The sky is the expanse of air that surrounds the Earth, appearing blue during the day due to the scattering of sunlight by the atmosphere. It contains various layers, including the troposphere, where weather occurs, and the stratosphere, which houses the ozone layer that protects us from harmful ultraviolet rays. At night, the sky becomes a canvas for stars, planets, and the moon. These celestial bodies are part of our solar system and can be observed with the naked eye or through telescopes. The sky also plays a crucial role in weather patterns and climate, influencing life on Earth.