K2-148 b
K2-148 b is a super-Earth orbiting K2-148 in the constellation Cetus. It lies about 406 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is K2-148 b?
K2-148 b has a radius of 1.33 times that of Earth.
Is K2-148 b in the Habitable Zone?
K2-148 b orbits inside the inner edge of the habitable zone of K2-148. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of K2-148: 0.257–0.649 AU (conservative: 0.326–0.615 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on K2-148 b
K2-148 b receives 48.80 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on K2-148 b — one full orbit around K2-148 — lasts 4.38 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.045 AU — closer to its star than Mercury is to the Sun.
How Was K2-148 b Discovered?
K2-148 b was discovered in 2018 using the transit method, with observations from K2.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is K2-148 b?
K2-148 b is 405.9 light-years (124.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1621. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,143,840 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. K2-148 b scores 0.31, ranking #1,102 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-148
K2-148 b belongs to a system of 2 stars; it orbits K2-148.
K2-148
- Surface temperature
- 4,079 K (Sun: 5,772 K)
- Mass
- 0.65 M☉
- Radius
- 0.63 R☉
- Luminosity
- 0.1010 L☉
The K2-148 Planetary System
K2-148 b is one of 3 known planets in the K2-148 system. Its siblings:
K2-148 b — Complete Data
| Radius | 1.330 Earth radii (0.119 Jupiter radii) |
|---|---|
| Orbital period | 4.38 days |
| Orbital distance | 0.045 AU |
| Stellar irradiation | 48.80× Earth |
| Earth Similarity Index | 0.31 |
| Distance from Earth | 405.9 light-years (124.5 parsecs) |
| Constellation | Cetus |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-02-01. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-148 b
Is K2-148 b habitable?
No — K2-148 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is K2-148 b?
K2-148 b is about 406 light-years from Earth in the constellation Cetus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,143,840 years to get there.
How big is K2-148 b compared to Earth?
K2-148 b has 1.33 times the radius of Earth.
How long is a year on K2-148 b?
One orbit around K2-148 takes 4.4 Earth days — short enough that 83 of its years would fit into one Earth year.
Explore K2-148 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
