GJ 433 d
Water WorldHighly Habitable30 light years awayFound 2020
GJ 433 d, from the NASA Exoplanet Archive (found 2020). Measured: 5.22 Earth masses, 0.178 AU, a 3461 K M-type star. Composition inferred from a measured bulk density of 0.53x Earth's — too light for bare rock, so a large fraction of water and ice, with an assumed 24-hour day — rotation cannot be measured for exoplanets.
GJ 433
- Type
- M-type (Red Dwarf)
- Spectral type
- M2V
- Temperature
- 3,461 K
- Radius
- 0.5 ☉
- Mass
- 0.48 ☉
- Known planets
- 3, including this one
- Luminosity
- 0.0200 ☉
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.
Water World
Life DetectedMagnetic FieldExtreme Activity
Why is this a Water World?Your planet has abundant oxygen (41.2%) and hydrogen (17.6%), creating extensive water coverage while in the habitable temperature zone.
Water worlds have deep global oceans covering most or all of their surface. They form when planets have high water content and orbit in the habitable zone.
Classification Criteria:
✓ Oxygen: 41.2% + Hydrogen: 17.6% (water-forming elements)✓ Temperature: 267K (habitable range)✓ Distance: 0.18 AU (habitable zone)
Habitability ScoreHighly Habitable
Contributing Factors
temperature70
Challenging but potentially habitable temperature
atmosphere100
Nitrogen-oxygen atmosphere - breathable and protective
water95
Abundant water - mostly frozen
magnetic Field100
Magnetic field provides radiation protection
geology40
Extreme volcanic activity may be hazardous
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution
Physical Properties
Mass
5.22x Earth (3.12e+25 kg)Radius
1.73x Earth (11,052 km)Surface Gravity
1.73x Earth (17.0 m/s²)Surface Temperature
267 K (-6 °C / 20 °F)Rotation Period
24.0 hours/dayOrbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.18 AU (26.6 million km)Orbital Period
50 daysAtmosphere
Nitrogen and oxygen with water vapor, mild greenhouse effect
Elemental Composition
O - Oxygen
41.2%
H - Hydrogen
17.6%
Si - Silicon
11.8%



