Levels of Earth's Atmosphere

Earth's atmosphere is divided into five main layers, based on temperature changes with altitude:

1. Troposphere

  • Closest to Earth’s surface (0–12 km)

  • Where weather occurs (clouds, rain, storms)

  • Temperature decreases with height

  • Contains about 75% of atmospheric gases

2. Stratosphere

  • Extends from 12 to 50 km above Earth

  • Contains the ozone layer, which absorbs harmful UV rays

  • Temperature increases with height due to ozone absorption

  • Jet planes fly here because it's stable and has less turbulence

3. Mesosphere

  • Extends from 50 to 85 km

  • Coldest layer of the atmosphere

  • Temperature decreases with height

  • Where meteors burn up

4. Thermosphere

  • Extends from 85 to 600 km

  • Temperature increases sharply with height (can reach 2,500°C or more)

  • Contains the ionosphere, which reflects radio waves and causes auroras

  • Where the International Space Station orbits

5. Exosphere

  • Outermost layer (600 km and beyond)

  • Gradually fades into space

  • Very thin air, mostly hydrogen and helium

  • Satellites orbit here