Kepler-142 d
Kepler-142 d is a mini-Neptune orbiting Kepler-142 in the constellation Cygnus. It lies about 1,790 light-years from Earth and was discovered in 2014 using the transit method.
How Big Is Kepler-142 d?
Kepler-142 d has a radius of 2.16 times that of Earth.
Is Kepler-142 d in the Habitable Zone?
Kepler-142 d orbits inside the inner edge of the habitable zone of Kepler-142. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-142: 0.956–2.251 AU (conservative: 1.210–2.134 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 ›
Orbit and Year Length
A year on Kepler-142 d — one full orbit around Kepler-142 — lasts 41.8 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.242 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-142 d Discovered?
Kepler-142 d was discovered in 2014 using the transit method, with observations from Kepler.
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 Kepler-142 d?
Kepler-142 d is 1,789.6 light-years (548.7 parsecs) from Earth. Light arriving here tonight left the planet about 1,790 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 31,496,960 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. Kepler-142 d scores 0.30, ranking #1,252 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-142
Kepler-142
- Surface temperature
- 5,790 K (Sun: 5,772 K)
- Radius
- 1.27 R☉
The Kepler-142 Planetary System
Kepler-142 d is one of 3 known planets in the Kepler-142 system. Its siblings:
- Kepler-142 b (Super Earth)
- Kepler-142 c (Mini Neptune)
Kepler-142 d — Complete Data
| Radius | 2.160 Earth radii (0.193 Jupiter radii) |
|---|---|
| Orbital period | 41.81 days |
| Orbital distance | 0.242 AU |
| Earth Similarity Index | 0.30 |
| Distance from Earth | 1,789.6 light-years (548.7 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2014 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-142 d
Is Kepler-142 d habitable?
No — Kepler-142 d orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-142 d?
Kepler-142 d is about 1,790 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 31,496,960 years to get there.
How big is Kepler-142 d compared to Earth?
Kepler-142 d has 2.16 times the radius of Earth.
How long is a year on Kepler-142 d?
One orbit around Kepler-142 takes 41.8 Earth days.
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