L 98-59 b
Rocky TerrestrialUninhabitable35 light years awayFound 2019
L 98-59 b, from the NASA Exoplanet Archive (found 2019). Measured: 0.46 Earth masses, 0.0223 AU, a 3415 K M-type star. Composition inferred from a measured bulk density of 0.78x Earth's, which is rock and iron, with a day locked to its 2.3-day year, as anything orbiting this close would be.
L 98-59
- Type
- M-type (Red Dwarf)
- Spectral type
- M3 V
- Temperature
- 3,415 K
- Radius
- 0.316 ☉
- Mass
- 0.292 ☉
- Known planets
- 5, including this one
- Luminosity
- 0.0122 ☉
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
Low 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: 0.5x 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 Field30
No magnetic field - vulnerable to solar radiation
geology60
Some geological activity provides slow nutrient cycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation65
Slow rotation - significant day/night temperature variations, but life can adapt
Physical Properties
Mass
0.46x Earth (2.75e+24 kg)Radius
0.77x Earth (4,918 km)Surface Gravity
0.77x Earth (7.6 m/s²)Surface Temperature
625 K (351 °C / 665 °F)Rotation Period
54.0 hours/day (slower than Earth)Orbital Environment
Star Type
M-type (Red Dwarf)Distance from Star
0.02 AU (3.34 million km)Orbital Period
2 daysTime Dilation
Clocks run 6.3 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%



