Planetary core has an observed magnetic field, which is believed to be generated within its metallic core. Mercury's core occupies 85% of the planet's radius, making it the largest core relative to the size of the planet in the Solar System; this indicates that much of Mercury's surface may have been lost early in the Solar System's history. Mercury has a solid silicate crust and mantle overlying a solid iron sulfide outer core layer, followed by a deeper liquid core layer, and then a possible solid inner core making a third layer. The composition of Venus' core varies significantly depending on the
What Shall We Do Now? the form of a fist that becomes a hammer (a hammer that would reappear in the animated sequence of "Waiting for the Worms"). "What Shall We Do Now?" would be performed at all concerts for "The Wall", and so appears on "Is There Anybody Out There? The Wall Live 1980–81". It was also included in Waters' 1990 "The Wall" Concert in Berlin, therefore appears on the album "The Wall – Live in Berlin". Waters also performed it on his 2010-2013 tour. What Shall We Do Now? "What Shall We Do Now?" (working title "Backs to the Wall") is a song