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? What Shall We Do Now? "What Shall We Do Now?" (working title "Backs to the Wall") is a song by Pink Floyd, written by Roger Waters. It was originally intended to be on their 1979 album "The Wall", and appeared in demo versions of "The Wall", but was omitted due to the time restraints of the vinyl format. In its place is a much shorter song, titled "Empty Spaces", which segues directly into "Young Lust". This was a last-minute decision; the album's sleeve notes still feature the song in its track listing, and include its lyrics. The beginning of the