Which layer of the atmosphere is known as the coldest layer?

The mesosphere is recognized as the coldest layer of the atmosphere. This is primarily due to the decrease in temperature with altitude that occurs in this layer, which extends from about 50 to 85 kilometers above the Earth's surface. In the mesosphere, temperatures can drop to as low as -90 degrees Celsius (-130 degrees Fahrenheit). This cooling effect is a result of the thinning of the atmosphere, combined with the limited absorption of solar radiation by the sparse air molecules present. As altitude increases within the mesosphere, there is less molecular density to absorb and retain heat, leading to these extreme low temperatures.

Understanding the temperature profiles of the different atmospheric layers is crucial for comprehending various weather phenomena and the behavior of satellites, which can often be affected by temperature and pressure changes as they orbit the Earth.