We all know that the ozone layer is extremely important to Earth. It’s our ‘sunscreen’; it protects all beings on the planet from too much of the Sun’s ultraviolet rays. But did you know that the other layers of our atmosphere also have roles to play? Let’s find out what they are! 

• Earth’s atmosphere stretches up to as much as 10,000 kilometres above the surface of the planet. Beyond that, it blends with space. 
• The first layer of the atmosphere is the troposphere, which is about 7 to 15 kilometres above Earth’s surface. Human activities such as hot-air balloon and small aeroplane flights and mountain climbing take place in this layer. The troposphere is home to most of the atmosphere’s water vapour, dust and ash particles, which is why most clouds are located here as well.
• The stratosphere is the next layer, at about 15 to 60 kilometres above the surface. The ozone layer sits in the lower part of the stratosphere. The ozone layer is about 3 to 5 mm thick, but it changes with seasons and locations.
• The next layer is the mesosphere, which goes as far as about 85 kilometres above the surface. The air is thin here, but still thick enough for meteors to burn up as they pass through this layer. Shooting stars are nothing but burning meteors.
• The thermosphere is above the mesosphere. In this layer, temperatures increase with height. Radiation from the Sun makes the upper parts of the layer as hot as 2,000°C! But one wouldn’t feel hot because there aren’t enough gas molecules to transfer the heat. There aren’t enough molecules for sound waves to travel here either. This layer is home to the International Space Station and low Earth orbit satellites such as scientific satellites and some weather satellites.
• The uppermost layer, which blends with space, is the exosphere. Earth’s gravity is so weak here that gas molecules escape into space.
• A layer called the ionosphere overlaps the mesosphere, thermosphere and exosphere. It changes in size based on the energy it absorbs from the Sun. Parts of the ionosphere also overlap with Earth’s magnetosphere or magnetic field. High-energy particles from the Sun interact with charged particles in this layer and form auroras in the Poles, which are bright and colourful bands of light in the sky.

Sources: 

Ozone Layer Depletion | Penn State University 

Atmosphere | National Geographic Society 

Earth’s Atmosphere | NASA Space Place 

Catalogue of Earth Satellite Orbits | NASA