fr en es pt
Astronomy
Asteroids and Comets Black Holes Children Chemical Elements Constellations Earth Eclipses Environment Equations Evolution Exoplanets Galaxies Light Matter Moons Nebulas Planets and Dwarf Planets Probes and Telescopes Scientists Stars Sun Universe Volcanoes Zodiac New Articles Shorts Archives Glossary
RSS astronoo
Follow me on X
Follow me on Bluesky
Follow me on Pinterest
English
Français
Español
Português
 


Last updated July 28, 2025

The New Promised Lands: Top Candidates for Habitability

Comparison with the habitable planets of the Kepler 11 system

What is a habitable planet?

The concept of a habitable planet refers to a celestial body whose physical and chemical conditions allow the emergence, development, and persistence of life as we know it. These conditions mainly include the presence of liquid water, a moderate temperature, a protective atmosphere, and energy sources. In astrophysics, this zone is often called the "habitable zone" (or Goldilocks zone) around a star, that is, the region where a planet can theoretically maintain liquid water on its surface for billions of years.

Physical and chemical criteria for habitability

For a planet to be potentially habitable, several criteria must be met:

Examples of potentially habitable planets

The Kepler, TESS, and now James-Webb missions have identified several rocky exoplanets in the habitable zone of their star. Some of them, such as Proxima b, TRAPPIST-1e, Kepler-442b, or LHS 1140b, are considered serious candidates. However, these observations do not yet allow the direct detection of biosignatures.

Comparison of the main candidates

Comparison of some potentially habitable exoplanets
ExoplanetMass (Earth = 1)Radius (Earth = 1)Distance (LY)Habitable zoneType of star
Proxima Centauri b1.27~1.14.24YesRed dwarf M5.5
TRAPPIST-1e0.770.9239.6YesUltra-cool dwarf
Kepler-442b2.361.341,206YesOrange dwarf K
LHS 1140b6.61.741YesRed dwarf M4.5
Kepler-22b~8.7 (estimate)2.4620YesYellow dwarf G5
Kepler-62f~2.8 (estimate)1.41,200YesK2 dwarf
Kepler-186f~1.4 (estimate)1.1490YesM1 dwarf
Kepler-11f~2.32.62,000 (approx.)Inner limitYellow dwarf G
Kepler-11g~8.03.32,000 (approx.)Outer limitYellow dwarf G

Life elsewhere: a probability or an exception?

Even if the physical conditions of some exoplanets seem promising, the chemical complexity leading to life remains an open question. The emergence of life depends on many stochastic processes (effect of chance): prebiotic chemistry, self-organization, homochirality, encapsulation, and stability over time. In this context, life could be frequent in the Universe, but complex life probably remains unfindable.

Exo-Earths: These Distant Worlds that Resemble Earth

Habitable planets constitute one of the most dynamic fields of modern astrophysics. They pave the way for a new era of space exploration, focused not only on celestial objects but on the search for another form of life. The development of observatories like JWST or ELT could, in the near future, allow the detection of spectroscopic biosignatures.

References:
• Kaltenegger L., How to Characterize Habitable Worlds and Signs of Life, Annual Review of Astronomy and Astrophysics, 2017.
• NASA Exoplanet Archive: https://exoplanetarchive.ipac.caltech.edu/
• Seager S., Exoplanet Habitability, Science, vol. 340, 2013.

Articles on the same theme

Gliese 581 g: A Serious Candidate for Habitability Gliese 581 g: A Serious Candidate for Habitability
Discovery of solid buckyballs Discovery of solid buckyballs
Kepler-22b: First Habitable Exoplanet Discovered in the Temperate Zone Kepler-22b: First Habitable Exoplanet Discovered in the Temperate Zone
Exoplanets: Techniques and Discoveries Exoplanets: Techniques and Discoveries
Cheops, characteristics of exoplanets Cheops, characteristics of exoplanets
Mini-Neptunes: A Fascinating Class of Extrasolar Planets Mini-Neptunes: A Fascinating Class of Extrasolar Planets
Turn Off the Stars to Detect Life! Turn Off the Stars to Detect Life!
The New Promised Lands: Top Candidates for Habitability The New Promised Lands: Top Candidates for Habitability
JWST, the end of the dark ages JWST, the end of the dark ages
The Milky Way: A Galaxy Teeming with Habitable Worlds The Milky Way: A Galaxy Teeming with Habitable Worlds
HD 100546 b: A Giant Exoplanet Forming in an Extended Habitable Zone HD 100546 b: A Giant Exoplanet Forming in an Extended Habitable Zone
Super-Earths: Habitable Planets in Sight? Super-Earths: Habitable Planets in Sight?
The habitable zone of the Kepler-186 system The habitable zone of the Kepler-186 system
Exoplanètes Errantes : Mondes Perdus dans l’Obscurité Cosmique Exoplanètes Errantes : Mondes Perdus dans l’Obscurité Cosmique
Kepler space telescope in search of life Kepler space telescope in search of life
55 Cancri e, the diamond planet 55 Cancri e, the diamond planet
Number of candidate and confirmed exoplanets Number of candidate and confirmed exoplanets
Trappist or the harmony of the cosmos Trappist or the harmony of the cosmos

1997 © Astronoo.com − Astronomy, Astrophysics, Evolution and Ecology.
"The data available on this site may be used provided that the source is duly acknowledged."
How Google uses data
Legal mentions
English Sitemap − Full Sitemap
Contact the author