Where Is Zero Degrees of Declination Found on the Celestial Sphere?

The term "celestial sphere" is used by scientists to describe an imaginary and infinite globe with the Earth at its center. The sphere is used to establish coordinate systems to mark the positions of stars and other objects.

Earth's Axis

• The axis of the Earth is the imaginary line that runs from the north pole to the south pole. When this line is extended to infinity, it touches the celestial sphere at the north and south celestial poles.

Earth's Equator

• The equator of the Earth is the imaginary line that lies perpendicular to the Earth's axis at a point that is equally distant from both the north and south poles, running around the Earth's circumference and dividing the northern and southern hemispheres. This circle, when extended to infinity, divides the celestial sphere into halves, and is known as the celestial equator.

Latitude and Longitude

• In order to measure location on Earth, points called longitude and latitude are used. Longitude measures where a point fits along the equator; latitude measures where a point fits along the axis, in distance from the equator. When applied to the celestial sphere, latitude is measured by degrees and is known as declination.

Zero Degrees Declination

• Imaginary lines like Earth's equator are used to construct measurements for the celestial sphere. kiss image by Victor M. from Fotolia.com

  Zero degrees declination is any point that lies on the plane of the celestial equator.