Globe - Celestial

Celestial

Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated.

A potential issue arises regarding the "handedness" of celestial globes. If the globe is constructed so that the stars are in the positions they actually occupy on the imaginary celestial sphere, then the star field will appear back-to-front on the surface of the globe (all the constellations will appear as their mirror images). This is because the view from Earth, positioned at the centre of the celestial sphere, is of the inside of the celestial sphere, whereas the celestial globe is viewed from the outside. For this reason, celestial globes may be produced in mirror image, so that at least the constellations appear the "right way round". Some modern celestial globes address this problem by making the surface of the globe transparent. The stars can then be placed in their proper positions and viewed through the globe, so that the view is of the inside of the celestial sphere, as it is from Earth.