Why the moon has no atmosphere ?

Explanation

### Step-by-Step Solution:

1. **Understanding Atmosphere**: An atmosphere is a layer of gases that surrounds a planet. It is held in place by the planet's gravitational pull.

2. **Gravitational Pull**: The gravitational force of a planet is responsible for keeping the gases from escaping into space. This force pulls the gas molecules towards the planet.

3. **Escape Velocity**: Each celestial body has a specific speed known as escape velocity. This is the minimum speed required for an object to break free from the gravitational pull of the planet.

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