NASA’s Kepler mission has discovered more than 150 confirmed planets orbiting distant stars. Planets with a known size and orbit are shown below, including Kepler 78b, which has an Earthlike composition.
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Relative size of planets
Relative size of Mercury’s orbit
Stars and planets are enlarged for visibility.
Relative size of stars
3 times as wide
Kepler 22b was the mission’s first confirmed planet in the habitable zone.
Kepler 47c is in the habitable zone, but as a gas giant it would not be hospitable to life.
The two outer planets of the Kepler 62 system may lie in the habitable zone, where liquid water could exist on the surface.
The Sun and the inner three planets of our solar system are shown here for comparison. At this scale the Earth is barely visible.