††††A celestial globe shows the positions of the stars in relation to the Earth, if the Earth is taken to be an imaginary point at the centre.
The first celestial globe, which was taller than a man, was probably that devised by the ancient Greek geographer and astronomer Ptolemy, who lived from about 100 to 170 AD. Ptolemy used his observations of the stars to draw maps of the constellations on his globe. It was Ptolemy who developed the theory that the Earth is the centre of the universe, with the sun, moon and stars revolving around it.
Another form of celestial globe was an instrument called the armillary sphere. This was invented by Italian scientists in the 15th century. It consisted of a skeleton sphere with the Earth in the centre, and was used to measure the positions of the stars in the night sky.
