Kepler-298 d
Kepler-298 d is a mini-Neptune orbiting Kepler-298 in the constellation Draco. It lies about 1,690 light-years from Earth and was discovered in 2014 using the transit method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
How Big Is Kepler-298 d?
Kepler-298 d has a radius of 2.50 times that of Earth.
Is Kepler-298 d in the Habitable Zone?
Kepler-298 d orbits within the optimistic habitable zone of Kepler-298 — the broader region where liquid water might be possible under favorable atmospheric conditions.
Habitable zone of Kepler-298: 0.278–0.689 AU (conservative: 0.352–0.653 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-298 d — one full orbit around Kepler-298 — lasts 77.5 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.305 AU — closer to its star than Mercury is to the Sun.
How Was Kepler-298 d Discovered?
Kepler-298 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-298 d?
Kepler-298 d is 1,690.2 light-years (518.2 parsecs) from Earth. Light arriving here tonight left the planet about 1,690 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 29,747,520 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-298 d scores 0.62, ranking #120 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-298
Kepler-298
- Surface temperature
- 4,465 K (Sun: 5,772 K)
- Radius
- 0.58 R☉
The Kepler-298 Planetary System
Kepler-298 d is one of 3 known planets in the Kepler-298 system. Its siblings:
- Kepler-298 b (Super Earth)
- Kepler-298 c (Super Earth)
Kepler-298 d — Complete Data
| Radius | 2.500 Earth radii (0.223 Jupiter radii) |
|---|---|
| Orbital period | 77.47 days |
| Orbital distance | 0.305 AU |
| Earth Similarity Index | 0.62 |
| Distance from Earth | 1,690.2 light-years (518.2 parsecs) |
| Constellation | Draco |
| 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-298 d
Is Kepler-298 d habitable?
Kepler-298 d orbits within the habitable zone of Kepler-298, the region where liquid water could exist on a planet's surface. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is Kepler-298 d?
Kepler-298 d is about 1,690 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 29,747,520 years to get there.
How big is Kepler-298 d compared to Earth?
Kepler-298 d has 2.50 times the radius of Earth.
How long is a year on Kepler-298 d?
One orbit around Kepler-298 takes 77.5 Earth days.
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