ASTRON 10 Lecture Notes - Lecture 10: Structure Of The Earth, Olivine, Basalt
Document Summary
Main difference between asteroids and comets is whether ice is on the surface or on not. Ice on the surface is necessary for outgassing(comets) Most things melt at approximately 1100 degrees in celsius. More vibrations and more particles = more heat. Dense materials acts as a heat shield, keeping more heat in. Heat of fusion is released, adding to the heat of the interior: sunshine, radioactivity. Creates a lot of heat (rtg from the martian: tidal stress and magnetic induction. Only truly prevalent on io, europa, amalthea, moons of jupiter. When stuff melts, more dense objects sink while less dense objects float: called differentiation, everything with enough gravity had to differentiate. Explains layering throughout stellar bodies throughout the universe: earth. Has average density of 7. 8, could have areas of 22 density at the very center. Made up of olivine, green crystalline rock. Average density of 3: all major solar bodies have concentric layers (including the moon)
