The Equator is an imaginary circle drawn around a planet at a distance halfway between the poles. The equator divides the planet into a Northern Hemisphere and a Southern Hemisphere. The latitude of the equator is, by definition, 0°. The length of Earth's equator is about 40 075.0 km, or 24 901.5 miles. Exact length of equator is 40 075 016.6856 m in WGS-84, and 40 075 035.5351 m in IAU-2000.
The equator is one of the five main circles of latitude based on the relationship of the Earth's rotation and plane of orbit around the sun. Additionally, the equator is the only line of latitude which is also a great circle.
The Sun, in its seasonal movement through the sky, passes directly over the equator twice each year on the March and September Equinoxes. At the equator, the rays of the sun are perpendicular to the surface of the earth on these dates.
Places near the equator experience the quickest rates of sunrise and sunset in the world, taking minutes. Such places also have a constant amount of day/night time (12 hours of each) on every day throughout the year.
Locations near the equator are good sites for spaceports, as they are already moving faster than any other point on the Earth due to the Earth's rotation, and the added velocity reduces the amount of fuel needed to launch spacecraft.
Temperatures around the equator are high all year round. In many tropical regions people identify 2 seasons, wet and dry, but most places very close to the equator are wet throughout the year, although seasons can vary depending on a variety of factors including elevation and proximity to an ocean.
Journeys trips that include the Equator:
Quito Colonial City and the Equator trip extension
Information based on http://en.wikipedia.org/wiki/Equator