Day and Night
📖 Learn
Every day, the sun rises in the morning and sets at night. But why does this happen? Let's learn about day and night and how Earth and the Sun work together!
What Causes Day and Night?
The Earth spins around like a top! This spinning is called rotation. When your part of Earth faces the Sun, it is daytime. When your part faces away from the Sun, it is nighttime.
Key Words to Know
- Sun: A giant ball of hot, glowing gas that gives us light and heat
- Earth: The planet we live on - it is shaped like a ball
- Rotate: To spin around like a top
- Day: The time when your part of Earth faces the Sun (light)
- Night: The time when your part of Earth faces away from the Sun (dark)
How Long is One Day?
It takes the Earth about 24 hours to spin around one complete time. That is why we have 24 hours in a day! One spin equals one day and one night.
💡 Examples
Let's explore day and night with examples.
Example 1: The Spinning Ball
Imagine shining a flashlight on a ball in a dark room.
- The flashlight is like the Sun
- The ball is like Earth
- One side of the ball is bright (daytime)
- The other side is dark (nighttime)
If you spin the ball slowly, different parts go from light to dark!
Example 2: Morning Time
Question: Why does the sun seem to rise in the morning?
Answer: As Earth rotates, your part of the world turns to face the Sun. The Sun does not actually move up - we just spin toward it!
Example 3: Different Times Around the World
When it is daytime where you live, it is nighttime on the other side of the world!
Why? Because Earth is round. The Sun can only shine on half of Earth at a time.
Example 4: The Sun Sets
Question: Why does the sun seem to set at night?
Answer: As Earth keeps rotating, your part turns away from the Sun. The Sun does not go down - we spin away from it!
Example 5: Day and Night Activities
Daytime: We can see because the Sun lights up our part of Earth. We go to school, play outside, and do activities.
Nighttime: It is dark because our part of Earth faces away from the Sun. We use lights, rest, and sleep.
✏️ Practice
Answer these questions about day and night.
Problem 1
What gives us light during the day?
Show Answer
The Sun gives us light during the day.
Problem 2
Does the Sun move around the Earth, or does Earth spin?
Show Answer
Earth spins (rotates). The Sun stays in one place.
Problem 3
Why is it dark at night?
Show Answer
At night, our part of Earth is facing away from the Sun, so we do not get its light.
Problem 4
How long does it take for Earth to spin around one time?
Show Answer
It takes about 24 hours (one day and one night) for Earth to spin around once.
Problem 5
What does "rotate" mean?
Show Answer
Rotate means to spin around, like a top.
Problem 6
Is Earth flat or round like a ball?
Show Answer
Earth is round like a ball (a sphere).
Problem 7
When it is day where you live, what is it on the other side of Earth?
Show Answer
When it is day where you live, it is night on the other side of Earth.
Problem 8
What is the Sun?
Show Answer
The Sun is a giant ball of hot, glowing gas that gives us light and heat.
Problem 9
Name two things you do during the day.
Show Answer
Answers may include: go to school, play outside, eat lunch, read, do homework.
Problem 10
Why do we need to use lights at night?
Show Answer
We need lights at night because it is dark - our part of Earth is facing away from the Sun.
✅ Check Your Understanding
Answer these questions to see what you learned.
Question 1
Explain why we have day and night in your own words.
Show Answer
Earth spins around like a top. When our part faces the Sun, we have day (light). When our part faces away from the Sun, we have night (dark).
Question 2
Does the Sun really move across the sky?
Show Answer
No! The Sun seems to move across the sky because Earth is spinning. Earth rotates, not the Sun.
Question 3
What would happen if Earth stopped spinning?
Show Answer
One side of Earth would always face the Sun (always day), and the other side would always be dark (always night).
Question 4
Why is day and night important for people and animals?
Show Answer
Day gives us light to see and warmth. Night gives us time to rest and sleep. Many animals are active during day, and some are active at night.
🚀 Next Steps
- Watch the sunrise or sunset with a grown-up
- Use a flashlight and a ball to show how day and night work
- Notice what time the sun rises and sets this week
- Continue to the next lesson: Seasons and the Sun