Mesosphere

Definition of Mesosphere

The mesosphere denotes the third layer of Earth's atmosphere, occupying the space above the stratosphere and beneath the thermosphere. Spanning roughly 50 to 85 kilometers (31 to 53 miles) above the surface of Earth, it serves as the domain where the majority of meteors disintegrate upon entering the atmosphere.

Characteristics of the Mesosphere

Temperature: The distinctive feature of the mesosphere is the progressive decrease in temperature with ascending altitude. The uppermost stratum of the mesosphere, referred to as the mesopause, registers the lowest temperatures in Earth's atmosphere, dropping beneath -130 degrees Celsius (-202 degrees Fahrenheit).

Air Pressure: While air pressure in the mesosphere is exceedingly low compared to Earth's surface, it retains sufficient strength to decelerate and heat meteoroids entering the atmosphere.

Composition: Predominantly composed of nitrogen and oxygen, the mesosphere also encompasses minute ice particles. Moreover, this layer witnesses the disintegration of the majority of meteors upon atmospheric entry.

Phenomena in the Mesosphere

Meteors: Often dubbed the "meteor layer" of the atmosphere, the mesosphere is the region where most meteors combust due to friction with atmospheric particles. The visible trail of light, referred to as a "shooting star", represents the luminescent hot air generated as the meteor disintegrates.

Noctilucent Clouds: These highest atmospheric clouds inhabit the mesosphere. Their visibility is contingent upon being lit by sunlight from below the horizon while the Earth's surface and the lower layers of the atmosphere reside in Earth's shadow.

Exploration and Study of the Mesosphere

The mesosphere remains the least investigated layer of the atmosphere due to its altitude: too elevated for aircraft to access and too low for satellites to orbit. Consequently, research predominantly relies on ground-based radar, rocket data, and sporadic measurements from space shuttles.