Crust (geology) formed almost immediately after formation of the Moon. Magmatism continued after the period of intense meteorite impacts ended about 3.9 billion years ago, but igneous rocks younger than 3.9 billion years make up only a minor part of the crust. 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,
The Public and its Problems the public and its potential. Dewey did not call for an abandonment of the public; rather, he hoped the public would regain a sense of self. The solution to this, he writes, is improved communication. Only then, with communication, will the public find itself and become a cohesive group. In addition to Dewey's proposition that the public cannot find itself because there are too many publics, he also blames the distractions of modern society. He points out that even in the past, the public has had other concerns than politics: "Political concerns have, of course, always had strong rivals". In