Kepler-1222 b
Lava WorldUninhabitable1353 light years awayFound 2016
Kepler-1222 b, from the NASA Exoplanet Archive (found 2016). Measured: 0.418 Earth masses, 0.028 AU, a 5239 K G-type star. Composition inferred from a measured bulk density of 0.85x Earth's, which is rock and iron, with a day locked to its 1.9-day year, as anything orbiting this close would be.
Kepler-1222
- Type
- G-type (Yellow (Sun-like))
- Temperature
- 5,239 K
- Radius
- 0.8 ☉
- Mass
- 0.84 ☉
- Known planets
- 1 (this one)
- Luminosity
- 0.349 ☉
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.
Lava World
Extreme Activity
Why is this a Lava World?Your planet's proximity to its star (0.03 AU) results in extreme surface temperatures of 1277K.
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: 1277K (>1000K)
Habitability ScoreUninhabitable
Contributing Factors
temperature0
Inferno world - temperatures exceed all possibility of life
atmosphere10
No atmosphere - exposed to radiation and temperature extremes
water8
Limited water content - boiling away, little would be retained
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation65
Slow rotation - significant day/night temperature variations, but life can adapt
Physical Properties
Mass
0.42x Earth (2.50e+24 kg)Radius
0.75x Earth (4,764 km)Surface Gravity
0.75x Earth (7.3 m/s²)Surface Temperature
1,277 K (1,004 °C / 1,839 °F)Rotation Period
46.1 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.03 AU (4.19 million km)Orbital Period
2 daysTime Dilation
Clocks run 16.7 seconds per year slower than deep space — about 22 minutes over a lifetimeAtmosphere
Minimal - too hot to retain
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



