Here is the sun, a very small sun.
Here is the little moon. Isn't he a cute little moon!
Here is the little Earth. Ahh, what a sweet little Earth he is!
Can you see how the Sun's light shines on the Moon? It's faint but it's right there in the middle of the Moon's chest.
Hey, what happened? The Earth slowly moved in between the Sun's light and the Moon. The poor Moon is all dark now. You can see how hard the Earth had to concentrate to pull this off. Good job Earth.
Now, try not to miss the real lunar eclipse this evening!