The ecosphere is a narrow band around the Sun where the temperature is neither too hot nor too cold for life to exist. Earth is the only planet in this zone, and is therefore the only planet in the Solar System able to support life. Mercury and Venus are too close to the Sun for water to exist in liquid form. The remaining planets lie well beyond the ecosphere, where it is too cold for life. The temperature on Pluto can reach as low as —223 °C (-370°F)!
An ecosphere is a planetary closed ecological system. In this global ecosystem, the various forms of energy and matter that constitute a given planet interact on a continual basis. The forces of the four Fundamental interactions cause the various forms of matter to settle into identifiable layers. These layers are referred to as component spheres with the type and extent of each component sphere varying significantly from one particular ecosphere to another. Component spheres that represent a significant portion of an ecosphere are referred to as a primary component spheres. For instance, Earth’s ecosphere consists of five primary component spheres which are the Geosphere, Hydrosphere, Biosphere, Atmosphere, and Magnetosphere.