Kepler-452b is the first near-Earth-size world to be found in the habitable zone of star that is similar to our sun. Until its discovery in 2015, the Kepler telescope had only detected 12 Earth-size planets (smaller than twice the size of Earth) in the habitable zone of their smaller and cooler stars. Kepler-452b is the first planet orbiting a star about the same size and temperature as the sun.

When looking for planets that might support life, scientists start with the habitable zone. The habitable zone is a region around a star where temperatures are right for water—an essential ingredient for life as we know it—to pool on the surface. Scientists don’t know if Kepler-452b can support life. What is known about the planet is that it is about 60 percent larger than Earth, placing it in a class of planets dubbed "super-Earths," with an orbit of 385 days. Scientists believe that Kepler-452b is about 6 billion years old, much older than Earth.