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Entering orbit…
Habitability
0/ 100
Uninhabitable
GJ 806 b rendered in TerraForge from its measured mass, orbit and star

GJ 806 b

Also written GJ 806b

Lava World39 light years awayFound 2023
Mass
1.90 × Earth
Radius
1.33 × Earth
Gravity
1.07 g
Surface (est.)
1,001 K
Year
22.2 hrs
From Earth
39.1 ly
Mass
1.90 × Earth
Radius
1.33 × Earth
Gravity
1.07 g
Surface (est.)
1,001 K
Year
22.2 hrs
From Earth
39.1 ly

GJ 806 system

Type
M-type (Red Dwarf)
Spectral type
M1.5 V
Temperature
3,600 K
Radius
0.414 ☉
Mass
0.413 ☉
Planets
2
Luminosity
0.0260 ☉

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.

Habitable zone

Star and planets drawn to scale: the star is 34 times as wide as GJ 806 b, so only its edge is in view. Orbits spaced as in the star system view.

GJ 806 b, from the NASA Exoplanet Archive (found 2023). Measured: 1.9 Earth masses, 0.0141 AU, a 3600 K M-type star. Composition inferred from a measured bulk density of 0.81x Earth's at this size, suggesting roughly 23% water/ice by mass, with a day locked to its 0.9-day year, as anything orbiting this close would be.

Surface. Molten surface with lava flows, volcanic activity everywhere

Lava World
Life unlikely — too hot for liquid waterMagnetic FieldExtreme Activity
GJ 806 b's proximity to its star (0.01 AU) results in extreme surface temperatures of 1001K.
Lava worlds orbit so close to their stars that rocky surfaces melt into oceans of molten rock. Recent planet formation can also create temporary lava worlds.
Classification Criteria:
✓ Temperature: 1001K (>1000K)

Reading GJ 806 b’s atmosphere

Dominant elements: O, Si, H, Fe, N, CThis is what a telescope would measure while GJ 806 b 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.GJ 806 b sits about 39 light-years away, found by the transit 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.
Habitability ScoreUninhabitable
0
Contributing Factors
temperature0
Inferno world - temperatures exceed all possibility of life
atmosphere40

Vaporized rock and metals

Atmosphere present but composition not ideal for life
water15
Abundant water - boiling away, little would be retained
magnetic Field100
Magnetic field provides radiation protection
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution

Physical Properties

Mass
1.90x Earth (1.13e+25 kg)
Radius
1.24x Earth (7,891 km)
This planet: 1.24× Earth radiusEarth: 1× (baseline)
Surface Gravity
1.24x Earth (12.2 m/s²)
Surface Temperature
1,001 K (728 °C / 1,342 °F)
Rotation Period
22.2 hours/day (faster than Earth)
This planet: 22 h/dayEarth: 24 h/day

Time Dilation

Clocks run 9.9 seconds per year slower than deep space — about 13 minutes over a lifetime

Elemental Composition

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.

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