Kepler-1668 b
Kepler-1668 b is a Neptune-like planet orbiting Kepler-1668 in the constellation Cygnus. It lies about 4,356 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is Kepler-1668 b?
Kepler-1668 b has a radius of 4.35 times that of Earth.
Is Kepler-1668 b in the Habitable Zone?
The position of Kepler-1668 b relative to the habitable zone of Kepler-1668 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-1668: 0.714–1.693 AU (conservative: 0.904–1.605 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-1668 b — one full orbit around Kepler-1668 — lasts 15.4 Earth days, shorter than Mercury's 88-day year.
How Was Kepler-1668 b Discovered?
Kepler-1668 b was discovered in 2020 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-1668 b?
Kepler-1668 b is 4,356.3 light-years (1,335.6 parsecs) from Earth. Light arriving here tonight left the planet about 4,356 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 76,670,880 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-1668 b scores 0.19, ranking #3,999 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Kepler-1668
Kepler-1668
- Surface temperature
- 5,542 K (Sun: 5,772 K)
- Mass
- 0.98 M☉
- Radius
- 1.02 R☉
- Luminosity
- 0.8797 L☉
Planetary System
Kepler-1668 b is the only planet known to orbit Kepler-1668 so far.
Kepler-1668 b — Complete Data
| Radius | 4.348 Earth radii (0.388 Jupiter radii) |
|---|---|
| Orbital period | 15.43 days |
| Earth Similarity Index | 0.19 |
| Distance from Earth | 4,356.3 light-years (1,335.6 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit |
| Discovery facility | Kepler |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2020-09-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-1668 b
Is Kepler-1668 b habitable?
Kepler-1668 b is not known to orbit within the habitable zone of Kepler-1668, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is Kepler-1668 b?
Kepler-1668 b is about 4,356 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 76,670,880 years to get there.
How big is Kepler-1668 b compared to Earth?
Kepler-1668 b has 4.35 times the radius of Earth.
How long is a year on Kepler-1668 b?
One orbit around Kepler-1668 takes 15.4 Earth days — short enough that 24 of its years would fit into one Earth year.
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