Kepler-438b  Kepler-438b (also known by its Kepler Object of Interest designation "KOI-3284.01") is a confirmed near-Earth-sized exoplanet. It is likely rocky. It orbits on the inner edge of the habitable zone of a red dwarf, Kepler-438, about 640 light-years (196 parsecs) from Earth in the constellation Lyra. It receives 1.4 times our solar flux. The planet was discovered by NASA's "Kepler" spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015. Kepler-438b is an Earth-sized planet, an exoplanet that has a mass and radius close to that of Earth. It has a radius of 1.12 , and an unknown mass. It has an equilibrium temperature of , close to that of Earth. The planet orbits a (M-type) red dwarf star named Kepler-438. The star has a mass of 0.54 and a radius of 0.52 , both lower than those of the Sun by almost half. It has a surface temperature of 3748 K and is estimated to be about 4.4 billion years old, only 200 million years younger than the Sun and the Sun has a surface temperature of 5778 K. The star's apparent magnitude, or how bright it appears from Earth's perspective, is 14.467. Therefore, it is too dim to be seen with the naked eye. Kepler-438b orbits its parent star once every 35.2 days. It is likely tidally locked due to its close distance to its star. A search for exomoons by the Hunt for Exomoons with Kepler project around Kepler-438b placed a maximum mass on a hypothetical moon at 29% that of the planet. The planet was announced as orbiting within the habitable zone of Kepler-438, a region where liquid water could exist on the surface of the planet. However it has been found that this planet is subjected to powerful radiation activity from its parent star every 100 days, much more violent storms than the stellar flares emitted by the Sun and which would be capable of sterilizing life on Earth. Researchers at the University of Warwick say that Kepler-438b is not habitable due to the large amount of radiation it receives. The question of what makes a planet habitable is much more complex than having a planet located at the right distance from its host star so that water can be liquid on its surface: various geophysical and geodynamical aspects, the radiation, and the host stars plasma environment can influence the evolution of planets and life, if it originated.