Atmosphere of Earth trend begin above 11 km, where the temperature stabilizes through a large vertical distance through the rest of the troposphere. In the stratosphere, starting above about 20 km, the temperature increases with height, due to heating within the ozone layer caused by capture of significant ultraviolet radiation from the Sun by the dioxygen and ozone gas in this region. Still another region of increasing temperature with altitude occurs at very high altitudes, in the aptly-named thermosphere above 90 km. Because in an ideal gas of constant composition the speed of sound depends only on temperature and not on the gas
Exposing Microorganisms in the Stratosphere stratosphere (31 km above sea level), 99.9% of the entire population was destroyed. According to the researchers, "most terrestrial bacteria would be inactivated within the first [day] on Mars if contaminated spacecraft surfaces receive direct sunlight." Of the 40 million spores exposed to the stratosphere, only 267 spores (or 0.0007%) remained viable. Extrapolating this, no viable spores would remain if flight samples had an additional 150 minutes of Sun exposure in the stratosphere (630 min total time). The survivors showed three single nucleotide (base pair) substitutions compared to unexposed controls kept on the ground. These three coding regions are associated