Atmosphere of Earth sublimated into polar-mesospheric noctilucent clouds. These are the highest clouds in the atmosphere and may be visible to the naked eye if sunlight reflects off them about an hour or two after sunset or a similar length of time before sunrise. They are most readily visible when the Sun is around 4 to 16 degrees below the horizon. Lightning-induced discharges known as transient luminous events (TLEs) occasionally form in the mesosphere above tropospheric thunderclouds. The mesosphere is also the layer where most meteors burn up upon atmospheric entrance. It is too high above Earth to be accessible to jet-powered aircraft
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