Atmosphere of Earth the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km (6,200 mi; 33,000,000 ft) where it merges into the solar wind. This layer is mainly composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen and carbon dioxide closer to the exobase. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another. Thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may
Gas-s-s-s ahead, write something, just keep the title."" "Gas-s-s-s" was an idea of Corman's, about a world where everybody over thirty had died. Corman later said "my first thought was to do a science fiction film with allegorical overtones." Armitage remembers the concept just being "a sentence, and that's what we went with ... He let you make it your own, and I did." Corman said that although "there was some good work in" Armitage's first draft, "the points I was trying to make in the script either did not come through or came through too obviously different parts, and it