Kepler-1689 b
Rocky TerrestrialUninhabitable958 light years awayFound 2020
Kepler-1689 b, from the NASA Exoplanet Archive (found 2020). Measured: 0.799 Earth masses, 0.0784 AU, a 5731 K G-type star. Composition inferred from a measured bulk density of 0.94x Earth's, which is rock and iron, with a day locked to its 8.5-day year, as anything orbiting this close would be.
Kepler-1689
- Type
- G-type (Yellow (Sun-like))
- Temperature
- 5,731 K
- Radius
- 0.996 ☉
- Mass
- 1.02 ☉
- Known planets
- 1 (this one)
- Luminosity
- 0.965 ☉
Published by the NASA Exoplanet Archive. This world’s temperature and habitability score are computed from this star’s measured luminosity, not from a stand-in for its class.
Rocky Terrestrial
Low Activity
Why is this a Rocky Terrestrial?Your planet is dominated by silicate (25.0%) and iron (12.5%) content, forming a rocky terrestrial body.
Rocky terrestrial planets are primarily composed of silicate rocks and metals. They're the most common type of small planet in the universe.
Classification Criteria:
✓ Silicon: 25.0% + Iron: 12.5% + Magnesium: 3.8%✓ Mass: 0.8x Earth (terrestrial range)
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere42
Nitrogen atmosphere provides protection but not breathable (partially stripped by slow rotation)
water8
Limited water content - boiling away, little would be retained
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology60
Some geological activity provides slow nutrient cycling
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
0.80x Earth (4.77e+24 kg)Radius
0.93x Earth (5,912 km)Surface Gravity
0.93x Earth (9.1 m/s²)Surface Temperature
990 K (717 °C / 1,322 °F)Rotation Period
203.5 hours/day (slower than Earth)Orbital Environment
Star Type
G-type (Yellow (Sun-like))Distance from Star
0.08 AU (11.7 million km)Orbital Period
8 daysTime Dilation
Clocks run 6.0 seconds per year slower than deep space — about 8 minutes over a lifetimeAtmosphere
Thin CO₂ and nitrogen atmosphere
Elemental Composition
O - Oxygen
31.3%
Si - Silicon
25.0%
Fe - Iron
12.5%



