what are the characteristics of the earth's inner core?
 The Earth's inner core is the Earth's innermost part. It is primarily a solid ball with a radius of about 1,220 kilometres, which is about 70% of the Moon's radius. It is composed of an iron–nickel alloy and some light elements. The temperature at the inner core’s surface is approximately 5,700 K, which is about the temperature at the surface of the Sun. 