Kepler-438b is an extrasolar planet that circles Kepler-438 a red dwarf star 470 light years away in the constellation Lyra. It is one of the most Earth-like planets with an Earth Simularity Index score of 0.88. The planet was discovered by NASA's Kepler spacecraft using the transit method, as the planet circles it star, it will cross in front of the star causing the star to be less bright as seen from Earth, which can be measured.
- Clavin, Whitney; Chou, Felicia; Johnson, Michele (6 January 2015). "NASA's Kepler Marks 1,000th Exoplanet Discovery, Uncovers More Small Worlds in Habitable Zones". NASA. Retrieved 6 January 2015.
- Sample, Ian (7 January 2015). "Kepler 438b: Most Earth-like planet ever discovered could be home for alien life". The Guardian. Retrieved 7 January 2015.