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Sphere within a Sphere

Size of the Earth

¨Diameter is 12,740 km

¨The largest of the inner planets (Mercury, Venus, Earth and Mars)

Features of the Earth

¨Earth means planet Earth when it is capitalized

¨earth means the soil or ground when it is not capitalized

¨It is a sphere made up of many smaller spheres in and around it

¨70% of Earth’s surface is covered by water

¨The three main features are land, water and air



¨The land areas of Earth known as the crust and the upper mantle

¨Litho – means rock in Greek

¨Lithosphere – means rock sphere

¨Refers to the solid portion of the Earth


¨All the water on Earth

¨Hydro – means water in Greek

¨Hydrosphere – means water sphere

¨It includes all the water on Earth – Oceans, Seas, Rivers, Lakes, Streams, glaciers, precipitation etc.

¨97% of Earth’s water is salt water

¨The most common salt is Sodium Chloride (NaCl2) – table salt

¨The remaining 3% is freshwater – although only 15% is liquid water

¨All life needs water to exist


¨Atmos – means gas or vapor in Greek

¨Atmosphere – the envelope of gases surrounding Earth

¨Contains material necessary to support life