Here's why:
* Reflection: Clouds are made up of water droplets or ice crystals, which reflect sunlight. This makes them appear white, especially when the sun is high in the sky.
* Contrast: Clouds stand out against the darker surface of the Earth, making them easily visible.
* Types of clouds: Different types of clouds have different appearances. Cumulus clouds appear fluffy and white, while cirrus clouds are thin and wispy.
You can see examples of clouds from space in many satellite images and photos taken by astronauts.