Concepts in Astronomy #6. The Celestial Sphere

The Celestial Sphere

The Celestial Sphere is an imaginary sphere which contains the Earth. The radius of this sphere starts at the same point of Earth's radius, but it is longer. From an observer on the surface of the Earth, all the celestial objects are projected on this sphere. The stars have relatively fixed positions on the Celestial Sphere, with variations over many years mainly related to the precession movement of Earth. The planets' position on the Celestial Sphere varies according to the movement of the planets while they orbit the Sun.

Previous Posts

Concepts in Astronomy #1. Introduction
Concepts in Astronomy #2. The Ecliptic
Concepts in Astronomy #3. The Celestial Equator
Concepts in Astronomy #4. Right Ascension
Concepts in Astronomy #5. Declination

Credits

- Galaxy image obtained from Pixabay under CC0. No Copyright. The person who associated a work with this deed has dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law

- Rotating Earth GIF-file obtained from Wikipedia under CC BY-SA 3.0. Author:Tfr000