Using these discs with balls representing the earth and moon and using the snake light sun We can show why eclipses don't happen every month For the best shadows use just the light without the ping pong ball You can also use a regular light bulb Now the size of the earth and the moon are to scale But they're too close to each other. They'd have to be about 30 inches apart on this scale We're also exaggerating the tilt of the moon's orbit so it's easier to see This model is tilted about 30 degrees The moon's orbit around the earth is actually tilted only about five degrees from earth's orbit around the sun So why don't eclipses happen every month? Well the earth's the moon's orbit is tilted compared to the earth's orbit around the sun Let's see what that means see the moon orbits the earth like this as the earth orbits the sun Now the earth orbits the sun wants every Good. Yeah, and the moon orbits the earth wants every month very good Now here's one for each of you So let's place each of you at a particular place Let's put you about here you're about here You're right about there and I'll be right here now We want all of our tilts to be in the same direction. You see that little dark black stripe on your on your earth Okay, everybody point them in this direction. So they're all parallel So pointing in that direction Got it got it. Let's get yours just tilted perfect a little bit more about like that good good Okay, we're all tilted the same way because it keeps that same tilt throughout the year Now let's see if anyone has a lunar eclipse now What position does the moon have to be in order for there to be a moon or a lunar eclipse in other words What phased does it have to be in full moon right that's right? So let's move your see I've got a move mine over here so that the moon is opposite The earth from the sun so everybody move your Your moon opposite the earth from the sun good. This is of course the sun This is representing the sun Very good. Okay, you've all got the right position now. Let's see. Let's check for lunar eclipses Let's see if I have a lunar eclipse Let's see. Oh, you see where my moon shadow is here and my earth shadow is above it So my earth shadow shadow does not hit the moon right? It's the moon shadow is below the earth shadow. So I'm not gonna get a lunar eclipse here Now, let's check your shadow Here's your moon and we'll get it into let's let's get your your earth nice and perpendicular there you go and There's your moon There it is at full position Look your shadows are aligned Your moon is in earth shadow. So you have You're right good Now let's check yours Now once you hold that there and let's see if we can find your shadow here there it is and We see that here's your earth shadow and there's your moon shadow Are you gonna have us a lunar eclipse? No, because your earth shadow your moon shadow is above your earth shadow Right, so So the tilt of earth's orbit So the tilt of the moon's orbit compared to the earth's orbit around the Sun is the reason that we don't have eclipses every month Now you can continue this by having your visitors move their moon around to new moon position and check for solar eclipses There are more tips and suggestions in the manual