The astrolabe was part of the royal collection of Maharaja Sawai Man Singh II of Jaipur, then passed to his wife Maharani Gayatri Devi, and later moved to a private collection during her lifetime. It was made in the early 17th century in Lahore (now Pakistan) by brothers Qa'im Muhammad and Muhammad Muqim for a Mughal nobleman. Only two astrolabes are known to have been jointly made by the brothers; the other, smaller one is kept in a museum in Iraq. The astrolabe was commissioned by Aqa Afzal, a nobleman who administered Lahore under Mughal emperors Jahangir and Shah Jahan.
Astrolabes are metallic disks with multi-layered, interlocking components historically used for timekeeping, star mapping, determining the direction of Mecca, and tracking sky motion. They were first developed in ancient Greece in the 2nd century BCE and spread to the Islamic world by the 8th century. According to BBC News - Science, Benedict Carter described the astrolabe as weighing 8.2 kg, measuring nearly 30 cm in diameter, and standing about 46 cm tall, almost four times the size of a typical 17th-century Indian astrolabe. Sotheby's reports that the astrolabe contains 94 cities inscribed with longitudes and latitudes, 38 star pointers with floral tracery, and five precision-calibrated plates with degree divisions down to a third of a degree.
perhaps the largest in existence
It weighs 8.2kg, measures nearly 30cm in diameter and stands about 46cm tall - almost four times the size of a typical astrolabe from 17th Century India.