Astronomy & Space · Unit 3
The Moon, Earth and Seasons
Moon phases, Earth's spin and orbit, seasons and eclipses
Three of the most commonly misunderstood things in science sit in this unit, and all three have explanations that are simple once the geometry is right.
It covers Earth's spin and the day, its orbit and the year, why the seasons happen, the phases of the Moon, and eclipses - which are rarer than the geometry alone would suggest.
This unit breaks down into 21 short steps and 120 questions, starting at difficulty 1 and building to 2. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.
- Steps
- 21
- Questions
- 120
- Difficulty
- 1-2
What this unit covers
- Eclipses
- Earth Spins
- Why We Have Seasons
- Phases of the Moon
- Earth Orbits the Sun
Where this fits
Follows Our Solar System. Gravity and Orbits explains the mechanics underneath.
Where people slip
Seasons are caused by axial tilt, not by distance from the Sun. Earth is closest to the Sun during the northern winter, which settles the question on its own.
How the unit is structured
The Moon, Earth and Seasons runs as 21 short steps that unlock in order. 15 are practice rounds and 6 are challenge rounds that pull together everything before them. Questions start at difficulty 1 and climb to 2 as you progress.
Challenge rounds
Example questions
30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 120 in the unit altogether.
Earth Orbits the Sun
- Build the sentenceLevel 1
1. Build a true sentence about Earth and the Sun.
Answer: Earth goes around the Sun
Earth travels in a big circle around the Sun.
- Fill the blankLevel 1
2. Earth travels around the Sun along a path called an ____.
- orbitcorrect
- axis
- eclipse
- phase
The path a planet follows around the Sun is its orbit.
- Guess the numberLevel 1
3. About how many days does Earth take to orbit the Sun once?
Answer: 365 days
Earth takes about 365 days for one trip around the Sun.
- Match the pairsLevel 1
4. Match each motion to how long it takes.
Answer: Earth spins once = One day; Earth orbits the Sun once = One year; Moon orbits Earth once = About one month
Spinning makes a day, orbiting the Sun makes a year, and the Moon takes about a month.
- Multiple choiceLevel 1
5. How long does Earth take to travel once around the Sun?
- About one yearcorrect
- About one day
- About one week
- About one month
One full trip around the Sun takes about one year.
- Put in orderLevel 2
6. Put these lengths of time in order, from shortest to longest.
Answer: A day -> A week -> A month -> A year
A day is shorter than a week, a week shorter than a month, and a month shorter than a year.
Earth Spins
- Build the sentenceLevel 1
7. Build a true sentence about how often Earth spins.
Answer: Earth spins once every day
Earth spins once every day, giving us day and night.
- Choose all that applyLevel 1
8. Which of these does Earth's spin cause?
- Day and nightcorrect
- The Sun seeming to rise and setcorrect
- The four seasons
- The Moon's phases
Spinning gives us day and night and makes the Sun seem to rise and set.
- Fact or fibLevel 1
9. The side of Earth facing the Sun has daytime.
Answer: True
The side turned toward the Sun is lit, so it is daytime there.
- Fill the blankLevel 1
10. Earth spins on its ____, which gives us day and night.
- axiscorrect
- orbit
- shadow
- Moon
The axis is the imaginary line Earth turns around as it spins.
- Guess the numberLevel 1
11. How many hours are in one day, which is one full spin of Earth?
Answer: 24 hours
Earth spins once about every 24 hours, so a day is 24 hours long.
- Multiple choiceLevel 1
12. How long does Earth take to spin around one time?
- About 24 hourscorrect
- About one week
- About one year
- About one minute
Earth spins around once about every 24 hours, which is one day.
Eclipses
- Build the sentenceLevel 1
13. Build a true sentence about a solar eclipse.
Answer: The Moon can block the Sun
In a solar eclipse, the Moon can block the Sun's light.
- Fact or fibLevel 1
14. A solar eclipse happens when the Moon moves in front of the Sun.
Answer: True
Yes, the Moon blocks the Sun's light during a solar eclipse.
- Fill the blankLevel 1
15. A ____ eclipse happens when Earth's shadow lands on the Moon.
- lunarcorrect
- solar
- star
- sunny
When Earth's shadow covers the Moon, we call it a lunar eclipse.
- Multiple choiceLevel 1
16. During a solar eclipse, what blocks the Sun?
- The Mooncorrect
- A cloud
- Earth's shadow
- Another star
In a solar eclipse the Moon moves in front of the Sun and blocks its light.
- Choose all that applyLevel 2
17. Which of these are true about eclipses?
- A solar eclipse needs a new mooncorrect
- A lunar eclipse needs a full mooncorrect
- Eclipses happen every single month
- The Sun blocks the Moon in a solar eclipse
A solar eclipse needs a new moon and a lunar eclipse needs a full moon.
