…and how we know it today

How Did the Earth Form?  KMR0nx8&feature=related KMR0nx8&feature=related  Heat from collisions demo  What is evidence of these collisions?

What is the evidence this happened?  Composition of the earth  Residual heat  Layers (inner, outer, mantle, crust)

Earth began to cool…  But not for long…  Origin of the Moon Origin of the Moon

Evidence of Impact  Earth spins as a result of the impact  Composition of the moon is similar to earth’s crust: (density of moon)  similar oxygen isotope ratios between the Moon and the Earth  Tilt of the earth’s spin

Alternate Theories  The moon formed near the Earth as a separate body  The moon formed as part of the Earth and separated from it  The moon formed somewhere else and was captured by the Earth

Earth Began to Cool  After large impact and moon formation, earth began to cool

How do we know earth rotates? (before we could go to space…)  Foucault Pendulum Foucault Pendulum  Earth bulges at equator  Sunrise/Sunset  Movement activity

How do we know earth revolves?  Parallax  Parallax Diagram Parallax Diagram  Parallax lab 