GJ 667 Ce is another rocky planet in the same remarkable triple-star system as planet “c,” located 23.6 light-years away. It is the fourth planet from its star, Gliese 667 C.
Key Physical Characteristics
- Planet Type: Terrestrial (rocky) Super-Earth.
- Mass: It is estimated to be about 2.7 times the mass of Earth.
- Orbit: It orbits its red dwarf star every 62 Earth days.
- The Star: It orbits the same red dwarf (Component C) as planet “c,” which is part of a larger three-star system.
Habitability & Environment
In Lisa Kaltenegger’s catalog, GJ 667 Ce is considered a “colder” candidate for life compared to its inner sibling:
- Location: It sits on the outer edge of the habitable zone.
- Energy Intake: It receives only about one-third (33%) of the starlight that Earth gets from the Sun. This puts it in a position similar to Mars or even further out.
- Temperature: Without a very thick atmosphere, this planet would likely be a frozen world. However, if it has a strong greenhouse effect (high levels of CO2), it could potentially maintain liquid water under its clouds.
- Tidal Locking: Like its siblings, it is likely tidally locked, though its greater distance from the star might allow for more complex atmospheric circulation.
Scientific Significance
- The “Habitable Trio”: The Gliese 667 C system is extraordinary because it originally appeared to have up to three planets (c, e, and f) all within the habitable zone at once. This makes it a perfect laboratory for studying how life might differ at the inner, middle, and outer edges of a “Goldilocks” zone.
- Atmospheric Testing: Because it is further out, it is less likely to have its atmosphere stripped away by stellar flares, making it a “safer” long-term environment than planets very close to their stars.
