Atmosphere of Earth However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft. The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about , although this altitude varies from about at the geographic poles to at the Equator, with some variation due to weather. The troposphere is bounded above by the tropopause, a boundary marked in most places by a temperature inversion (i.e. a layer of
The World We Live In (Life magazine) by "The Epic of Man", focusing on the development and history of human civilization, and "The Wonders of Life on Earth", a series of articles tracing Darwin and evolution. Both of these were written by Barnett as well, and featured many of the same artists. "Life"'s series on the International Geological Year was hailed as a spiritual "update" to "The World We Live In". The World We Live In (Life magazine) The World We Live In appeared in the pages of LIFE magazine from December 8, 1952, to December 20, 1954. A science series, it comprised 13 chapters published on