AST 102 Lecture 15: AST 102 – Lecture 15
Document Summary
So, we know more about earth than any other planet. As such, it is the central object in our study of comparative planetology. The evolution of the earth lays out the basic picture for the evolution of all terrestrial planets. The details differ (a lot) from case to case, but the general outline is pretty much the same. Once you make a rocky planet, then it will evolve according to the general pattern outlined below: Early terrestrial evolution: differentiation -- the material to form the planet collects, and retains sufficient heat (from bombardment and radioactivity) to melt. The denser (metallic) material settles to form the core, and the lighter (rocky) material forms the crust: the surface forms and hardens, and is subject to an early phase of intense cratering . The crust fractures due to both large impacts and vulcanism.
