A series of imaginary lines on the earth, that help in pinpointing a place’s location. These are called meridians and parallels. The equator is the first parallel line and also known as line 0 (zero degrees of latitude). The distance between any two meridians increases as we move away from the equator towards the poles. The equator and the lines that go up to the north and south poles are called parallels of latitude. There are 181 parallels of latitude.
The meridians of longitude on the other hand cut the parallels at right angles. These run east to west and the longest meridian is the Prime Meridian, which passes through Greenwich observatory. The value of this meridian is the origin of universal standard time. The meridians then go around the earth in 360 slices of 1 degree each.
This grid is used by cartographers, geographers and people who are interested in locating places. These imaginary lines help in determining the exact location of any point on the globe. The combination of the values of a place’s latitude and longitude, give us its geographical coordinates that can be used for navigation or even satellite positioning systems. The values of latitude and longitude are expressed in degrees, minutes and seconds. Each minute of a day is divided into 60 seconds. So, one minute of a day has 60 seconds, and so does each hour. Each of these fractions is subdivided into 60, hence the name of the unit of time we use to measure time – minutes and seconds.