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
Fear of a Black Planet Fear of a Black Planet Fear of a Black Planet is the third studio album by American hip hop group Public Enemy. It was released on April 10, 1990, by Def Jam Recordings and Columbia Records. For the album, Public Enemy's Bomb Squad production team sought to expand on the dense, sample-layered sound of the group's 1988 record "It Takes a Nation of Millions to Hold Us Back". Having fulfilled their initial creative ambitions with that album, Public Enemy aspired to create what lead rapper Chuck D called "a deep, complex album". Their songwriting was partly inspired by the controversy