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
Opus: The Day We Found Earth Opus: The Day We Found Earth Opus: The Day We Found Earth (stylized as OPUS: The Day We Found Earth) is an adventure game focused on story and exploration, developed by SIGONO (originally Team Signal), an independent game developer from Taiwan. It was first released on iOS and Android on October 22, 2015. A PC port was later released on Steam, available for Microsoft Windows and Mac OS X users. The game was nominated for Best Meaningful Play at the 12th International Mobile Gaming Awards on February 16, 2016. "OPUS: The Day We Found Earth" is an exploration adventure game