The atmosphere forms a protective blanket around Earth and makes it a habitable planet for life. It is the air we breathe and plays a key role in the weather we all like to complain about.
The atmosphere encompass all the gases that swirl around the Earth.
The blue colour of the sky is because of dispersion and absorption of the Sun's radiation by molecules in the atmosphere.
The red colour in the morning and the evening is because of particles, such as dust, smoke or ash.