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Earth, Moon, and the Sun

The night sky changes through the year

The stars you see after sunset change from March to September.

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The idea

Earth goes round the Sun. The path it takes is its orbit. Going round the Sun is revolution.

The Sun, and Earth's orbit round it.
Step 1 of 6
  1. The Sun, and Earth's orbit round it.
  2. In March, the night side of Earth faces stars A.
  3. In June, it faces stars B.
  4. In September, it faces stars C.
  5. In December, it faces stars D.
  6. After one year, Earth is back. It sees stars A again.

A star rises about 4 minutes earlier each night. After one year it is back at about its first time.

Each night Earth is a little further along its orbit. So the night side faces slightly different stars.

Watch out!

Earth turning makes stars move across one night. Earth going round the Sun makes them change over the year.

Jump to lesson

This track

  1. 0 Start here
  2. 1 Earth is doing two things at once
  3. 2 The Moon keeps one face turned to us
  4. 3 When three line up, one shades another
  5. 4 The Moon shades a patch of Earth
  6. 5 Earth shades the Moon
  7. 6 Why it is not every month
  8. 7 One is safe to watch, the other never is
  9. 8 Checkpoint: motions, the Moon and eclipses
  10. 9 Why the Sun seems to move
  11. 10 Day here, night there
  12. 11 The star that stays still
  13. 12 Checkpoint: the turning sky
  14. 13 The night sky changes through the year
  15. 14 The tilt makes the seasons
  16. 15 The longest and shortest days
  17. 16 Checkpoint: the year, the tilt and the seasons
  18. 17 The big picture
  19. 18 Track quiz

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