Atmosphere and Planets in Our Solar System

Atmosphere and Its Layers

• Not all planets have an atmosphere; Mercury is the only planet in our solar system without one.
• The word "atmosphere" comes from "atmo-" meaning vapor and "-sphere" meaning round.
• Atmosphere is a protective barrier of gases surrounding the Earth.

Functions of the Atmosphere

• Protects us from solar radiation
• Protects from space debris
• Prevents water vapor and gases from escaping Earth

Layers of the Atmosphere

• Scientists discovered pauses in temperature change between layers, allowing them to separate the atmosphere into 5 distinct layers.

Troposphere

• Also known as the Biosphere, as it's where all living things are located on the Earth's surface
• Temperature decreases as you go higher in the Troposphere
• This layer is where atmospheric phenomena such as rain, storms, hail, and clouds occur

Risks of Higher Altitudes

• Decreased oxygen levels
• Lower air pressure
• Extreme temperatures make the atmosphere lethal at higher altitudes

Stratosphere

• Hotter than the Troposphere due to ozone molecules absorbing energy from UV rays
• Ozone layer absorbs radiation from the sun, preventing it from reaching the planet's surface

Ozone Layer

• Important for life on Earth, as it prevents radiation damage to plants, crops, humans, and skin
• Man-made CFC gases damaged the Ozone Layer, allowing more UV radiation to reach the surface

Other Layers

• Mesosphere: temperature decreases as you move away from the Ozone layer
• Thermosphere: low air density, so meteors do not burn here