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Gliese 667 Cc - Super Earth exoplanet 22 light years from Earth

Posted on:June 1, 2023

Artist’s conception of Gliese 667 Cc

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Gliese 667 Cc also known as GJ 667Cc, HR 6426Cc, or HD 156384Cc is an exoplanet orbiting within the habitable zone of the red dwarf star Gliese 667 C.


Planet typeSuper Earth
Discovery date21 November 2011
Discovered byEuropean Southern Observatory
Mass3.8 Earths
Planet radius1.77 x Earth
Orbital radius0.125 AU
Orbital period28.1 days
Detection methodRadial Velocity
StarGliese 667 C


Gliese 667 Cc was first announced in a pre-print made public on 21 November 2011 by the European Southern Observatory’s High Accuracy Radial Velocity Planet Searcher (HARPS) group using the radial velocity method also known as Doppler method.

Host star

The planet orbits a red dwarf (M-type) star named Gliese 667 C, orbited by a total of two planets. Gliese 667 C has a mass of 0.31 M and a radius of 0.42 R. It has a temperature of 3,700 K


Although Gliese 667 Cc is located in a habitable zone, the conditions on the planet could be very different from our Earth. Life would be facing some potential challenges, which may include low and varying light conditions, possibly a higher atmospheric pressure, and violent flares.

The planet is likely tidally locked, with one side of its hemisphere permanently facing towards the star, and the opposite side being dark and cold. We can only speculate how fauna and flora, if present at all, would evolve under such different conditions.

If the composition of its atmosphere is similar to Earth it may well have surface temperatures of around 30C (86F). This would allow for the presence of liquid water which makes Gliese 667Cc an exciting prospect in terms of habitability.


Artist’s conception of Gliese 667 Cc


A similar atmospheric composition to Earth would produce temperatures slightly higher than on Earth, a thicker atmosphere may produce a runaway greenhouse effect. With a similar atmosphere and composition to Earth it is possible life could exist on Gliese 667 Cc.

It’s important that Gliese 667 Cc is considered a potentially habitable exoplanet, its habitability and the presence of water or life are still speculative.