Kepler-22b is a planet orbiting in the habitable zone of its sun-like star, Kepler-22, which is located roughly 600 light-years from Earth. With a radius of about 2.4 times that of Earth, astronomers noted after its discovery in 2011 that the planet's temperatures about the same. If the greenhouse effect is the same as well, scientists estimated its surface temperature is a life-friendly 72 degrees Fahrenheit (22 degrees Celsius).Although the planet is larger than Earth, astronomers hailed the discovery as a step to Kepler's goal of discovering Earth-size planets in the habitable zones of their respective stars.