Earth's Shape and Movement Summary

Earth's Shape and Movement

Earth's Shape

• The Earth's shape is a Geoid.
• It is not a perfect circle and is not flat.

Rotation

• Earth spins on its own axis.
• It takes 24 hours to complete one rotation.
• This allows us to experience day and night.
• The line of illumination separates day and night.
• Polar Night: Utqiagvik, Alaska experiences darkness from November to January.
• Midnight Sun: Utqiagvik experiences the midnight sun between April and August.

Revolution

• Revolution is when the earth completes one full movement.
• The tilt of the Earth and the revolution around the sun cause the seasons.

Solstices

• Winter Solstice (June):
  • Northern Hemisphere is tilted towards the sun.
  • Southern Hemisphere is tilted away from the sun.
  • The sun's rays shine directly over the Tropic of Cancer.
  • Southern Hemisphere has shorter days and longer nights.
  • The South Pole has 24 hours of night.
• Summer Solstice (December):
  • Southern Hemisphere is tilted towards the sun.
  • Northern Hemisphere is tilted away from the sun.