Astronomy 1021 Lecture Notes - Lecture 7: Terrestrial Planet, Solar Wind, Subduction

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Jan Cami

Document Summary

Need internal heat to drive geology; heating and cooling mechanisms. Mars: all four geological processes; no active volcanism or tectonics; mars was wetter and warmer until 2-3 billion years ago. Thick atmosphere forces us to explore its surface through radar mapping. There are impact craters but not as much as other planets. Lava plains, shield volcanos and stratovolcanos on surface. All four geological processes are present on earth. Only terrestrial planet that shows plate tectonics. Sea oor is about 200 million years old. Plate tectonics drive resurfacing process on earth. Driven by size and largely destined from birth on. Atmosphere: layer of gas that surrounds a world. Creating pressure allowing liquids to exist on a planet"s surface. Interacts with solar wind to create magnetosphere. Characterized by two properties: chemical composition(which gases?) Weight of the atmosphere per square meter. Pressure in each layer is enough to hold up the weight of layers above.