10 Exoplanets That Could Host Alien Life

Kepler-186f is the first truly Earth-size exoplanet ever found in its host star's habitable zone. The alien world, which lies 490 light-years from Earth.

This planet is a controversial find. It was discovered in 2010, but there has been difficulty in getting it confirmed.

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Another "super-Earth", Gliese 667Cc is also close by Earth: about 22 light-years away in the constellation Scorpius. The planet is at least 4.5 times bigger than Earth.

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While Kepler-22b is bigger than Earth, it circles a star that is quite close in size and temperature to Earth's sun. Kepler-22b is 2.4 times Earth's size.

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"Super-Earth" HD 40307g orbits comfortably inside the habitable zone of its parent star. It lies about 42 light-years away from Earth in the constellation Pictor.

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HD 85512b was announced in 2011 as part of a treasure trove of 50 planets discovered by the High Accuracy Radial velocity Planet Searcher instrument, or HARPS, in Chile.

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The planet candidate Tau Ceti e, which was detected in December 2012, is found just 11.9 light-years from Earth.

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The mass of Gliese 163c puts the planet in a gray zone. The planet is seven times the mass of Earth, which could make it a very large rocky planet or a dwarf gas giant.

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At least one study supposes that Gliese 581d might have a thick, carbon dioxide atmosphere. It is about seven times more massive than Earth.

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Tau Ceti f is a super-Earth candidate like its sibling Tau Ceti e, but it orbits close to the outer edge of Tau Ceti's habitable zone.

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Kepler-186f is the first truly Earth-size exoplanet ever found in its host star's habitable zone. The alien world, which lies 490 light-years from Earth.

Kepler-186f

This planet is a controversial find. It was discovered in 2010, but there has been difficulty in getting it confirmed.

Gliese 581g

Another "super-Earth", Gliese 667Cc is also close by Earth: about 22 light-years away in the constellation Scorpius. The planet is at least 4.5 times bigger than Earth.

Gliese 667Cc

While Kepler-22b is bigger than Earth, it circles a star that is quite close in size and temperature to Earth's sun. Kepler-22b is 2.4 times Earth's size.

Kepler-22b

"Super-Earth" HD 40307g orbits comfortably inside the habitable zone of its parent star. It lies about 42 light-years away from Earth in the constellation Pictor.

HD 40307g

HD 85512b was announced in 2011 as part of a treasure trove of 50 planets discovered by the High Accuracy Radial velocity Planet Searcher instrument, or HARPS, in Chile.

HD 85512b

The planet candidate Tau Ceti e, which was detected in December 2012, is found just 11.9 light-years from Earth.

Tau Ceti e

The mass of Gliese 163c puts the planet in a gray zone. The planet is seven times the mass of Earth, which could make it a very large rocky planet or a dwarf gas giant.

Gliese 163c

At least one study supposes that Gliese 581d might have a thick, carbon dioxide atmosphere. It is about seven times more massive than Earth.

Gliese 581d

Tau Ceti f is a super-Earth candidate like its sibling Tau Ceti e, but it orbits close to the outer edge of Tau Ceti's habitable zone.

Tau Ceti f