- Match the pairsLevel 2
18. Match each eclipse word to what it means.
Answer: Solar eclipse = Moon blocks the Sun; Lunar eclipse = Earth's shadow on the Moon; Blood moon = Reddish Moon in eclipse
Solar means the Moon blocks the Sun; lunar means Earth's shadow hits the Moon.
Phases of the Moon
- Choose all that applyLevel 1
19. Which of these are real Moon phases?
- Full mooncorrect
- Crescent mooncorrect
- Square moon
- Triangle moon
Full moon and crescent moon are real phases; square and triangle moons are not.
- Fact or fibLevel 1
20. A new moon is very hard to see in the sky.
Answer: True
At new moon the lit side faces away from us, so it is almost invisible.
- Fill the blankLevel 1
21. The Moon takes about one ____ to go through all its phases.
- monthcorrect
- day
- hour
- year
The Moon's cycle of phases takes roughly a month.
- Match the pairsLevel 1
22. Match each Moon phase to how it looks.
Answer: Full moon = Bright round circle; New moon = Almost invisible; Crescent moon = Thin curved sliver
Each phase shows a different amount of the Moon's lit side.
- Multiple choiceLevel 1
23. When the Moon looks like a full bright circle, what is that phase called?
- Full mooncorrect
- New moon
- Crescent moon
- Half moon
A full moon is when we see the whole lit side of the Moon as a round circle.
- Odd one outLevel 1
24. Which of these is NOT a phase of the Moon?
- Sunrisecorrect
- Full moon
- New moon
- Crescent moon
Sunrise is about the Sun and Earth's spin, not a Moon phase.
Why We Have Seasons
- Build the sentenceLevel 1
25. Build a true sentence about why seasons happen.
Answer: Seasons happen because Earth is tilted
Earth's tilt is the reason we get seasons.
- Choose all that applyLevel 1
26. Which of these are seasons of the year?
- Springcorrect
- Wintercorrect
- Morning
- Weekend
Spring and winter are seasons; morning and weekend are not.
- Fill the blankLevel 1
27. When your part of Earth tilts away from the Sun, it is ____.
- wintercorrect
- summer
- spring
- noon
Tilting away means less sunlight, which brings cold winter.
- Multiple choiceLevel 1
28. Why does Earth have seasons?
- Earth is tilted as it orbits the Suncorrect
- Earth gets much closer to and farther from the Sun
- The Sun changes size
- The Moon blocks the Sun
Earth is tilted, so different parts get more or less sunlight through the year.
- Fact or fibLevel 2
29. The two halves of Earth have opposite seasons at the same time.
Answer: True
When the north tilts toward the Sun, the south tilts away, so they are opposite.
- Match the pairsLevel 2
30. Match each season to how its days feel.
Answer: Summer = Longest days; Winter = Shortest days; Spring = Days getting longer
Summer has the longest days, winter the shortest, and spring days get longer.
Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.
How you practise
This unit mixes 14 different question formats, so you are recalling and applying rather than recognising the same layout every time.
- Build the sentence
- Choose all that apply
- Fact or fib
- Fill the blank
- Guess the number
- Match the pairs
- Multiple choice
- Odd one out
- Picture question
- Put in order
- Sort into groups
- Spell it
- True or false
- Type the answer
Practise The Moon, Earth and Seasons
120 questions across 21 steps. Start with step one and crawl at your own pace.
Play this unitRead about The Moon, Earth and Seasons
Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.
- Why Earth Has SeasonsSeasons come from Earth's tilted axis, not from large changes in distance from the Sun. The tilt changes the angle and length of daylight through the year.July 24, 2026 · 5 min read
- Why Does the Moon Have Phases?Why does the moon have phases? It is not Earth's shadow. Here is how the changing angle of sunlight produces the full cycle from new moon to full.August 28, 2026 · 5 min read
- Why Does the Moon Always Show the Same Face?The Moon rotates once per orbit, so the same side always faces Earth. How tides locked it in place, what the far side looks like, and why it is not dark.September 14, 2026 · 5 min read
- How Solar and Lunar Eclipses HappenEclipses happen when the Sun, Earth and Moon line up closely enough for one body to enter another shadow. The Moon's tilted orbit explains why this does not happen every month.July 26, 2026 · 5 min read
More units in Astronomy & Space
- The Day and Night SkyThe Sun, Moon, stars, day and night, and constellations
- Our Solar SystemThe Sun, the planets, their order, and dwarf planets
- Rockets and AstronautsRockets, astronauts, the Moon landing, satellites and telescopes
- The Planets in DepthEach planet's features, atmospheres, rings and moons
- The Sun and StarsWhat stars are, star types, brightness, colour and distance
- Moons, Asteroids and CometsMoons, asteroids, comets, meteors and the outer belts
- Gravity and OrbitsGravity, orbits, Kepler's laws, tides and weightlessness
- Telescopes and ObservingHow telescopes work, their types, wavelengths and observatories