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
Innovation and Its Discontents current debate about patents in historical terms, citing both times when patents were freely granted as royal favors, such as the Elizabethan era in England, as well as times when patents were impossible to obtain, or in the case of the Netherlands in the 1830s, completely abolished. Innovation and Its Discontents Innovation and Its Discontents: How Our Broken Patent System Is Endangering Innovation and Progress, and What To Do About It is a book () by Adam B. Jaffe and Josh Lerner. Princeton University Press published the book in 2004. The authors of the book outline changes made to the