hull@hao.UUCP (Howard Hull) (07/30/85)
from the Stardate series: > Earth has oceans because we're located at a favorable distance from the > sun -- close enough to keep the water from turning to ice, but far > enough to prevent it from boiling away. But the moon is located this > same distance from the sun -- so why doesn't it have any water? > > The reason is the moon's small size, or mass. The moon is smaller than > Earth, and its gravity is much weaker. Earth's stronger gravity keeps > our oceans from escaping into space as a gas. Hmmmmn. It should be possible to plot a graph of required mass versus radius from the sun, not only for water, but also for other common liquids such as carbon dioxide, ethyl alchohol and the old formula Coke. Of course, there are complications. The weight of a repressive atmosphere could be one, as well as could be the adiabatic lapse rate for those atmospheres that have lapses, for example. One could then plot each of the planets of the solar system on the same graph, and immediately tell how close we have come to having real live neighbors. Before I go to the trouble to try to compute all this stuff, has anyone, in their prowlings through various astrophysical articles, ever seen such a chart? Howard Hull [If yet unproven concepts are outlawed in the range of discussion... ...Then only the deranged will discuss yet unproven concepts] {ucbvax!hplabs | allegra!nbires | harpo!seismo } !hao!hull