List of potentially habitable exoplanets

This list shows exoplanets that could possibly be habitable. Most of the entries come from estimates made by the Habitable Worlds Catalog (HWC), along with data from the NASA Exoplanet Archive. The HWC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo.

Scientists think that planetary habitability needs a special kind of orbit. A planet must be at the right distance from its host star so that liquid water can exist on its surface. Other things matter too, such as geophysical and geodynamical features, how thick the atmospheric layer is, and the type and strength of radiation. The host star's plasma environment also plays a part.

Main list

This is a dynamic list, so it may never be fully complete. You can help by editing the page to add missing items, with references to reliable sources.

This list shows confirmed exoplanets in the circumstellar habitable zone. These are planets that are either less than 10 times the mass of Earth or less than 2.5 times Earth's width, so they might be rocky. Being on the list does not mean a planet can support life. Larger planets are less likely to be rocky and more likely to be sub-Neptunes. Earth is included for comparison, and Venus and Mars are included for reference only. Values with a "~" have not been measured and are predicted instead.

Current candidates

See also: List of Kepler exoplanet candidates in the habitable zone and Superhabitable world

This list changes over time and may never be finished. You can help by editing the page to add missing planets, with links to reliable sources.

This is a list of interesting planets outside our Solar System that orbit in the circumstellar habitable zone. These planets are either under 10 Earth masses or smaller than 2.5 Earth radii. They have not been confirmed yet. Earth is included for comparison. Venus and Mars are included only for reference.

Previous candidates

Some planets found using radial velocity were once thought to possibly be habitable. Later studies suggested that these signals may have come from the star itself, not from planets. These include Gliese 581 d and g, Gliese 667 Ce and f, Gliese 682 b and c, Kapteyn b, Gliese 229 Ac, HD 85512 b and Gliese 832 c. Other planets, such as Gliese 180 b, were also once thought to be possibly habitable. Later, they were found to be closer to their star than the habitable zone. Tau Ceti e, HD 85512 b and Kepler-69c were also thought to be likely habitable. However, better models of the habitable zone mean PHL no longer lists them as potentially habitable. Kepler-438b was first thought to be potentially habitable too. Later, it was found to be hit by strong flares, which can strip a planet of its atmosphere. Because of this, it is now considered non-habitable.

K2-3d and K2-18b were first thought to be potentially habitable. K2-18b is still on the HWC list, but recent studies show that both are gas-filled sub-Neptunes rather than the Hycean planet type. This means they are unlikely to be habitable. Kepler-1638b was once thought to be a possibly habitable planet smaller than 2 Earth radii. Later, measurements of the star's distance from Gaia showed that the planet is larger, at 3.226 Earth radii. This makes it more likely to be an ice giant like Neptune, which has a poor chance of being habitable. KOI-1686.01 was also considered potentially habitable after it was detected in 2011. In 2015, NASA showed that it was not a real planet. Kepler-577b and Kepler-1649b were also considered potentially habitable before they were confirmed. New data show that they are no longer considered habitable. TRAPPIST-1 d was considered potentially habitable until JWST/NIRSpec data found little evidence of an atmosphere with Earth-like surface pressure. This made habitability very unlikely.

Extrasolar candidates for liquid water

Scientists have not yet confirmed that liquid water exists anywhere beyond Earth. Most known extrasolar planetary systems seem very different from the Solar System. This may partly be because of sampling bias from the detection methods used. Current searches look for Earth-sized planets in the habitable zone of their systems, which is also called the Goldilocks zone. Some planets with oceans might be Earth-sized moons of giant planets, but scientists are not sure such moons really exist. Evidence suggests that rocky planets with water may be common across the Milky Way galaxy. In June 2020, NASA scientists reported that exoplanets with oceans may be common there. This was based on mathematical modeling studies.

The list below includes possible candidates that meet several rules. Each must be a confirmed object at least as heavy as Earth, and it must orbit in the habitable zone. It must not be a star. It must have been studied for more than a year and have a confirmed surface that is solid or liquid. It must show water vapour in its atmosphere. Models must also predict that it has a wet layer.

Proxima Centauri b is the nearest known exoplanet. It is in the habitable zone of its host star, and it might contain liquid water. More details are needed to judge whether it could be habitable. Gliese 667 Cc circles a dim red star every 28 days. It receives 90% of the light that Earth gets, mostly as infrared light. It is expected to take in about the same energy from its star as Earth takes from the Sun. This could allow temperatures similar to Earth's and perhaps liquid water.

The list also includes Kepler-22b. It also includes Kepler-62e, which is one of two planets in Kepler-62 at a distance that could allow liquid water. Kepler-62f is only 40 percent larger than Earth. LHS 1140 b was first thought to hold a lot of water and may be an ocean world. A later study found it to be lighter than first thought and possibly a dense mini-Neptune. JWST observations rule out a hydrogen-rich atmosphere, which supports the ocean world idea. Finally, the list includes TRAPPIST-1e, TRAPPIST-1f, and TRAPPIST-1g.