AST251H1 Lecture Notes - Lecture 5: Circumstellar Habitable Zone, Escape Velocity, Solar Wind
16 Oct 2015
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Document Summary
How to lose an atmosphere: thermal escape particles of atmosphere have more energy and more escape velocity, none of the terrestrial planets gave enough mass = unable to keep hydrogen b/c of low escape velocity. Impacts: solar stirring: due to the solar wind, slow process, we are protected by our magnetic field. Magnetic field: a magnetic field is created when you set charged particles (electrons) in motion, battery creates a current. Ways of losing atmospheres: we are protected by earth"s magnetosphere created by earth"s magnetic field- deflects most charged solar wind particles, why do we have a magnetic field, conducting fluid (mantle, convection, moderate rotation. Climate regulation: earth"s climate is stable (with some exceptions, we are a goldilocks planet = liquid water. What is life: we have no good definition of life, start by describing attributes. The cell: basic structure of life on earth: all life on earth is cellular, act as small chemical factories.
