ASTA01H3 Chapter : Earth
Document Summary
I ntro to astronomy and astro part i. earth"s radius is about 6400km: dividing these together, we find that earth"s average density is 5500 kg/. we can conclude that because the surface layers have densities much less than average, much denser material must lie deeper. mixture of gases: nitrogen 78, oxygen 21, argon 0. 9, carbon dioxide 0. 03, water vapour varies from 0. 1 to 3% www. notesolution. com. T roposphere: the portion of the atmosphere below about 12km (weather zone) stratosphere: above the troposphere to an altitude of 40 to 50km. mesosphere: 50 to 80km from earth"s surface. Where the atmosphere is kept partially ionized by solar ultraviolet radiation. atmospheric densities decrease steadily with increasing altitude. The troposphere is the region of earth"s (or any other planet"s) atmosphere where convection occurs. convection: the constant rising of warm air from the earth"s surface and the concurrent downward flow of cold air to replace it.
