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 Hill sphere, or gravitational sphere of influence, of Earth is about 1.5 Gm or 1,500,000 km in radius. This is the maximum distance at which the Earth's gravitational influence is stronger than the more distant Sun and planets.