The starry sky is vast and awe-inspiring. Mastering the laws of the movement of celestial bodies is a dream that mankind pursues tirelessly, and the astrolabe is the crystallization of this dream. The word "astrolabe" means "holder" (lemma) of the "star" (astro). Using the stereographic projection, the astrolabe shows the basic diagram of the two-sphere cosmology. It is a multi-functional instrument integrating observation, demonstration, timing and calculation.​
 

The origin of the astrolabe is unknown, but it is generally believed to have originated in ancient Greece. It flourished in the Islamic world in the Middle Ages, and was later introduced to the Latin Europe and further popularized. The astrolabe reached Tsarist Russia in the north, spread to Africa in the south, and was introduced to China twice via land and sea. It is not only a representative of ancient astronomical instruments, but also a clear evidence of the technological and cultural exchanges between the East and the West.​
 

Tsinghua University Science Museum and History of Science Museum in Oxford University jointly organize this online exhibition in order to reveal the structure, principles, usage and historical variants of the astrolabe, and to show the unique charm of ancient astronomy.​