Here's why:

* Gravity: The Earth's gravity pulls on the Moon, just like gravity pulls objects towards the Earth's surface.

* Orbital Motion: The Moon is moving forward at a high velocity. This forward motion is balanced by the pull of gravity. Instead of falling straight down, the Moon's forward motion causes it to constantly "miss" the Earth, resulting in a circular orbit.

* Constant Fall: Imagine throwing a ball horizontally. The ball will fall towards the ground in a curved path. The Moon is essentially doing the same thing, but on a much larger scale.

Let me know if you'd like to explore this further!