MCQ Detailed View

The mesosphere is the third layer of Earth’s atmosphere, lying above the stratosphere and below the thermosphere. Its altitude ranges from approximately 50 km to 85 km above the Earth’s surface. This layer is characterized by decreasing temperatures with increasing height, making it the coldest layer of the atmosphere, with temperatures dropping to as low as –90°C at the mesopause, which is the boundary between the mesosphere and the thermosphere.

The mesosphere plays a key role in protecting Earth from meteoroids. As meteoroids enter Earth’s atmosphere at high speeds, they collide with the thin gases in the mesosphere. This collision generates intense friction and heat, causing most meteoroids to burn up before reaching the surface. This is why meteors, or shooting stars, are visible in this layer.

The stratosphere lies below the mesosphere and contains the ozone layer, which absorbs harmful ultraviolet radiation. Above the mesosphere is the thermosphere, which has very low air density and experiences a sharp increase in temperature due to solar radiation. The mesosphere’s unique position allows it to act as a protective barrier, preventing space debris from impacting Earth regularly.

The boundaries of the mesosphere are important in atmospheric science and space studies. Understanding that it extends from 50 km to 85 km helps scientists calculate satellite orbits, meteor trajectories, and atmospheric pressure variations. Its low air density, extreme cold, and interaction with meteoroids make it distinct from other atmospheric layers.

This range of 50–85 km defines the mesosphere as a crucial part of Earth’s atmosphere, bridging the lower layers where weather occurs and the upper layers where satellites orbit and auroras appear.