K2-72 b
Rocky TerrestrialUninhabitable216 light years awayFound 2016
K2-72 b, from the NASA Exoplanet Archive (found 2016). Measured: 1.28 Earth masses, 0.04 AU, a 3360 K M-type star. Composition inferred from a measured bulk density of 1.02x Earth's, which is rock and iron, with a day locked to its 5.6-day year, as anything orbiting this close would be.
K2-72
- Type
- M-type (Red Dwarf)
- Temperature
- 3,360 K
- Radius
- 0.331 ☉
- Mass
- 0.271 ☉
- Known planets
- 4, including this one
- Luminosity
- 0.0146 ☉
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
Moderate 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: 1.3x Earth (terrestrial range)
Habitability ScoreUninhabitable
Contributing Factors
temperature15
Extremely hot - hostile to known life forms
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water28
Limited water content - likely as steam
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 - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
1.28x Earth (7.64e+24 kg)Radius
1.09x Earth (6,917 km)Surface Gravity
1.09x Earth (10.7 m/s²)Surface Temperature
490 K (217 °C / 423 °F)Rotation Period
133.9 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.04 AU (5.98 million km)Orbital Period
5 daysAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



