20 planets similar to Earth cataloged by astronomers

This figure from the Planetary Habitability Laboratory shows a generous habitable zone for stars of different temperatures, as well as the location of terrestrial size planetary candidates and confirmed Kepler planets described in new research. Some of the solar system terrestrial planets are also shown for comparison. Credit: Chester Harman

NASA’s Kepler mission provided astronomers with the data they needed to catalog planets similar to Earth. The 20 candidate planets are less than twice the size of Earth and orbit their star in the conservative habitable zone where liquid water could pool on the surface of the planet.

Of the 20 candidates, nine of them have been determined to be verified planets. They include:

Kepler-62f
Kepler-186f
Kepler-283c
Kepler-296f
Kepler-442b

The paper “A Catalog of Kepler Habitable Zone Exoplanet Candidates” lists the candidates and their properties. 

An imaginative illustration of Kepler-186f, one of the planets found by the Kepler mission believed to be in the habitable zone. Credit: Danielle Futselaar