* Gravity: Earth's gravity keeps everything, including clouds, firmly attached to the planet.

* Cloud Formation: Clouds are made of tiny water droplets or ice crystals suspended in the air. They form when warm, moist air rises and cools, causing water vapor to condense.

* Atmospheric Layers: The atmosphere surrounding Earth has several layers, including the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Clouds primarily form in the troposphere, the lowest layer.

* Space's Vacuum: Space is a vacuum, meaning there is almost no air. If a cloud somehow managed to escape the atmosphere, it would immediately dissipate and its water droplets or ice crystals would freeze and scatter.

While clouds seem to drift and change shape, they remain within the Earth's atmosphere and are bound by gravity. They don't have the energy to escape into space.