It may be only an imaginary line bisecting an imaginary plane, but the equator does more than simply divide the Northern and Southern hemispheres. For starters, it’s the line of demarcation for the seasons in each hemisphere. It’s also the widest place on the planet because the Earth bulges slightly at the equator. And it’s the place with the fastest sunrises and sunsets on the planet because the sun moves perpendicularly to the horizon at the equator. But the actual length of each day is constant throughout the year, with the days appearing to last longer than nights because of a unique atmospheric refraction that happens at this latitude. In spite of its enormous importance in gravitational pull and its impact on our seasons, the actual location of the equator isn’t fixed—it typically drifts about nine meters (30 feet) every year.