The Earth is made of layers, each with its own unique characteristics and processes that make it a vital part of the planet. The solid inner core, for example, is the farthest layer from the planet's surface, yet it provides much of the heat needed to fuel dramatic surface phenomena such as volcanoes and earthquakes. Likewise, the outer core generates a magnetic field that protects the planet from harmful particles in space. In "Layers of the Earth", learn how scientists use modern tools like seismology, geodesy, computer modeling, and global positioning systems to study the workings of the inner Earth.