The Moon doesn't actually get bigger, but it *appears* bigger at certain times due to its orbital path and our perspective from Earth. This phenomenon is called the Moon Illusion.

Here's why it happens:

* Orbit: The Moon's orbit around Earth is elliptical, meaning it's not a perfect circle. It's closer to Earth at its perigee (closest point) and farther away at its apogee (farthest point).

* Perspective: When the Moon is closer to the horizon, our brains perceive it as larger than when it's high in the sky. This is likely due to a combination of factors:

* Atmospheric distortion: The atmosphere bends light, making objects near the horizon appear larger.

* Depth cues: Our brains use objects on the ground as reference points, making the Moon appear closer and therefore larger when near the horizon.

* Relative size: The Moon appears larger when next to other objects on the ground, like trees or buildings, compared to when it's high in the sky and surrounded by empty space.

Supermoons:

There's also a real phenomenon called a supermoon, which happens when the full moon coincides with its perigee. This makes the Moon appear slightly larger and brighter than usual, but it's not as dramatic as the Moon Illusion.

So, while the Moon doesn't physically change size, its apparent size can vary due to its orbit and our perception.