It is a three-dimensional model of the universe for observation and measurement. The celestial sphere is an imaginary shell that surrounds the earth. All of the stars are represented on it. It will help us visualize the sky and how the appearance of the sky changes depending on where we are standing on the earth and what time of the year it is. Figures of the different constellations are engraved and labelled on the surface of this globe. Silver inlaid dots on the surface represent the stars. Here silver nails of 3 magnitudes indicate the star's position.  

This bronze celestial sphere has Persian inscriptions which states that it was made by Mohammad Salih of Thatta at the instance of Shaikh Abd al-Khaliq in 1660 CE.

Some 1018-star positions are marked on it with inlaid silver points, and several constellations are also engraved on the surface of the celestial sphere. Holes are made in such a fashion that the globe can be rotated around the equatorial axis and the ecliptic axis.

It doesn’t rest on a stand.
The celestial sphere is a practical tool for spherical astronomy, which deals with the determination of the positions of celestial bodies. As per belief of earth's spheroid shape, the celestial sphere or globe is made in spherical shape. Sphere is nearly an exact model of the earth; it has several cartographic advantages not offered by flat maps. The parallels and meridians used for location purposes can be correctly drawn, the scale is correct everywhere over the curved surface and the area and shape of continents and seas are accurately shown.

Emperor Humayun had a keen interest in astronomy and astrology, which sparked-off a legacy of interest and patronage of such scientific explorations in the Mughal dynasty. Astrolabes and celestial globes are important tools for astronomical and astrological calculations. Humayun was adept in making use of these highly sophisticated devices and utilised them to decipher auspicious hours before undertaking major life decisions. Understandably, he was a connoisseur and collector of these scientific instruments as well. It is noted that during his travels in Central Asia, in the Iranian city of Tabriz, he had ordered someone to go fetch a globe (kura) from the market. It was another matter, that the person misunderstood the request, and brought back some horses – mares and colts (kurra)! The emperor was amused and regarded this as a good omen.

Under Humayun’s patronage, the manufacturing of astrolabes and celestial globes took place. Unfortunately, no instrument survives from Humayun’s time.

Muhammad Saleh Thattvi (1074 AH/1663–64 AD), Mughal metallurgist, astronomer, geometer and craftsman, was born and raised in Thatta, Sindh province in Pakistan, during the reign of the Mughal Emperor Shah Jahan and the governorship of the Mughal Nawab Mirza Ghazi Beg of Sindh. During those years young metallurgists were recruited, patronized and delivered to the Mughal court at Agra.

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