SOLAR SYSTEM

Detailed explanation-1: -The inner core is a hot, dense ball of (mostly) iron. It has a radius of about 1, 220 kilometers (758 miles). Temperature in the inner core is about 5, 200° Celsius (9, 392° Fahrenheit).

Detailed explanation-2: -It’s generally well known that the innermost part of Earth is made mostly of iron (about 85%). Nickel accounts for about 10%. That last 5% however, has remained a bit of a mystery.

Detailed explanation-3: -It is widely accepted that the Earth’s inner core formed about a billion years ago when a solid, super-hot iron nugget spontaneously began to crystallize inside a 4, 200-mile-wide ball of liquid metal at the planet’s center.

Detailed explanation-4: -The core is the centre of the earth and is made up of two parts: the liquid outer core and solid inner core. The outer core is made of nickel, iron and molten rock.

Detailed explanation-5: -Between 85 and 90 percent of Earth’s iron is concentrated in the core. The increasing pressure with depth causes phase changes in crustal rocks at depths between 5 and 50 km (3 and 30 miles), which marks the top of the upper mantle, as mentioned above.