Equator
Imaginary line halfway between Earth's North and South poles
The equator is the circle of latitude that divides Earth into the Northern and Southern Hemispheres. It is an imaginary line located at 0 degrees latitude, about 21,639 nautical miles (40,075 kilometres; 24,902 miles) in circumference, located halfway between the North and South Poles. The term can also be used for any other celestial body that is roughly spherical.
From Wikipedia, under CC BY-SA. More on occurri.