Kepler-138 c

A confirmed exoplanet orbiting Kepler-138.

Compared with Earth

Size
About 1.5 times Earth's width.
Mass
About 2.3 times Earth's mass.
Temperature
About 137 °C (278 °F) from starlight alone, against -18 °C (-1 °F) for Earth measured the same way.
Starlight
About 6.8 times the starlight Earth gets from the Sun.
Year
A year here lasts about 14 Earth days.

Planet

Radius
1.51 × Earth
Mass
2.3 × Earth
Density
3.6 g/cm³
Equilibrium temperature
410 K
Starlight received
6.8 × Earth
Orbital period
13.78 days
Average distance from its star
0.0913 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.