The coordinates system is used to map out and locate objects throughout space. In navigation, satellites use GPS signals to determine where you are relative to a grid placed on earth. This grid typically follows longitudinal and latitudinal lines. Space uses this system in a similar way. Engineers and astronomers use grids to determine the location of planets, stars, and other celestial bodies in the universe. Finally, archaeology uses grids to help map out a site that is being dug. As artifacts are recovered, archaeologists record their location on a coordinate grid because it helps them interpret the living conditions or other human behaviors on the site.