Planetary Crusts Their Composition Origin And Evolution Cambridge Planetary Science -

planetary surface processes cambridge planetary science - planetary surface processes is the first advanced textbook to cover the full range of geologic processes that shape the surfaces of planetary scale bodies, chapter 2 fundamentals of planetary science - 2 2 origin of the elements before we consider the origin and evolution of the planets we must first discuss the nature and origin of the basic material of which they are composed the elements, comet astronomy britannica com - comet comet a small body orbiting the sun with a substantial fraction of its composition made up of volatile ices when a comet comes close to the sun the ices sublimate go directly from the solid to the gas phase and form along with entrained dust particles a bright outflowing atmosphere around