Prime Meridian

From Pagenation

The Prime Meridian of the World (Zero Longitude). Greenwich England is where East meets West at the Greenwich Meridian (0° Longitude); World Time is set Greenwich Mean Time. The Meridian passing through the principal Transit Instrument at the Observatory at Greenwich was to be the ´initial meridian´. That all longitude would be calculated both east and west from this meridian up to 180°.

The Meridian Line is an imaginary line which runs from the North Pole to the South Pole. By international convention it runs through "the primary transit" instrument (main telescope) at the Royal Observatory in Greenwich. It is known at Zero Longitude and it is the line from which all other lines of longitude are measured. This includes the line that runs 180° away from Greenwich also known as the International Date Line.

Equator

The equator is an imaginary circle drawn around a planet (or other astronomical object) at a distance halfway between the poles. The equator divides the planet into a Northern Hemisphere and the Southern Hemisphere. The latitude of the equator is, by definition, Zero Latitute. The length of Earth's equator is about 40,075.0 km, or 24,901.5 miles. The surface of the Earth at the equator is mainly ocean. The highest point on the Equator is 4,690 m, at 77° 59' 31" W on the south slopes of Volcán Cayambe (summit 5,790 m) in Ecuador. This is a short distance above the snow line, and is the only point on the Equator where snow lies on the ground.

Interesting facts - places near the equator experience the quickest rates of sunrise and sunset in the world, taking minutes. Such places also have a relatively constant amount of day/night time on every day throughout the year compared with more northerly or southerly places.