Sangeetha Pulapaka

Earth's innermost section is called its inner core, and is believed to be just as hot as the sun's surface. It was once believed that the earth's inner core was liquid, but Inge Lehmann - a seismologist - proved in theory in 1936 that the inner core was solid, and the outer core was liquid. The inner core is believed to be made up of an iron-nickel (metal) alloy. The earth, from the center moving outward, is made up of the inner core, the outer core, the lower mantle, the upper mantle, and the crust. Scientists continue to study the inner core, mostly through the use of seismic activity, as they try to learn more about it.

The inner core which is about 750 miles thick is made primarily of iron Unlike the outer core,the inner core is mostly solid Although the iron in the inner core is even hotter (10,000º F or more — as hot as the surface of the Sun!) than the outer core, the intense pressure from the rest of the planet is so great that the iron cannot melt.