Also the second largest impact structure on Earth, the 1.85 billion years old Sudbury crater in Canada, hosts world-class mineral deposits - in this case nickel-rich minerals that were melted and concentrated by the extreme heating caused by the impact.
The circumference of Earth at the equator is about 24,902 miles (40,075 km), but from pole-to-pole â the meridional circumference â Earth is only 24,860 miles (40,008 km) around. This shape, caused by the flattening at the poles, is called an oblate spheroid.
The average radius of the Earth is 3,959 miles (6,374 kilometers). The equitorial diameter of the Earth (distance from one side of the Earth to the other at the equator) is about 7,926 miles. The ratio of the circumference to the diameter of a circle (circumference/diameter) is written as the symbol pi.