Thermosphere gas and the ionospheric plasma. The International Space Station orbits the Earth within the middle of the thermosphere, between . It is convenient to separate the atmospheric regions according to the two temperature minima at about 12 km altitude (the tropopause) and at about 85 km (the mesopause) (Figure 1). The thermosphere (or the upper atmosphere) is the height region above 85 km, while the region between the tropopause and the mesopause is the middle atmosphere (stratosphere and mesosphere) where absorption of solar UV radiation generates the temperature maximum near 45 km altitude and causes the ozone layer. The density
Atmosphere of Uranus exclusively in hydrogen deuteride molecules which it forms with normal hydrogen atoms. Infrared spectroscopy, including measurements with Spitzer Space Telescope (SST), and UV occultation observations, found trace amounts of complex hydrocarbons in the stratosphere of Uranus, which are thought to be produced from methane by photolysis induced by solar UV radiation. They include ethane , acetylene , methylacetylene , diacetylene . Infrared spectroscopy also uncovered traces of water vapour, carbon monoxide and carbon dioxide in the stratosphere, which are likely to originate from an external source such as infalling dust and comets. The Uranian atmosphere can be divided into three