ASTRO-110 Lecture Notes - Lecture 29: Gravitational Energy, Solar Wind, Outer Core
9 Oct 2020
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Document Summary
Many things can reshape earths surface: volcanoes, earthquakes, asteroids, comets, and many gradual effects. Mercury and the moon still show scars from the heavy bombardment. Features have been shaped by running water. Most direct data comes from seismic waves. Density of its surface rock tells us how much denser it must be inside. All the terrestrial words have layered interiors into 3 categories: Crust: lowest density rock, such as granite and basalt. Earths metallic core has two distinct regions: solid inner core, and molten (liquid) outer core. A planets lithosphere is its outer layer of cool, rigid rock. Differentiation: results in layers made of different materials. Two major processes explain why all the terrestrial worlds once had hot interiors: Interior heat is the primary driver of geological activity. Convection: when hot material gradually expands and cools as it rises upward. Planetary size determines how long a planet stays hot.
