this temperature
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
rotation10
Near tidally locked - one hemisphere perpetually scorched, other frozen, narrow habitable twilight zone only

Physical Properties

Mass
0.82x Earth (4.90e+24 kg)
Radius
0.94x Earth (5,963 km)
This planet: 0.94× Earth radiusEarth: 1× (baseline)
Surface Gravity
0.94x Earth (9.2 m/s²)
Surface Temperature
164 K (-109 °C / -164 °F)
Rotation Period
626.4 hours/day (slower than Earth)
This planet: 626 h/dayEarth: 24 h/day

Elemental Composition

How TerraForge built this world

Teegarden's Star d, from the NASA Exoplanet Archive (found 2024). Measured: 0.82 Earth masses, 0.0791 AU, a 3034 K M-type star. Composition inferred from an estimated bulk density of 0.94x Earth's, modeled rather than measured since this isn't a transiting planet — the radius is the archive's estimate, so it can't settle how much water there is; read as rock and iron, with a day locked to its 26.1-day year, as anything orbiting this close would be.

A dark ringed planet hanging over the horizon of a rocky moon, its rings lit by a distant sun

New: Stand on Your Moons 🌒

A planet's surface view isn't the only ground any more. Press the surface button on a planet with moons and it asks where to stand: the planet itself, or any moon still in orbit, each tagged with what it became — ocean, ice, carbon, volcanic. Every moon gets its own ground and sky from its own physics: airless rock under a black sky, ice cracked by geysers over a hidden sea, sulfur plains shaking with eruptions, or orange haze you can't see the sun through. And hanging over the horizon, there's the planet you built.

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. Read our privacy policy.

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
Idea
Bug
Pain point
Other