 A very effective way to demonstrate why the moon has phases is to do this outside in the daytime when both the moon and the sun are in the sky. This may often be the case just before a sunset at a star party. The manual provides a more detailed presentation with a number of optional activities. Look under why does the moon have phases. Who can find the moon? Right there. Yep, there it is. Can you tell me why the moon has phases? Would you like to learn why it does? And see a demonstration? Okay. This is going to be your moon, alright? And your head is going to be the earth. Now where's the real moon again? Up there. And where's the real earth? Yeah, we're standing on it, right? And where's the real sun? Everybody point to the sun. Good job. Okay. Now take your moon and hold your moon right below the real moon. How much of your moon is lit up compared to the real moon? About the same. Yeah, it's about the same, isn't it? Well the moon orbits the earth this way. Let's start orbiting the moon around our head earth like this. Can you see the phases change on your moon? Yeah. Yeah. Okay, everybody stop at full moon. Good. Now let's keep on going around. And you have some more phases last quarter until you get a little crescent. And then when we're lined up with the sun, what do we have? The moon. Alright. Now keep on coming around and come back to where the moon is right now. Now how long does it take for the moon to go around once like that? About a month. About a month, right. That's why they call it a moonth, okay? Now the moon moves about 12 degrees of sky a day. Because 30 days and it goes in a circle approximately. So hold your hand out at arm's length. And from one side of your hand to the other is about 10 degrees of sky. Just stick your thumb out just a little bit and now you have 12 degrees. So put your thumb up against where the moon is right now. And look at the other side of your hand. That's where the moon will be tomorrow about this same time. Hold your moon up there and you can see what the moon will look like tomorrow about this same time, okay? And you can count how many days it is until full moon by just counting over with your hand. Alright. Great. Okay. And remember the lit side of the moon is always going to be pointing where. That's right. Now perhaps you've seen demonstrations of moon phases in a darkened room with a light in the middle of the room. When people compare the moon ball to the moon in the sky, they say it's tremendously more powerful and a very effective experience. Try it before your next star party.