Front view of a circular brass astrolabe. Engraved scales circle a pierced rotating star map.

Image: The Metropolitan Museum of Art, Open Access (public domain). Original record.

Objects / Planispheric Astrolabe
Object

Planispheric Astrolabe

A dated astronomical instrument made in Mashhad. The museum record identifies its materials and manufacture; the image lets us inspect its concentric scales, pierced rete, and compact case.

Institution
The Metropolitan Museum of Art
Accession
63.166a–j
Date
1065 AH / 1654–55 CE
Made in
Mashhad, Iran
Material
Brass and steel; cast and hammered, pierced and engraved
Dimensions
21.6 × 17.1 × 5.7 cm
Image rights
Public domain / The Met Open Access
Open museum record

What can be observed

The face is organized in nested circles. A pierced upper layer forms a map of stars over engraved plates, while a graduated ring marks the outer edge. A suspension fitting at the top indicates that the instrument could be held vertically.

Evidence boundary: these are visible features. Their names and astronomical function should be checked against the museum record and specialist sources rather than inferred from appearance alone.
Reverse of the astrolabe showing engraved circular scales and a straight rotating rule.
Reverse view. The straight rule and circular scales are recorded in a separate Open Access image from The Met.

Making and use

The Met describes the object as cast and hammered brass and steel, then pierced and engraved. It is a planispheric astrolabe: a portable instrument whose plates and rotating parts model positions on the celestial sphere for a chosen latitude.

This page does not claim a specific owner or journey before the object entered the collection; those details are not established by the fields used here.

Compare

Compare the 1291 Yemeni astrolabe →. It is larger across the case and is described as chased and silver-inlaid. The comparison asks how two instruments encode different locations and working practices.

Sources and revisions

Page created 8 October 2026 from the institution record. No independent claim of ownership history has been added.

Curator's evidence fileobjects / PLANISPHERIC-ASTROLABE

Planispheric Astrolabe

Image: The Metropolitan Museum of Art, Open Access (public domain). Original record .

Evidence register
ObserveDescribe material, form, marks, wear or spatial relation without assigning identity or purpose. Begin with “What can be observed.”
ContextLocate the record in excavation, collection, restoration and display history. Check the chain against Original record and Open museum record.
InferRead inscriptions, scale geometry, alloy, workshop practice and latitude-related design together, while keeping later ownership separate from original use. Tie every attribution to the feature that supports it and retain competing readings.
WithholdDo not extend “Making and use” beyond the date, sample, comparison or provenance actually documented.

Provenance checkpoint

List each custody or documentation gap separately; an unknown interval is evidence about the record, not permission to invent continuity.

Catalogue note

A dated astronomical instrument made in Mashhad. The museum record identifies its materials and manufacture; the image lets us inspect its concentric scales, pierced rete, and compact case. Mark later repairs, labels and digital reconstructions as later interventions rather than original features.

Research-room prompt

What single comparison object, technical test or archive entry would most change the interpretation of Planispheric Astrolabe?