15. what is the core composed of? how do the inner core and outer core differ from each other? we can't sample the core directly, but geologists have studied samples of materials that are probably very similar in composition to the core. where do these samples come from? 16. what is the difference between a meteor and a meteorite? are all meteorites composed of the same material? explain your answer. 17. what is the difference between lithosphere and asthenosphere? which layer is softer and flows easily? at what depth does the lithosphere-asthenosphere boundary occur? is this above or below the moho?