Long before there were planetariums or advanced technologies available for studying the sky, people devised ways of depicting the sun, moon, planets, and stars in relation to the Earth. There was a desire to learn about astronomical history and events; people wanted to figure out how Earth fit into the grand scheme of the universe. Globes helped to put objects into perspective, and served as scientific instruments, ornamental showpieces, and physical illustrations of the astronomy beliefs of the day.
Globes have been visual representations of the physical characteristics of Earth and Sky for thousands of years. Generally, there are three types of globes. Terrestrial globes detail geographical features of the Earth. There are also globes that illustrate the physical features of celestial bodies, such as the moon or Mars. Celestial globes, like the one pictured here, are spherical maps of the sky—models of the visible heavens.
There is written evidence that proves that the ancient world was familiar with the scientific principles necessary for depicting the celestial and terrestrial spheres, and the oldest known surviving ancient globe is the Farnese Atlas, now at the National Museum of Naples. The Farnese Atlas is a decorative celestial globe, about 25 inches in diameter, that shows the outline of constellations against a coordinate system. The statue of Atlas is dated 73 B.C.; the position of the constellation figures to the globe’s equinox date the globe itself to around 370 B.C. (Naturally, the ancient globes and models were representative of the astronomical ideas held at that period of time.)
As scientists and astronomers became more knowledgeable of the sky and objects in it, celestial globes became more detailed and accurate. The concept behind it is that the globe is a sphere that shows the Earth as its imaginary center on which the stars, constellations, and various astronomical circles are drawn. It is mounted in a harness that allows it to rotate and be tilted to different latitudes. There were a few problems with this type of globe, however; for example, it depicts the figures of the constellations facing outward, toward the user, rather than inward, toward the center of the globe.
A man named Erhardt Weigel built this celestial globe near the turn of the 18th century. He was a professor of Astronomy at the University of Jena in Germany. A lamp placed in the hollow center projected light out through the small holes punched in the embossed copper sphere. The stars are represented by these small holes, and by looking into the globe through one of four larger holes, the stars are seen in their correct configuration as points of light against a dark background. Thus, the globe is the earliest known in existence of the optical planetarium. Weigel’s model is dated 1699; it was acquired by The Franklin Institute in June of 1932 from Emil Hirsch of Munich, Germany.
The constellations Weigel used are not the standard ones, but ones he made up to depict the European royal families. Instead of the usual pagan figures, Weigel made the constellations into the arms of the ruling families. For example, the constellation Orion is a double-headed Austrian eagle.
Astronomy is one of the longest-studied sciences in history. Scientists have attempted to answer questions that seem far beyond our understanding for centuries. As long as we wonder about heavenly objects, some will try to recreate the nighttime sky with instruments such as the globe, lighting the world as the stars themselves do with their ideas, models, and theories.
Reference & Source for above: Instruments of Science: An Historical Encyclopedia New York & London, 1998 and The Franklin Institute.
Celestial Globe, Isfahan, Iran 1144.
Shown at the Louvre Museum, this globe is the 3rd oldest surviving in the world
Source : Wikipedia
The Farnese Atlas is a 2nd-century Roman marble copy of a Hellenistic sculpture of Atlas kneeling with the celestial spheres, not a globe, weighing heavily on his shoulders. It is the oldest extant statue of the Titan of Greek mythology, who is represented in earlier vase-painting, and more important, the oldest known representation of the celestial sphere. The sculpture is at the National Archaeological Museum in Naples, Italy. It stands seven feet (2.1 meters) tall, and the globe is 65 cm in diameter.
Atlas labors under the weight because he had been sentenced by Zeus to hold up the sky.
The globe shows a depiction of the night sky as seen from outside the outermost celestial sphere, with low reliefs depicting 41 (some sources say 42) of the 48 classical Greek constellations distinguished by Ptolemy, including; Aries the ram, Cygnus the swan and Hercules the hero. The Farnese Atlas is the oldest surviving pictorial record of Western constellations. It dates to Roman times, around AD 150, but has long been presumed to represent constellations mapped in earlier Green work.
Source : Wikipedia
Brass celestial globe, made by Muhammad ibn Hilal
Possibly from Maragha, north-west Iran, AD 1275-76 (AH 674)
‘The astronomer from Mosul’
Celestial globes were produced first by Greek astronomers, and later also in the Islamic world, where the earliest known globes date from the late eleventh century. Islamic astronomers built upon many of the achievements of classical Greek science, further refining concepts and the design of astronomical instruments, such as the celestial globe and the astrolabe. This is why an Islamic globe depicts the classical constellations, such as the Great Bear, Pegasus, Orion and the twelve signs of the zodiac.
At the South Pole of this globe, the craftsman has inscribed his signature: ‘Made by the most humble in the supreme God, Muhammad ibn Hilal, the astronomer from Mosul, in the year 674’ (AD 1275-76). Mosul is an important city in northern Iraq, famous in the first half of the thirteenth century for its skilled metalworkers. However, this globe may not have been manufactured in Mosul. In 1262, the city was sacked by the Mongols. The invading force was led by Hulagu Il-Khan (died 1265), who had recently founded an important observatory at his new capital of Maragha, in north-western Iran. The Mongols were known to deport skilled citizens from conquered lands, and Hulagu may have decided to send Muhammad ibn Hilal to the new observatory straight away. The globe, constructed some twelve years later, may therefore have been constructed at Maragha.
R. Pinder-Wilson, ‘The Malcolm celestial globe’, British Museum Yearbook-2, 1 (1976), pp. 297-321 (reprinted in Studies in Islamic Art, Pindar Press, London, 1985) Source : The Trustees of the British Museum
Argo Navis (which means ‘the ship Argo’) is a Southern constellation created by the Ancient Greeks, who pictured it as the ship in which Jason and the Argonauts sailed in search of the Golden Fleece.
Astronomers in the 18th century decided that it was too big to be just one constellation, so it was divided into 4 smaller ones: Puppis, (the Stern), Vela (the Sails), Pyxis (the Compass), and Carina (the Keel). These names are still in use today.
Celestial globe by Johann Schöner, c.1534