K2-72 c
Rocky TerrestrialExtremely Harsh216 light years awayFound 2016
K2-72 c, from the NASA Exoplanet Archive (found 2016). Measured: 1.65 Earth masses, 0.078 AU, a 3360 K M-type star. Composition inferred from a measured bulk density of 1.06x Earth's, which is rock and iron, with a day locked to its 15.2-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: 1.6x Earth (terrestrial range)
Habitability ScoreExtremely Harsh
Contributing Factors
temperature40
Extreme temperature - very difficult for life
atmosphere42
Nitrogen atmosphere provides protection but not breathable (partially stripped by slow rotation)
water50
Limited water content
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
1.65x Earth (9.85e+24 kg)Radius
1.18x Earth (7,528 km)Surface Gravity
1.18x Earth (11.6 m/s²)Surface Temperature
351 K (78 °C / 172 °F)Rotation Period
364.8 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.08 AU (11.7 million km)Orbital Period
15 daysAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



