ASTRON 10 Lecture 17: Crust-Shaping Process, Impact Cratering
Document Summary
Features of the crust when the planet is starting to cool. Meteoroid shatters the ground beneath and produces shock waves. Older craters are more shallow (b/c of erosion) Erosion does not need an atmosphere to occur. Dust particles have positive charges --> levitate/repel one another. Tycho crater - the most recent prominent crater on the moon. Before 1960s, humans thought only the earth"s moon had craters. Found that other planets and moons have craters when we sent spacecraft to them. Central peaks are a lot higher than the original ground level and the rim of crater. Central peaks are present in some of mercury"s craters. Craters have central peaks and ejecta blankets too. Ejecta blankets - blankets of ejecta surrounding the crater. Ganymede"s surface is made of ice, not rock. Crater saturation - every square meter has been cratered many times over and every new crater overlaps an older one.
