Exoplanet Gliese 12 b, 40 light-years away, may have Earth-like conditions and atmosphere.
Key Takeaways
- Gliese 12 b, dubbed an ‘exo-Venus,’ is a temperate, Earth-size planet 40 light-years away.
- Its estimated surface temperature of 42°C makes it cooler than most known exoplanets.
- The planet’s potential habitability depends on the presence and type of atmosphere it possesses.
- Scientists aim to study Gliese 12 b to bridge the gap between Earth’s and Venus’s evolution.
- The calm nature of its red dwarf host star raises hopes for an intact, stable atmosphere.
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Gliese 12 b: A Potentially Habitable ‘Exo-Venus’
Astronomers have identified a promising Earth-like exoplanet, Gliese 12 b, located 40 light-years away in the constellation Pisces. This discovery, detailed in the study “Gliese 12 b: A Temperate Earth-Sized Planet at 12 Parsecs Discovered with TESS and CHEOPS,” published in the Monthly Notices of the Royal Astronomical Society, offers exciting potential for studying the conditions required for habitability in planets beyond our solar system.
Slightly smaller than Earth but similar in size to Venus, Gliese 12 b orbits its red dwarf star every 12.8 days and receives 1.6 times more energy than Earth does from the Sun. With an estimated surface temperature of 42°C (107°F), the planet falls between Earth and Venus in terms of solar radiation and equilibrium temperature. Its habitability, however, depends on whether it has an atmosphere and what type it might be—Earth-like, Venusian, or entirely unique.
Unraveling the Mystery of Atmospheres
Gliese 12 b’s host star, Gliese 12, is smaller and cooler than the Sun, measuring just 27% of its size and with only 60% of its surface temperature. Its calm nature—free from extreme magnetic storms and flares—raises hopes that the planet might retain its atmosphere, a critical factor for habitability. The researchers used NASA’s TESS (Transiting Exoplanet Survey Satellite) and CHEOPS observations to identify the exoplanet, which is among the few temperate, transiting Earth-sized worlds close enough for detailed atmospheric studies.
The transit method of detection, where a planet passes in front of its star, allows astronomers to analyze starlight filtered through the planet’s atmosphere. This method can reveal its chemical composition and suitability for life. Comparisons with Venus and Earth suggest that Gliese 12 b could help scientists understand how planets’ atmospheres evolve and why some, like Venus, become inhospitable, while others, like Earth, remain habitable.
A Key Target for Future Studies
While Gliese 12 b is not the closest Earth-like exoplanet—Proxima Centauri b holds that title—it stands out as the “nearest, transiting, temperate, Earth-size world” known so far. Its proximity makes it an excellent candidate for follow-up studies with telescopes like the James Webb Space Telescope, which can probe its atmosphere.
The discovery also aligns with growing interest in planets orbiting red dwarf stars, which are abundant in the Milky Way. While the TRAPPIST-1 system has yielded similar discoveries, many of its planets lack atmospheres, diminishing their chances of supporting life. Gliese 12 b, however, offers renewed hope for understanding planetary evolution and habitability.
As Dr. Shishir Dholakia, a co-lead researcher, explains, studying Gliese 12 b “will advance our understanding of habitability on planets across our galaxy.”
