Kepler-138 d
A confirmed exoplanet orbiting Kepler-138.
Compared with Earth
- Size
- About 1.5 times Earth's width.
- Mass
- About 2.1 times Earth's mass.
- Temperature
- About 72 °C (161 °F) from starlight alone, against -18 °C (-1 °F) for Earth measured the same way.
- Starlight
- About 3.4 times the starlight Earth gets from the Sun.
- Year
- A year here lasts about 23 Earth days.
Planet
- Radius
- 1.51 × Earth
- Mass
- 2.1 × Earth
- Density
- 3.6 g/cm³
- Equilibrium temperature
- 345 K
- Starlight received
- 3.4 × Earth
- Orbital period
- 23.09 days
- Average distance from its star
- 0.1288 AU
Star
- Host star
- Kepler-138
- Spectral class
- M — red dwarf
- Surface temperature
- 3,841 K
- Radius
- 0.535 × Sun
- Mass
- 0.535 × Sun
- Age
- Unknown
System
- Distance from Earth
- 218.1 light-years (66.86 parsecs)
- Stars in system
- 1
- Known planets
- 4
Discovery
- Year
- 2014
- Method
- Transit
- Facility
- Kepler
Data from the NASA Exoplanet Archive, synced October 14, 2026.