Barnard b
Rocky TerrestrialUninhabitable6 light years awayFound 2024
Barnard b, from the NASA Exoplanet Archive (found 2024). Measured: 0.299 Earth masses, 0.0229 AU, a 3195 K M-type star. Composition inferred from a measured bulk density of 0.80x Earth's, which is rock and iron, with a day locked to its 3.1-day year, as anything orbiting this close would be.
Barnard's star
- Type
- M-type (Red Dwarf)
- Spectral type
- M3.5-4 V
- Temperature
- 3,195 K
- Radius
- 0.185 ☉
- Mass
- 0.162 ☉
- Known planets
- 4, including this one
- Luminosity
- 3.55e-3 ☉
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
None 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: 0.3x Earth (terrestrial range)
Habitability ScoreUninhabitable
Contributing Factors
temperature15
Extremely hot - hostile to known life forms
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water20
Limited water content - likely as steam (low gravity lets water escape to space)
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology30
Geologically dead - no nutrient recycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation65
Slow rotation - significant day/night temperature variations, but life can adapt
Physical Properties
Mass
0.30x Earth (1.79e+24 kg)Radius
0.67x Earth (4,260 km)Surface Gravity
0.67x Earth (6.6 m/s²)Surface Temperature
452 K (179 °C / 354 °F)Rotation Period
75.6 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.02 AU (3.43 million km)Orbital Period
2 daysTime Dilation
Clocks run 6.1 seconds per year slower than deep space — about 8 minutes over a lifetimeAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



