lying out into space.So they know that the inner core is solid iron but why when the outer core is a liquid iron. Well as the depth increases in the earth then so does the pressure. So scientists put the solid middle down the fact that the pressure becomes too much for the liquid iron, so the pressure solidifies the core.Another point of evidence is the earth's magnetic field, again suggesting an iron core, because iron is a metal that can be magnetized. The magnetic field is thought to be in the liquid outer core, because of the readily movement, and iron been a good conductor. This is what may be required for a dynamo with the capacity to generate enough current to produce the earth's magnetic field. The liquid iron is thought be stirred in a motion by heat from the core. This action is thought to produce an electric current and therefore the magnetic field. This is another explanation as to the outer core been liquid, because if it wasn't then where would the magnetic field come from. As permanent magnetism cannot be kept with temperatures exceeding 500XC, however the outer core may well produce electric currents because of the free movement. The inner core would not be able to do this, as it is a solid....
