Kepler 438b is an Earth-like extrasolar planet orbiting the star Kepler 438, some 470 lightyears away in Lyra. The planet has an ESI (Earth Similarity Index) of 0.88, the highest currently measured. It's an indication of how similar physically a given world is compared to Earth, and it takes into account the planet's mass, radius, density, escape velocity and surface temperature. Although Kepler 438b is similar physically the Earth, the star Kepler 438 is a flaring red dwarf, highly volatile. It is therefore quite unlikely that the planet harbors any form of life, despite its high ESI.