Armillary sphere

Uncommon card · No. 109241

An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (on the celestial sphere), consisting of a spherical framework of rings, centered on Earth or the Sun, that represent lines of celestial coordinate system and other astronomically important features, such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. It was invented separately, in ancient China possibly as early as the 4th century BC and ancient Greece during the 3rd century BC, with later uses in the Islamic world and Medieval Europe. With the Earth as center, an armillary sphere is known as Geocentric model . With the Sun as center, it is known as Copernican. The flag of Portugal features an armillary sphere. The armillary sphere is also featured in Portuguese heraldry, associated with the Portuguese discoveries during the Age of Discovery. Manuel I of Portugal, for example, took...

Read on Wikipedia · Image physical object: Jost Bürgi, Antonius Eisenhoit Photograph: Chris Bainbridge, Public domain