ABSTRACT
This chapter examines the Earth's place in the Universe, and particularly in the solar system. This will give a sense of the scale of distances and will place the Earth in its spatial environment. Ancient civilizations originally believed the Earth was flat, as shown by Hecataeus's circular map. The only planets that have dense atmospheres are the Earth and Venus. The Earth's atmosphere is predominantly nitrogen and oxygen. Venus's atmosphere is essentially carbon dioxide with a total pressure 96 times higher than that of Earth. Like the Earth, the telluric planets are made up of a series of concentric layers with various physical states (solid, liquid), chemical composition, and relative thickness. The Earth is a planet that is similar to other telluric planets in regards to: volcanic phenomena; and tectonic phenomena. Meteorites come from the debris of planets, asteroids or comets.
