A gas in the upper part of Eath's atmosphere?

The upper part of Earth's atmosphere primarily contains a mixture of gases, with nitrogen and oxygen being the most abundant in the lower layers, while the upper layers feature lighter gases such as helium and hydrogen. The thermosphere, for example, contains ionized gases that can create phenomena like the auroras. Additionally, this region is where satellites orbit and where the atmosphere transitions into outer space. The composition and behavior of these gases are influenced by solar radiation and cosmic events.