Entering orbit…
| Yours | Kepler-138 b | |
|---|---|---|
| Mass | 0.10 × Earth | 0.07 × Earth |
| Radius | 0.54 × Earth | 0.64 × Earth |
| Density (composition) | 3.42 g/cm³ | 1.47 g/cm³ |
| Temperature | 439.6 K | 452.0 K |
| Starlight received | 6.25 × Earth | 9.90 × Earth |
| Star temperature | 5,600 K | 3,841 K |
Outside the synchronous orbit: slowly receding, like Luna (~cm per year).
Tidal braking locked the planet to its moon: one face forever moonward.