TOI-540 b
Rocky TerrestrialUninhabitable46 light years awayFound 2020
TOI-540 b, from the NASA Exoplanet Archive (found 2020). Measured: 0.674 Earth masses, 0.0122 AU, a 3216 K M-type star. Composition inferred from a measured bulk density of 0.92x Earth's, which is rock and iron, with a day locked to its 1.2-day year, as anything orbiting this close would be.
TOI-540
- Type
- M-type (Red Dwarf)
- Spectral type
- M V
- Temperature
- 3,216 K
- Radius
- 0.19 ☉
- Mass
- 0.159 ☉
- Known planets
- 1 (this one)
- Luminosity
- 3.46e-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
Magnetic FieldLow 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: 0.7x Earth (terrestrial range)
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water8
Limited water content - boiling away, little would be retained
magnetic Field100
Magnetic field provides radiation protection
geology60
Some geological activity provides slow nutrient cycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation100
Optimal rotation period - balanced day/night cycle, moderate weather, and good heat distribution
Physical Properties
Mass
0.67x Earth (4.03e+24 kg)Radius
0.88x Earth (5,586 km)Surface Gravity
0.88x Earth (8.6 m/s²)Surface Temperature
617 K (344 °C / 652 °F)Rotation Period
29.8 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.01 AU (1.83 million km)Orbital Period
1 dayTime Dilation
Clocks run 11.5 seconds per year slower than deep space — about 15 minutes over a lifetimeAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



