Here's why:

* Gravity: The Earth is much more massive than the Moon. This means it has a stronger gravitational pull. This pull is what keeps the Moon in orbit around the Earth.

* Centripetal Force: The Moon's movement around the Earth is not a straight line; it's a curved path. This curve is caused by the Earth's gravity pulling the Moon inwards. The Moon's forward motion (its inertia) prevents it from falling directly into the Earth. This balance between gravity and inertia is what creates the orbit.

Imagine you're swinging a ball on a string. The string is like the Earth's gravity, and the ball is like the Moon. The ball wants to fly off in a straight line, but the string pulls it inwards, causing it to move in a circle.

While the Moon's gravity does have a small effect on the Earth, it's not strong enough to cause the Earth to orbit the Moon. Instead, the Moon's gravity causes tides on Earth.