Why We Can't See the Far Side of the Moon / Mr. Denjiro's Happy Energy!
DENJIRO: We're going to talk about the moon today. Do you know why there are different phases of the moon? Let me explain using this model in the studio. This camera represents the Earth. That light over there is the Sun. So, how does the moon look from Earth?
I have a model of the moon here. First, it's a full moon right here. We see a nice, round moon from Earth. We're going to move the moon in an elliptical orbit. Now, half of the moon is dark. This is known as "the last quarter." Let me move it some more. Here, it's a new moon, where it's completely dark. Now, the moon starts to gradually wax.
We're at the first quarter, where it's half full. The moon has made a full circle and returned to a full moon. The key here is how the sunlight shining on the moon looks from Earth. The moon waxes and wanes depending on the area covered by light.
The moon makes an elliptical orbit around the Earth. Even during full moons, the distance between the Earth and the moon differs slightly. When it's closest to the Earth and looks large, it's called a supermoon.
The moon rotates just like the Earth. But we can only see the same side of the moon from Earth, meaning we cannot see the far side of the moon. Why is that, you ask?
Let's say that this oval-shaped metal disk is the moon. The moon, too, has an oval shape, and bulges slightly toward the Earth. This magnet here represents the Earth. Let me bring it up to the moon. The magnetism is acting as the gravity that affects the moon. The side of the moon with the bulge is facing the Earth as it rotates. Since the Earth and moon are close and the moon has an oval shape, the same side of the moon is always facing the Earth due to Earth's gravity. This is known as "tidal locking."
If the moon were a perfect sphere, then there would be no tidal locking. Therefore, we'd be able to see the far side of the moon.
I hope energy will bring you all happiness. Our magic word is "Happy Energy!"