TRAPPIST-1 b
Rocky TerrestrialExtremely Harsh40 light years awayFound 2016
TRAPPIST-1 b, from the NASA Exoplanet Archive (found 2016). Measured: 1.37 Earth masses, 0.0115 AU, a 2566 K M-type star. Composition inferred from a measured bulk density of 0.98x Earth's, which is rock and iron, with a day locked to its 1.5-day year, as anything orbiting this close would be.
TRAPPIST-1
- Type
- M-type (Red Dwarf)
- Spectral type
- M8.0 V
- Temperature
- 2,566 K
- Radius
- 0.119 ☉
- Mass
- 0.0898 ☉
- Known planets
- 7, including this one
- Luminosity
- 5.53e-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.
Rocky Terrestrial
Magnetic FieldModerate Activity
Why is this a Rocky Terrestrial?Your planet 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: 1.4x Earth (terrestrial range)
Habitability ScoreExtremely Harsh
Contributing Factors
temperature15
Extremely hot - hostile to known life forms
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water44
Limited water content - likely as steam
magnetic Field100
Magnetic field provides radiation protection
geology90
Active geology recycles nutrients and drives carbon cycle
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution
Physical Properties
Mass
1.37x Earth (8.18e+24 kg)Radius
1.11x Earth (7,076 km)Surface Gravity
1.11x Earth (10.9 m/s²)Surface Temperature
403 K (130 °C / 266 °F)Rotation Period
36.2 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.01 AU (1.72 million km)Orbital Period
1 dayTime Dilation
Clocks run 12.2 seconds per year slower than deep space — about 16 minutes over a lifetimeAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



