TRAPPIST-1 h
Ice WorldUninhabitable40 light years awayFound 2017
TRAPPIST-1 h, from the NASA Exoplanet Archive (found 2017). Measured: 0.326 Earth masses, 0.0619 AU, a 2566 K M-type star. Composition inferred from a measured bulk density of 0.76x Earth's, which is rock and iron, with a day locked to its 18.8-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.
Ice World
None Activity
Why is this a Ice World?Your planet orbits at 0.06 AU from its star, resulting in frigid temperatures of 173K.
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: 0.06 AU (>3 AU) or Temperature <200K✓ Temperature: 173K✓ Water content: 34.4% for ice formation
Habitability ScoreUninhabitable
Contributing Factors
temperature20
Very cold - water frozen, challenging for life
atmosphere42
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
geology30
Geologically dead - no nutrient recycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - severe temperature swings between eternal day and night sides
Physical Properties
Mass
0.33x Earth (1.95e+24 kg)Radius
0.69x Earth (4,385 km)Surface Gravity
0.69x Earth (6.8 m/s²)Surface Temperature
173 K (-100 °C / -149 °F)Rotation Period
451.2 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.06 AU (9.26 million km)Orbital Period
10 daysAtmosphere
Thin nitrogen and methane atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



