🪐 Astronomers identify 45 nearby exoplanets as potentially habitable

The search for life beyond our planet is accelerating: a team of astronomers has isolated about forty worlds in our neighborhood with particularly favorable conditions.

Led by Lisa Kaltenegger of the Carl Sagan Institute, this work lists 45 rocky exoplanets that could harbor life. In their approach, the astronomers seek to determine the limits of habitability by including planets with extreme environments, which would normally have been ruled out.


The researchers used data from the European Space Agency's Gaia mission and NASA's exoplanet archives. This information allows for a more accurate calculation of the energy received by each planet, an essential parameter for determining whether liquid water can exist on its surface.

This catalog highlights several notable targets. The TRAPPIST-1 system, located about 40 light-years away, hosts several Earth-sized planets. LHS 1140 b, on the other hand, is considered a super-Earth and could be an ocean world. Closer to us, Proxima Centauri b, orbiting the closest star, continues to attract attention despite a turbulent stellar environment.

Some of these planets have very elliptical orbits, raising questions about their long-term climatic stability. One of the goals of this study is to understand the influence of these trajectories on the possibility of maintaining liquid water.

This catalog serves primarily as a guide for next-generation observation instruments. It indicates which planets are best suited for study by the James Webb Space Telescope or other observatories, in the hope of identifying interesting chemical signatures there.


With the upcoming arrival of more powerful tools, the detailed examination of these 45 worlds could bring us closer to an answer to one of humanity's greatest questions. This study, published in Monthly Notices of the Royal Astronomical Society, marks the beginning of a new concrete step in the search for life in our cosmic neighborhood.

The habitable zone of a star

This region, sometimes called the "Goldilocks zone," is the space around a star where temperatures theoretically allow water to remain liquid on a planet's surface. Its position and extent depend closely on the size and luminosity of the central star. Around a small red dwarf, for example, it is much closer than for a star like our Sun.

Habitability is not solely linked to this condition. The presence of a stable atmosphere, a protective magnetic field, and a suitable geological composition are all important factors. In our Solar System, Venus and Mars are at the edges of the Sun's habitable zone, but neither currently meets all the conditions necessary for Earth-like life.

The definition of this zone evolves with our knowledge. Researchers are now examining models that include different atmospheres or internal heat sources, which could broaden the concept to worlds previously considered too cold, such as some moons of the giant planets.