Stars, wanderers and the cycles of life

1
Stars, wanderers and the cycles of life

• The patterns of stars in the sky do not change
  from one generation to the next
• Ancient cultures developed stories from the
  patterns they saw
• They gave names to patterns - like Orion and The
  Seven Sisters

2
Stars, wanderers and the cycles of life

• There are just 7 objects that are visible to the
  naked eye and that move amongst the patterns of
  the stars
• One of them is the Sun
• The Sun is so bright to us that other stars
  become invisible in daylight - but they are still
  there

3
Stars, wanderers and the cycles of life

• The Sun seems to move against a background of
  fixed stars
• The sequence of patterns behind the Sun is called
  the Zodiac
• The time taken for the Sun to move around the
  Zodiac is the same as the time taken for a cycle
  of the Earths seasons
• You count your age according to these cycles

4
Stars, wanderers and the cycles of life

• The Moon is another of the 7 wanderers
• Its visible sunlit part changes shape, as seen
  from where we are, between a bright full circle
  and a crescent
• Our idea of a month comes from the reliable
  regularity of these cycles of apparent change of
  shape

5
Stars, wanderers and the cycles of life

• As well as yearly cycles of the Sun and cycles of
  the phases of the Moon, there are cycles of light
  and dark that give us day and night
• Our lives are shaped by these cycles

6
Stars, wanderers and the cycles of life

• There are five other wanderers visible to the
  naked eye - Mercury, Venus, Mars, Jupiter and
  Saturn
• There are the same number of visible wanderers as
  days of the week
• In English, three days are named after these
  wanderers - Sunday, Monday and Saturday
• In some languages, all 7 days match the 7 objects
  that wander amongst the fixed stars

7
Stars, wanderers and the cycles of life

• People have never gone far from the Earth - seen
  here from the Moon
• If we inhabited another planet or moon, the
  cycles of our lives would need to be very
  different

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Stars, wanderers and the cycles of lifeimage
credits

• Slide 1 - NASA and H Richer (University of
  British Columbia)
• Slide 2 - NASA JPL
• Slide 3 - Tau olunga
• Slide 4 - Fekete Csaba
• Slide 5 - David Brodie
• Slide 6 - NASA JPL Space Science Institute
• Slide 7 - NASA