As far as we know, Earth is the only liveable planet. The atmosphere provides a shield to the void of space and which locks in nitrogen and oxygen for us to breathe.
70% of Earths surface is ocean, which is also inhabited by diverse life forms. Earth is made up of different layers. It has an inner core, an outer core, a mantle and a crust.
Earth also has four types of spheres. They are the hydrosphere, biosphere, lithosphere and atmosphere.
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