Adjara is traversed by the northeasterly line of equal latitude and longitude. It is traversed by the northwesterly line of equal latitude and longitude. It is located at the latitude and longitude of . In considering temperature, location in terms of latitude and longitude is not a significant factor. Astrakhan is traversed by the northeasterly line of equal latitude and longitude. Knowledge of both latitude and longitude was required. Addresses are coordinates within the system (similar to latitude and longitude). Two levels of abstraction are employed in the definition of latitude and longitude. The first rigorous system of latitude and longitude lines is credited to Hipparchus. He developed a system of latitude and longitude. The grid formed by lines of latitude and longitude is known as a "graticule". The geographical mile is based upon the length of a meridian of latitude. Each meridian is perpendicular to all circles of latitude. Declination is analogous to terrestrial latitude. These represent perturbations in the Moon's ecliptic latitude.