Earth's Motions Summary

Introduction

• Exploration of Earth's movements: rotation and revolution
• Effects on day/night and seasons

Axis

• Imaginary vertical line at the center of Earth's spin
• Tilted at an angle

Rotation

• Definition: Spinning of the Earth on its axis
• Direction: West to East
• Duration: 24 hours
• Effects: Causes day/night
• Facing Sun: Day
• Facing away from Sun: Night
• East sees Sun first due to rotation direction

Revolution

• Definition: Movement of Earth around the Sun
• Speed: 30 km/second
• Duration: 365 days and 6 hours
• Leap Year: Extra day every four years

Key Terms

• Rotation: Spinning on axis
• Revolution: Movement around the Sun
• Axis: Imaginary vertical line
• Orbit: Fixed path of movement around the Sun
• Northern Hemisphere: Top half of Earth
• Southern Hemisphere: Bottom half of Earth

Seasons

• Caused by Earth's revolution and tilted axis

• Hemispheres:

• Equator divides Earth into Northern and Southern Hemispheres

• North Pole: Northernmost point

• South Pole: Southernmost point

• Seasonal Changes:

• Northern Hemisphere (April to June):

  • Tilts towards the Sun
  • Longer days = Summer

• Southern Hemisphere (November to January):

  • Tilts towards the Sun
  • Longer days = Summer
  • Opposite seasons between hemispheres

In a Nutshell

• Two main movements: rotation and revolution
• Rotation: Causes day/night
• Revolution: Causes seasons
• Both movements are influenced by the tilted axis of the Earth.