The Earth's Atmosphere Today
Science: KS3, topic 2.5.13
The Atmosphere
The atmosphere is incredibly important. Without it, life on Earth would not exist.
The atmosphere
- The atmosphere contains the air that we breathe.
- It has changed over time but has been stable for around 200 million years.
- Our atmosphere protects us from the harmful ultraviolet (UV) rays emitted by the Sun.
Layers of the atmosphere
- The atmosphere can be split into the following layers (from bottom to top):
- Troposphere – where weather systems and clouds form.
- Stratosphere – aircraft fly just above the clouds in the stratosphere.
- Mesosphere – high altitude scientific balloons get to this layer.
- Thermosphere – this is the layer in which we see the northern lights.
- Exosphere – the very thin upper atmosphere layer that merges with space.
The composition of the atmosphere
- Our current atmosphere is made up of:
- 78% - nitrogen.
- 21% - oxygen.
- 0.9% - argon.
- 0.04% - carbon dioxide.
- 0.06% - traces of other gases such as methane and helium.
Test yourself on The Earth's Atmosphere Today
Layers of the Atmosphere
Components of the Atmosphere
What does the atmosphere protect us from?
Which gas makes up about 20% of the Earth's atmosphere?
Select the true statement in each pair