<P> A galactic quadrant, or quadrant of the Milky Way, refers to one of four circular sectors in the division of the Milky Way . In actual astronomical practice, the delineation of the galactic quadrants is based upon the galactic coordinate system, which places the Sun as the origin of the mapping system . </P> <P> Quadrants are described using ordinals--for example, "1st galactic quadrant", "second galactic quadrant", or "third quadrant of the Milky Way". Viewing from the north galactic pole with 0 degrees (°) as the ray that runs starting from the Sun and through the Galactic Center, the quadrants are as follows: </P> <Ul> <Li> 1st galactic quadrant--0 ° ≤ longitude (l) ≤ 90 ° </Li> <Li> 2nd galactic quadrant--90 ° ≤ l ≤ 180 ° </Li> <Li> 3rd galactic quadrant--180 ° ≤ l ≤ 270 ° </Li> <Li> 4th galactic quadrant--270 ° ≤ l ≤ 360 ° (0 °) </Li> </Ul> <Li> 1st galactic quadrant--0 ° ≤ longitude (l) ≤ 90 ° </Li>

How many light years is earth from the center of the milky way