Kepler-85 b
Kepler-85 b is a mini-Neptune orbiting Kepler-85 in the constellation Cygnus. It lies about 2,495 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is Kepler-85 b?
Kepler-85 b has a radius of 1.78 times that of Earth. Its mass is 1.8 times that of Earth, giving it a density of 1.82 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-85 b in the Habitable Zone?
The position of Kepler-85 b relative to the habitable zone of Kepler-85 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-85: 0.606–1.438 AU (conservative: 0.767–1.364 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-85 b — one full orbit around Kepler-85 — lasts 8.30 Earth days, shorter than Mercury's 88-day year. Its orbit is nearly circular (eccentricity 0.020).
How Was Kepler-85 b Discovered?
Kepler-85 b was discovered in 2012 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-85 b?
Kepler-85 b is 2,495.2 light-years (765.0 parsecs) from Earth. Light arriving here tonight left the planet about 2,495 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 43,915,520 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-85 b scores 0.27, ranking #2,642 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-85
Kepler-85
- Surface temperature
- 5,505 K (Sun: 5,772 K)
- Mass
- 0.93 M☉
- Radius
- 0.88 R☉
The Kepler-85 Planetary System
Kepler-85 b is one of 4 known planets in the Kepler-85 system. Its siblings:
- Kepler-85 c (Mini Neptune)
- Kepler-85 d (Terrestrial)
- Kepler-85 e (Super Earth)
Kepler-85 b — Complete Data
| Radius | 1.778 Earth radii (0.159 Jupiter radii) |
|---|---|
| Mass | 1.84 Earth masses (0.006 Jupiter masses) |
| Density | 1.82 g/cm³ (Earth: 5.51) |
| Orbital period | 8.30 days |
| Eccentricity | 0.020 |
| Earth Similarity Index | 0.27 |
| Distance from Earth | 2,495.2 light-years (765.0 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2024-06-10. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-85 b
Is Kepler-85 b habitable?
Kepler-85 b is not known to orbit within the habitable zone of Kepler-85, and as a mini-Neptune it is an unlikely candidate for life as we know it.
How far away is Kepler-85 b?
Kepler-85 b is about 2,495 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 43,915,520 years to get there.
How big is Kepler-85 b compared to Earth?
Kepler-85 b has 1.78 times the radius of Earth and about 1.8 times its mass.
How long is a year on Kepler-85 b?
One orbit around Kepler-85 takes 8.3 Earth days — short enough that 44 of its years would fit into one Earth year.
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