Mantle (geology) Mantle (geology) The mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets (including Earth), a number of asteroids, and some planetary moons have mantles. The Earth's mantle is a layer of silicate rock between the crust and the outer core. Its mass of 4.01 × 10 kg is 67% the mass of the Earth. It has
What (ITS utility) What (ITS utility) What (typed as in the prompt) was a small information utility available in the Incompatible Timesharing System. It could provide information about incoming email, bus schedule on the MIT campus, executable source files or answer the user in a humorous manner. was written in the MIDAS assembly language. It can still be used on some of the ITS instances maintained across the web. The last traceable edit of the source code was by Ken L. Harrenstien on 16 May 1988. Without arguments would print information about inbox status: With the argument bus it would print out information