What gaseous species are present in the mesosphere and thermosphere ?

Explanation

To answer the question regarding the gaseous species present in the mesosphere and thermosphere, we will break down the information step by step.

### Step 1: Understanding the Atmosphere Layers
The Earth's atmosphere is divided into several layers based on temperature and altitude. The mesosphere and thermosphere are two of these layers.

### Step 2: Identifying the Mesosphere
The mesosphere is located above the stratosphere and below the thermosphere, typically ranging from about 50 km to 85 km above the Earth's surface.

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