The first of these is the equator. The equator, located at 0°, is the longest line of latitude on Earth at 24,901.55 miles (40,075.16 km). It is significant because it is the exact center of the Earth and it divides that Earth into the Northern and Southern Hemispheres.he equator is a line going around Earth and is halfway between the North and South Poles, it is given a latitude of 0°. Values increase north of the equator and are considered positive and values south of the equator decrease and are sometimes considered negative or have south attached to them.