![](https://stemazing.org/wp-content/uploads/2022/01/sun-earth-moon-model-pic-300x166.jpg)
A simple (not to scale) model of the sun, earth, moon system. Great for reinforcing the idea that a day is one earth rotation, a year is one revolution of the earth around the sun, and a lunar month (one revolution of the moon around the earth) is about 28 days.