Deutsch: Atmosphäre / Español: Atmósfera / Português: Atmosfera / Français: Atmosphère / Italiano: Atmosfera /

An atmosphere is the 500 km thick Layer of air surrounding the earth which supports the existence of all flora and fauna.
Other /More definition:
An Atmosphere is the mixture of gases surrounding the Earth. The Earth's Atmosphere consists of about 79.1\% nitrogen (by volume), 20.9\% oxygen, 0.036\% carbon dioxide and trace amounts of other gases. The Atmosphere can be divided into a number of layers according to its mixing or chemical characteristics, generally determined by its thermal properties (temperature). The layer nearest the Earth is the troposphere, which reaches up to an altitude of about 8 km (about 5 miles) in the polar regions and up to 17 km (nearly 11 miles) above the equator. The stratosphere, which reaches to an altitude of about 50 km (31 miles) lies atop the troposphere. The mesosphere which extends up to 80-90 km is atop the stratosphere, and finally, the thermosphere, or ionosphere, gradually diminishes and forms a fuzzy border with outer space. There is relatively little mixing of gases between layers.
Other /More definition:
Atmosphere is the whole mass of air surrounding the earth. See stratosphere, troposphere.