Solar System and Universe

A History of the Universe, Solar System, and Planets

Origin of the Universe Evidence (13.8 billion years ago)

• Big Bang Theory

• Background Radiation

Origin of the Solar System

• Solar Nebula Theory (4.6 billion years go)

• therefore Earth is 4.6 billion years old, used to be uniform composition (silicate, etc)

Earth

• differentiated into layers because of internal heat from meteorite impact, radioactive decay

Overview of Earth's composition at different depths:

• Crust - ranges from 5 to 90 km thick (continental vs. oceanic)

• Mantle - approximately 2,900 km thick.

• Outer Core - about 5,150 km in depth.

• Inner Core - total depth reaches around 6,380 km.