Question

Define longitude.

Answer 1

Hint: In general, the fundamental planetary coordinate systems are defined relative to their mean axis of rotation further as various definitions of longitude that rely on the body. The longitude systems of most of these bodies with observable rigid surfaces are defined by references to a surface feature sort of a crater.

Complete answer:
Longitude refers to a geographic coordinate which specifies the east–west position of some extent on the surface of the world or the surface of a heavenly body. It refers to an angular measurement, generally expressed in degrees and is denoted by the Greek letter lambda (λ). Meridians (lines running from pole to pole) that connect points together with the identical longitude. The longitude that passes near the Royal Observatory, Greenwich, England, is defined as 0° longitude by convention. Positive longitudes are towards east of the longitude, and negative ones are towards the west.
Due to the earth's rotation, there's a detailed connection between the longitude and time. standard time (for example from the position of the sun) ranges with longitude, a difference of roughly 15° longitude that's like a one-hour difference in civil time. as compared with civil time to an absolute measure of your time allows longitude to be determined. Along with the time, absolutely the time is also obtained from a celestial event which is visible from both of the locations, sort of an occultation, or from a signal that's transmitted by telegraph or wireless. A location of north–south position together with a meridian is given by its latitude, that's round the angle between the local vertical and therefore the equatorial plane.
Longitude is sometimes given with the utilization of the geometrical or astronomical vertical. This will differ slightly from the gravitational vertical because of small variations in Earth's field of force.
Lines of the longitude appear vertical with ranging curvature during this map of the planet, but are literally halves of great ellipses, with identical radii at a given latitude.

Note:
Longitude is usually given as an angular measurement varying from 0° at the line of longitude to +180° eastward and −180° westward. The Greek letter λ (lambda), is referred to as to denote the situation of an area on Earth east or west of the longitude.
Each degree of longitude is specifically subdivided into hr, each of which is split into 60 seconds. A longitude is therefore laid out in sexagesimal notation as 23° 27′ 30″ E.