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
5/ 100
Uninhabitable
HD 219134 c rendered in TerraForge from its measured mass, orbit and star

HD 219134 c

Also written HD 219134c

Rocky Terrestrial21 light years awayFound 2015
Mass
4.36 × Earth
Radius
1.51 × Earth
Gravity
1.91 g
Surface (est.)
792 K
Year
6.8 days
From Earth
21.3 ly
Mass
4.36 × Earth
Radius
1.51 × Earth
Gravity
1.91 g
Surface (est.)
792 K
Year
6.8 days
From Earth
21.3 ly

HD 219134 system

Type
K-type (Orange)
Spectral type
K3 V
Temperature
4,699 K
Radius
0.778 ☉
Mass
0.81 ☉
Planets
7
Luminosity
0.265 ☉

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.

HD 219134 b0.039 AU4.7 M⊕
HD 219134 c0.065 AUYou are here4.4 M⊕
HD 219134 f0.15 AU7.3 M⊕
HD 219134 d0.24 AU16 M⊕
HD 219134 g0.38 AU11 M⊕
HD 219134 e2.56 AU71 M⊕
HD 219134 h3.11 AU108 M⊕
Habitable zone

Star and planets drawn to scale: the star is 56 times as wide as HD 219134 c, 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

HD 219134 c is one of two rocky planets known to cross in front of HD 219134, an orange dwarf star about 21 light-years away. It orbits every 6.76 days, just outside its sibling HD 219134 b. Being so close to the Sun and transiting a star bright enough to see without a telescope makes both planets valuable for comparison with rocky planets in our own solar system.

Surface. Rocky surface with impact craters, possible volcanic features

Rocky Terrestrial
Life unlikely — too hot for liquid waterHigh Activity
HD 219134 c 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: 4.4x Earth (terrestrial range)

Reading HD 219134 c’s atmosphere

Dominant elements: O, Si, Fe, N, C, HThis is what a telescope would measure while HD 219134 c 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.HD 219134 c sits about 21 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.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 ScoreUninhabitable
5
Contributing Factors
temperature3
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere70

Thin CO₂ and nitrogen atmosphere

Nitrogen atmosphere provides protection but not breathable
water8
Limited water content - boiling away, little would be retained
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 - days and nights each last several Earth days, bringing extreme temperature swings

Physical Properties

Mass
4.36x Earth (2.60e+25 kg)
Radius
1.63x Earth (10,408 km)
This planet: 1.63× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.63x Earth (16.0 m/s²)
Surface Temperature
792 K (519 °C / 966 °F)
Rotation Period
162.2 hours/day (slower than Earth)
This planet: 162 h/dayEarth: 24 h/day

Time Dilation

Clocks run 5.0 seconds per year slower than deep space — about 7 minutes over a lifetime

Elemental Composition

How TerraForge built this world

HD 219134 c, from the NASA Exoplanet Archive (found 2015). Measured: 4.36 Earth masses, 0.0653 AU, a 4699 K K-type star. Composition inferred from an estimated bulk density of 1.27x 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 6.8-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