ESS Formation of Earth Notes

1. Formation of Earth Notes
History of Earth Unit

2. Accretion:
 4.6 Billion years ago gas and dust began to clump together forming
asteroids, then a planetismal, and then a planet

3. Core Accretion:
 The heavier elements sunk to the
center due to their density; heat
generated by collisions/friction

4. Where did most of the water come from?
 At various points Earth is bombarded by asteroids and comets bringing
more water to the planet

5. Formation of the Moon
 A smaller proto-planet, Theia, strikes Earth adding mass to it while ejecting
materials that become the moon; cause of tilt

6. Cooling of Earth
 The Earth begins to cool allowing the atmosphere and oceans to form;
molten crust solidifies to form tectonic plates moved by the mantle

7. Plate Tectonics:
 The movement of the
tectonic plates by
mantle convection
heated by the core of
the Earth; allows for
continental
recombinations