Goldilocks worlds: just right for life?

Of the 1,780 confirmed planets beyond our solar system, as many as 16 are located in their star’s habitable zone, where conditions are neither too hot nor too cold to support life. Size also matters: A planet that’s too small can’t maintain an atmosphere; one that’s too large will have a crushing atmosphere. A recently detected planet 493 light-years from Earth, Kepler-186f, is close to Earth's size and is located in its solar system's habitable zone.

Graphic by John Tomanio and Xaquín G.V., NGM staff.

Source: Abel Méndez, Planetary Habitability Laboratory, University of Puerto Rico at Arecibo

Note: Exoplanet mass estimated from mass-radius relationship when not available.

Star Hot orbital zone Warm Cold