What is the Outer Core?
Deep below earth, or any other planet similar to earth, there is an outer core. The outer core is right under the mantel, and it is 2266 km thick. The outer core is believed to be made up of extremely hot liquid molten lava. The lava in the outer core is made up of mostly iron, and nickel. The outer core is on top of the inner core and like I said before, right under the mantel. Trust me, this is the part of earth you would never ever want to be in.
http://volcano.oregonstate.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers8.html
This video will start talking about the outer core at the start of 1:05