Low-mass, low-density worlds
Kepler-138, also known as KOI-314, is a red dwarf star about 219 light-years away in the constellation Lyra, which hosts four known planets. Kepler-138 c & d are both about 1.5 times the size of Earth; they were originally estimated to have very different masses and densities, but were found in 2022 to be similarly low-density, volatile-rich "ocean worlds". Kepler-138 b is the second-least massive exoplanet with a measured mass (after Draugr), between that of Mars and Mercury, and also has a low density, though it's certainly rocky given how small it is. Kepler-138 e is almost half the mass of Earth; it was discovered through transit timing variations of the other planets, and is the least massive exoplanet found by this method.
The textures for the star and planet b, and the surface texture for planet e, have been taken from the addon for this system by adios.
kepler138.zip- (19.03 MiB) Downloaded 396 times
- The planets of Kepler-138
Kepler-22 & 62
Kepler's first habitable zone planets
Kepler-22 b, Kepler-62 e, and Kepler-62 f were the first planets in the habitable zone discovered by the Kepler mission. In particular, Kepler-62 f (announced 10 years ago this month) is small enough that it most likely has a rocky composition, and can be considered the first good candidate for a potentially habitable exoplanet. On the other hand, Kepler-22 b is just over twice the size of Earth, and it was realized even at the time of discovery that it was unlikely to have a rocky composition, which has recently been confirmed by upper limits on its mass. Instead, it's somewhere on the "ocean world" to "mini-Neptune" continuum.
This version of Kepler-22 b was originally included in my old "Exoplanet Updates" addon in 2019, and a modified version of it was released by fyr02 in 2020 here ("Vaporian"). I've just re-released it with updated data.
There's already a good addon for Kepler-62 by MrSpace43 here, with textures based on the NASA artistic impressions. My addon only includes textures for Kepler-62 f. The default texture is the "official" NASA one, from the same (now gone?) source as MrSpace43's Kepler-22 b and my Kepler-186 f, and the alternate surface shows the planet covered by an ocean.
Might as well attach my Kepler-452 b addon here as well, since it didn't have a dedicated post, having been part of "Exoplanet Updates" and then just submitted to celestia.mobi. This is another habitable zone planet, though again fairly large and technically a planet candidate. It's just using the NASA texture, unmodified.
- kepler22.zip
- (320.15 KiB) Downloaded 404 times
- kepler62f.zip
- (3.7 MiB) Downloaded 426 times
- kepler452.zip
- (1.24 MiB) Downloaded 421 times
- Kepler-62 f as an ocean-covered rocky planet
