Earth, sun & moon: cycles, eclipses, seasons & tides

Earth's rotation on its axis (a full spin every 24 hours) causes day and night. Earth's orbit around the sun (taking about 365 days) combined with Earth's tilted axis causes the seasons — when a hemisphere is tilted toward the sun, it experiences summer; tilted away, it experiences winter. The moon orbits Earth roughly every 27-29 days, and its changing position relative to Earth and the sun causes its phases (new moon, crescent, full moon, etc.). An eclipse happens when the Earth, sun and moon line up: a solar eclipse occurs when the moon blocks the sun's light from reaching Earth, and a lunar eclipse occurs when Earth blocks sunlight from reaching the moon. The moon's gravity (with a smaller pull from the sun) causes ocean tides on Earth.

Key terms

Rotation:

Earth spinning on its axis, causing day and night, once every 24 hours.

Orbit:

The path Earth (or the moon) takes as it circles around another body, like the sun.

Eclipse:

When the Earth, sun and moon line up so one blocks light to another.

Questions

1. 1. Earth's rotation causes:

   • The seasons
   • Day and night
   • Tides
   • Eclipses

2. 2. Earth completes one full rotation approximately every:

   • 1 hour
   • 24 hours
   • 1 week
   • 1 year

3. 3. Earth's orbit around the sun takes approximately:

   • 1 day
   • 1 month
   • 365 days
   • 10 years

4. 4. The seasons are mainly caused by:

   • Earth's distance from the sun changing a lot
   • Earth's tilted axis as it orbits the sun
   • The moon's phases
   • Ocean currents

5. 5. The moon orbits Earth approximately every:

   • 1 day
   • 27-29 days
   • 1 year
   • 10 years

6. 6. A solar eclipse happens when:

   • The moon blocks the sun's light from Earth
   • Earth blocks light from the moon
   • The sun disappears
   • Earth stops rotating

7. 7. Ocean tides are mainly caused by:

   • The sun's heat
   • The moon's gravity
   • Earthquakes
   • Wind alone

8. 8. A lunar eclipse happens when:

   • The moon blocks the sun
   • Earth blocks sunlight from reaching the moon
   • The moon disappears forever
   • The sun blocks Earth

9. 9. When the Southern Hemisphere is tilted toward the sun, Australia experiences:

   • Winter
   • Summer
   • No change
   • Constant night

10. 10. When the Southern Hemisphere is tilted away from the sun, it experiences:

    • Summer
    • Winter
    • Constant day
    • No effect

11. 11. The moon's phases (new moon, full moon, etc.) are caused by:

    • The moon changing shape
    • The changing angle we see the sunlit part of the moon from
    • The moon disappearing and reappearing
    • Clouds on Earth

12. 12. For an eclipse to occur, the Earth, sun and moon must:

    • Be on opposite sides of the galaxy
    • Line up in a particular way
    • Never interact
    • Be the same distance apart always

13. 13. Which causes day and night?

    • Earth's orbit around the sun
    • Earth's rotation on its axis
    • The moon's orbit
    • Ocean tides

14. 14. Which causes the seasons?

    • Earth's rotation
    • Earth's tilted axis combined with its orbit
    • The moon's phases
    • Ocean currents alone

15. 15. Why does Australia's summer occur in December while the UK's summer occurs in June?

    • Earth is closer to the sun in December
    • The two hemispheres are tilted toward the sun at different times of year
    • The UK and Australia have different suns
    • It's simply a calendar coincidence with no real cause

16. 16. Why doesn't a solar eclipse happen every single month, even though the moon orbits Earth monthly?

    • The moon's orbit is tilted slightly relative to Earth's orbit around the sun, so alignment is rare
    • Eclipses only happen once a decade
    • The moon stops orbiting sometimes
    • Solar eclipses happen every month but are invisible

17. 17. High and low tides typically occur roughly twice a day because:

    • Earth rotates through the moon's gravitational pull as the moon's position stays relatively fixed over a day
    • The sun changes position every few hours
    • The moon orbits Earth twice daily
    • Tides are entirely random

18. 18. Which best explains why Earth's distance from the sun is NOT the main cause of the seasons?

    • Earth's orbit is nearly circular, and the hemispheres experience opposite seasons at the same distance from the sun
    • Distance is actually the only cause of seasons
    • Earth's distance from the sun changes dramatically each day
    • The sun's temperature changes with the seasons

19. 19. During a full moon, the arrangement of Earth, sun and moon is roughly:

    • Moon directly between Earth and sun
    • Earth directly between the sun and moon
    • All three in a random unrelated position
    • The moon behind the sun entirely

20. 20. Understanding Earth-sun-moon cycles mainly helps explain:

    • Random, unpredictable events
    • Predictable, recurring phenomena like seasons, tides and eclipses
    • Only unrelated weather
    • Nothing scientifically useful