Kepler-30 b
Kepler-30 b is a puffy low-density planet orbiting Kepler-30 in the constellation Lyra. It lies about 2,982 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is Kepler-30 b?
Kepler-30 b has a radius of 3.90 times that of Earth. Its mass is 11.3 times that of Earth, giving it a density of 1.02 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Kepler-30 b in the Habitable Zone?
Kepler-30 b orbits inside the inner edge of the habitable zone of Kepler-30. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Kepler-30: 0.656–1.559 AU (conservative: 0.831–1.478 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-30 b — one full orbit around Kepler-30 — lasts 29.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.180 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.042).
How Was Kepler-30 b Discovered?
Kepler-30 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-30 b?
Kepler-30 b is 2,981.8 light-years (914.2 parsecs) from Earth. Light arriving here tonight left the planet about 2,982 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 52,479,680 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-30 b scores 0.24, ranking #3,280 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-30
Kepler-30
- Surface temperature
- 5,498 K (Sun: 5,772 K)
- Mass
- 0.99 M☉
- Radius
- 0.95 R☉
- Age
- 2.0 billion years (Sun: 4.6)
The Kepler-30 Planetary System
Kepler-30 b is one of 3 known planets in the Kepler-30 system. Its siblings:
- Kepler-30 c (Cold Gas Giant)
- Kepler-30 d (Cold Gas Giant)
Kepler-30 b — Complete Data
| Radius | 3.900 Earth radii (0.348 Jupiter radii) |
|---|---|
| Mass | 11.30 Earth masses (0.036 Jupiter masses) |
| Density | 1.02 g/cm³ (Earth: 5.51) |
| Orbital period | 29.33 days |
| Orbital distance | 0.180 AU |
| Eccentricity | 0.042 |
| Earth Similarity Index | 0.24 |
| Distance from Earth | 2,981.8 light-years (914.2 parsecs) |
| Constellation | Lyra |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2023-11-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-30 b
Is Kepler-30 b habitable?
No — Kepler-30 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Kepler-30 b?
Kepler-30 b is about 2,982 light-years from Earth in the constellation Lyra. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 52,479,680 years to get there.
How big is Kepler-30 b compared to Earth?
Kepler-30 b has 3.90 times the radius of Earth and about 11.3 times its mass.
How long is a year on Kepler-30 b?
One orbit around Kepler-30 takes 29.3 Earth days — short enough that 12 of its years would fit into one Earth year.
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