mesosphere

American  

[mez-uh-sfeer, mes-, mee-zuh-, -suh-] / ˈmɛz əˌsfɪər, ˈmɛs-, ˈmi zə-, -sə- /

noun

1. (in the classification of the earth's atmosphere by chemical properties) the region between the ionosphere and the exosphere, extending from about 250–650 miles (400–1050 km) above the surface of the earth.

2. (in the classification of the earth's atmosphere by thermal properties) the region between the stratosphere and the thermosphere, extending from about 20–50 miles (32–80 km) above the surface of the earth.

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mesosphere British  

/ ˌmɛsəʊˈsfɛrɪk, ˈmɛsəʊˌsfɪə /

noun

1. the atmospheric layer lying between the stratosphere and the thermosphere, characterized by a rapid decrease in temperature with height

2. the solid part of the earth's mantle lying between the asthenosphere and the core

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mesosphere Scientific  

/ mĕz′ə-sfîr′ /

1. The region of the Earth's atmosphere lying above the stratosphere and below the thermosphere, from a height of about 50 km (31 mi) to about 80 km (50 mi) above the Earth's surface. In the mesosphere temperatures decrease with increasing altitude due to the decreasing absorption of ultraviolet radiation from the Sun. At the top of this region temperatures are around −95°C (−135.4°F). Most of the meteors that enter Earth's atmosphere burn up while passing through the mesosphere.

2. See also exosphere stratosphere thermosphere troposphere See illustration at atmosphere

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Other Word Forms

• mesospheric
  adjective

Etymology

Origin of mesosphere

First recorded in 1945–50; meso- + -sphere

Example Sentences

The mesosphere, an atmospheric region where space waste accumulates, is so difficult to study it has been called the ignorosphere.

From The Wall Street Journal • Jun. 11, 2026

Some material reached the lower mesosphere, more than 30 miles above the Earth's surface, altitudes never recorded from a volcanic eruption.

From Science Daily • Nov. 20, 2023

The top of the mesosphere is the coldest place in the atmosphere.

From Reuters • Nov. 3, 2022

Noctilucent clouds, also known as polar mesospheric clouds, appear during the summertime in each hemisphere at about 50 miles high in the layer of the atmosphere called the mesosphere.

From Washington Post • Jul. 2, 2022

Designed for patrol of the mesosphere, the ships were to have gained for the West control of near-Earth space, besides affording superior observation posts for Eastern developments and activity of a space nature.

From A Fine Fix by Dongen, H. R. van