Kepler-138 b

A confirmed exoplanet orbiting Kepler-138.

Compared with Earth

Size
About 64% of Earth's width.
Mass
About 7% of Earth's mass.
Temperature
About 179 °C (354 °F) from starlight alone, against -18 °C (-1 °F) for Earth measured the same way.
Starlight
About 9.9 times the starlight Earth gets from the Sun.
Year
A year here lasts about 10 Earth days.

Planet

Radius
0.64 × Earth
Mass
0.07 × Earth
Density
1.7 g/cm³
Equilibrium temperature
452 K
Starlight received
9.9 × Earth
Orbital period
10.31 days
Average distance from its star
0.0753 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.