Astronomy 2232F/G Lecture Notes - Lecture 5: Escape Velocity, Gravitational Field, Volcanism
Document Summary
(cid:886). (cid:887)(cid:886) billion years ago all planets had identical atmosphere"s: planet doesn"t have this today. Today"s atmosphere=secondary: 95% h, 5% he =primary. Planets have very little of primary atmosphere left today. A large impact will blow out part of the atmosphere but thought to mainly be lost slowly. Two main ways you can get rid of an atmosphere: gravitational field strength, temperature of gas. Slide 6 things to escape: theoretically correct. It takes more energy to get something off the surface of the earth than the moon. Plot provides prediction of gases that should be in the atmosphere of a planet. As gravity increases it"s harder to launch something into space. Gas giants from other solar systems can keep all their gases because it"s harder for. Processes in the atmosphere of mars (chemical reactions) will destroy methane if methane is found it means it was produced recently because it"s composition is.