Kepler-1687 b
Rocky TerrestrialUninhabitable1359 light years awayFound 2020
Kepler-1687 b, from the NASA Exoplanet Archive (found 2020). Measured: 3.38 Earth masses, 0.0532 AU, a 4132 K K-type star. Composition inferred from a measured bulk density of 0.74x Earth's, which is rock and iron, with a day locked to its 5.8-day year, as anything orbiting this close would be.
Kepler-1687
- Type
- K-type (Orange)
- Temperature
- 4,132 K
- Radius
- 0.726 ☉
- Mass
- 0.65 ☉
- Known planets
- 1 (this one)
- Luminosity
- 0.138 ☉
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
High 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: 3.4x Earth (terrestrial range)
Habitability ScoreUninhabitable
Contributing Factors
temperature5
Scorching - hot enough to melt lead, though rock stays solid; no chance for life
atmosphere70
Nitrogen atmosphere provides protection but not breathable
water8
Limited water content - boiling away, little would be retained
magnetic Field30
No magnetic field - vulnerable to solar radiation
geology90
Active geology recycles nutrients and drives carbon cycle
Organic Chemistry80
Core organic elements (CHNO) present
rotation30
Very slow rotation - extreme temperature swings between eternal day and night sides
Physical Properties
Mass
3.38x Earth (2.02e+25 kg)Radius
1.50x Earth (9,561 km)Surface Gravity
1.50x Earth (14.7 m/s²)Surface Temperature
745 K (472 °C / 882 °F)Rotation Period
138.7 hours/day (slower than Earth)Orbital Environment
Star Type
K-type (Orange)Distance from Star
0.05 AU (7.96 million km)Orbital Period
5 daysTime Dilation
Clocks run 6.1 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%



