Knowledge Explorer lesson
The Sun, Moon, and Earth
Why do we have day and night?
The Sun is a star. It is a huge ball of hot, glowing gas that gives Earth light and heat.
Earth spins like a top. It makes one full turn about every 24 hours. When your side of Earth faces the Sun, it is day. When your side faces away from the Sun, it is night.
Earth also travels around the Sun. One trip around the Sun takes about 365 days: one year.
The Moon travels around Earth about once a month. The Moon does not make its own light. It reflects light from the Sun. Sometimes you can even see the Moon during the day!
What you will learn
- Explain that the Sun is a star
- Explain that Earth's spinning causes day and night
- Describe how Earth moves around the Sun and the Moon moves around Earth
Key facts
- The Sun is a star.
- Earth spins once about every 24 hours, causing day and night.
- Earth travels around the Sun once about every 365 days.
- The Moon reflects light from the Sun. It does not make its own light.
- The Moon travels around Earth about once a month.