Earth 2.0? Astronomers have discovered the nearest-yet potentially-habitable planet with Earth-like temperatures!

In our ongoing search for alien life, astronomers have scoured the cosmos, longing for a connection beyond our own world. While the dream of encountering intelligent beings remains distant, we might just have chanced upon a planet that mirrors our own with uncanny familiarity.

In a remarkable revelation, astronomers have pinpointed a potentially habitable Earth-like exoplanet merely 40 light-years away, with temperatures only slightly higher than those on our planet.

This intriguing new world, named Gliese 12 b, completes an orbit around its star every 12.8 days. Comparable in size to Venus and only slightly smaller than Earth, it boasts an estimated surface temperature of 42°C, cooler than most of the 5,000-plus confirmed exoplanets (planets outside our solar system).

The key question now is its atmosphere. It might harbour an atmosphere like Earth’s, a nightmarish greenhouse scenario akin to Venus, or perhaps an entirely unique composition not observed within our solar system.

Unravelling its atmospheric mysteries could unveil whether Gliese 12 b is capable of sustaining temperatures suitable for liquid water. This, in turn, would be indicative of its potential to harbour life. This discovery could also offer insights into why Earth and Venus, despite their similarities, have evolved to house such different environments.

NASA has underscored the significance of Gliese 12 b, highlighting it as one of the select few Earth-like exoplanets deserving of closer examination. Described as “the nearest, transiting, temperate, Earth-size world located to date,” it stands as a prime candidate for further exploration by the James Webb Space Telescope.


Gliese 12 b orbits a cool red dwarf star named Gliese 12, located almost 40 light-years away in the constellation Pisces. The star is about 27% the size of our sun and has a surface temperature around 60% of the sun’s.

The implications of this discovery extend beyond the confines of a single exoplanet. It has the potential to reveal whether most Milky Way stars, which are categorised as cool stars, can host temperate planets with atmospheres, which would make them habitable.

Fascinatingly, the proximity between Gliese 12 b and its host star amounts to just 7% of the distance separating Earth and the sun. Consequently, the exoplanet receives 1.6 times more energy than Earth and experiences approximately 85% of Venus's solar radiation.

This proximity also means the planet's surface temperature depends heavily on its atmospheric conditions. While estimates place Gliese 12 b's temperature at 42°C, Earth, in contrast, maintains an average surface temperature of 15°C.

Reflecting on these discoveries, Larissa Palethorpe, co-lead of the research and a doctoral student at the University of Edinburgh and University College London, remarked: “It is thought that Earth's and Venus's first atmospheres were stripped away and then replenished by volcanic outgassing and bombardments from residual material in the solar system.

“The Earth is habitable, but Venus is not due to its complete loss of water. Because Gliese 12 b is between Earth and Venus in temperature, its atmosphere could teach us a lot about the habitability pathways planets take as they develop.”

This paper has been published in the Monthly Notices of the Royal Astronomical Society and can be accessed here.