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,
What Shall We Do Now? sped up, to raise its key to E minor, with re-recorded vocals and guitar. The members of Pink Floyd have contributed to the confusion regarding the identity of this track, misidentifying "What Shall We Do Now?" as "Empty Spaces" on multiple occasions, such as in the track listing for the film version of "The Wall", and on Waters' "The Wall Live in Berlin". On other occasions (such as the officially released live version), the first and second parts of the track are divided and identified as "Empty Spaces" and "What Shall We Do Now?" respectively, even though they are in