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
Imiloa Astronomy Center of Hawaii gift shop, and Sky Garden café are open to the public Tuesday through Sunday. An evening "Maunakea Skies" star talk is held in the planetarium on the last Saturday of each month. In the Hawaiian language, ‘Imiloa means "exploring new knowledge." It is located at 600 ‘Imiloa Place in Hilo, just north of Hawaii Route 2000 (Pūʻāinakō Street). In September 2012 the Sagan Planet Walk, until then located only in Ithaca, New York, was extended with a statue representing Alpha Centauri installed at the Imiloa Astronomy Center. This made the Sagan Planet Walk the world's largest exhibition. Imiloa Astronomy Center