Crust (geology) Crust (geology) In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be distinguished based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Moon, Mercury, Venus, Mars, Io, and other planetary bodies formed via igneous processes, and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two
Faith in the Earth all. The Earth represents our one and only window of opportunity, at the same time as it symbolizes all of our unknown higher potentials. Neither spaceman nor God will come to save us. But this is not a bleak dystopian materialism, because just as our simian ancestors couldn't realize that the development of their vocal cords (something they already had at least in rudimentary form) would open up those new dimensions of reality that we call language, civilization, and culture, just so we ourselves cannot yet get our minds around what we might be able to do already in rudimentary