K2-38 c
Ice GiantUninhabitable629 light years awayFound 2016
K2-38 c, from the NASA Exoplanet Archive (found 2016). Measured: 8.3 Earth masses, 0.0951 AU, a 5731 K G-type star. Composition inferred from a measured bulk density of 0.69x Earth's — too light for bare rock, so a large fraction of water and ice, with a day locked to its 10.6-day year, as anything orbiting this close would be.
K2-38
- Type
- G-type (Yellow (Sun-like))
- Spectral type
- G2 V
- Temperature
- 5,731 K
- Radius
- 1.06 ☉
- Mass
- 1.03 ☉
- Known planets
- 2, including this one
- Luminosity
- 1.09 ☉
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 Giant
Extreme Activity
Why is this a Ice Giant?Your planet has moderate mass (8.3x Earth) with significant water, carbon, and nitrogen content, characteristic of ice giants.
Ice giants like Uranus and Neptune have icy interiors with thick atmospheres of hydrogen and helium, but not enough to be classified as gas giants.
Classification Criteria:
✓ Mass: 8.3x Earth (5-20x range)✓ Water/Carbon/Nitrogen rich composition
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere18
Hydrogen-rich atmosphere typical of gas giants (partially stripped by slow rotation)
water15
No solid surface — any water is locked in a supercritical mantle and hot ice, not oceans
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
8.30x Earth (4.96e+25 kg)Radius
2.02x Earth (12,899 km)Surface Gravity
2.02x Earth (19.9 m/s²)Surface Temperature
991 K (718 °C / 1,325 °F)Rotation Period
254.4 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.10 AU (14.2 million km)Orbital Period
11 daysAtmosphere
Hydrogen and helium with water, methane, and ammonia ices
Elemental Composition
O - Oxygen
41.2%
H - Hydrogen
17.6%
Si - Silicon
11.8%



