Atmosphere of Earth (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. From highest to lowest, the five main layers are: The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at
A Planet Called Treason A Planet Called Treason A Planet Called Treason (1979) is a science fiction novel by Orson Scott Card. It was originally published by St Martin's Press and Dell Publishing Co. After being heavily revised, the book was republished under the title Treason (1988) by St. Martin's Press. The premise of this novel is the banishment to the seemingly metal-poor planet Treason of a group of people who attempted to create rule by an intellectual elite. The novel centers on the descendants of these anti-democratic thinkers who remain imprisoned on the planet. Through the ages, these descendants have formed nations which