Day and night

• Axis


  Imaginary line running through the Earth from the North Pole to the South Pole
• Earth's rotation


  1. Rotates around the axis from west to east

  2. Time taken for one full rotation is a day

  3. Earth takes 24 hours to complete one full rotation
• If it was midnight in Australia right now, the time taken for Earth to complete one full rotation and come back to midnight again is 24 hours
• Earth


  • Half of Earth is bathed in sunlight at any time
  • The other half is in the dark
• As the Earth rotates


  Some countries move into the light while others move out of it
• When it is midday in Brisbane, it's midnight in Rio de Janeiro, Brazil
• When the Sun is setting in Brisbane, the Sun is rising in Rio de Janeiro
• When the Sun is rising in Brisbane, the Sun is setting in Rio de Janeiro
• Earth's axis

  Tilted on an angle of 23.5° from vertical
• As the Earth rotates on its axis

  Some parts of the Earth get more sunlight than others
• Australia is in the Southern Hemisphere
• When the South Pole is tilted away from the Sun


  Australia experiences winter
• When the South Pole is tilted towards the Sun


  Australia experiences summer
• Solstice


  When the ends of the Earth's axis are at their closest or furthest point from the Sun
• There are two solstices per year: the winter solstice and the summer solstice
• Summer solstice


  • South Pole is pointed most closely to the Sun due to the Earth's axis of rotation
  • Occurs on 21 or 22 December every year
  • Longest day of the year in Australia with more than 15 hours of daylight
• Winter solstice


  • South Pole is pointed furthest from the Sun due to the Earth's axis of rotation
  • Occurs on 21 or 22 June every year
  • Shortest day of the year in Australia with just over 9 hours of daylight
• Equinox


  • When the Earth's axis is tilted neither towards or away from the Sun
  • Whole planet experiences approximately 12 hours of daylight and 12 hours of darkness