Earth

The Earth from Space

Earth’s Dimensions Radius – 3,827 miles Mass – 6,000,000,000,000,000,000,000,000 kg Distance from the sun -93,000,000 miles Age – 4.8 billion years (4,800,000,000)

Structure of the Earth Biosphere – All parts of the Earth that work together to sustain life Interior Structure of the Earth Surface of the Earth Lithosphere Continents and the ocean floor Hydrosphere Water Atmosphere

Earth’s Interior 3 Layers Crust Mantle Core Floats on top of the mantle Mantle Composed of rock Core Inner – solid iron Outer – molten rock

Earth’s Structure Lithosphere The crust and the uppermost mantle Hard, rigid and brittle

Hydrosphere All water on the surface of the Earth 71% of Earth’s surface is water 98% of all water is in the ocean 1% of water is in polar ice-caps > 1% in rivers, streams, lakes and groundwater

Atmosphere Less than .01% of the mass of Earth Structure Troposphere Most dense layer Responsible for weather Stratosphere Highest level used by humans Planes fly here….why?? Mesosphere and Thermosphere The two outermost layers of the atmosphere

Atmosphere Composition 78 % Nitrogen 21% Oxygen > 1% H2O and CO2 This was not the original composition of Earth’s atmosphere. What do you think the atmosphere was like 4 billion years ago? What changed?

Biosphere Where life exists on Earth Some statistics on life Includes all litho, hydro and atmosphere Some statistics on life 1.5 Million Species cataloged (estimate of 3 million still not known to science) 50% of all known species are insects About 4,000 species of mammals More small organisms than large