Dictionary term
Astrolabe
Direct answer
Astrolabe: An Astrolabe is a historical astronomical instrument that combines a star map, coordinate projection, sighting scale, and rotating parts to solve problems involving altitude, direction, and time.
An Astrolabe is a portable analog model and calculator for the sky.
An Astrolabe is a portable analog model and calculator for the sky.
An engraved functional orientation; the page explains the real instrument, method, or publication.Quick reference
- Use when
- Use Astrolabe with the correct type and latitude plate, explaining which sight or rotation performs the intended calculation.
- Do not use it for
- Do not describe every astrolabe as a marine navigation instrument or imply that one surviving object represents all regional forms and uses.
- Reference category
- Historical Almanacs & Instruments
- Related terms
- Almanac, Astronomical Almanac, Nautical Almanac, Armillary Sphere
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The story behind Astrolabe
Planispheric astrolabes were developed and refined across Hellenistic, Islamic, European, and other scholarly and craft traditions over many centuries.
Astrolabe in spiritual tradition
The astrolabe is a meeting place of skilled hands, geometry, patient observation, and knowledge transmitted across cultures.
Astrolabe: fact and faith, kept distinct
This is a factual astronomy, calendar, Earth-science, cultural, or historical reference. It can support wonder at the created order without becoming a claim of fate, worship, or private revelation.
Astrolabe in numerology
Astrolabe is not a numerology claim. Any numbers attached to it should retain their ordinary scientific, calendrical, navigational, or historical meaning unless a separate symbolic interpretation is clearly labeled.
Why Astrolabe matters
It compresses celestial geometry into a hand-held instrument and illustrates how observation and mathematical design worked together before electronic computation.
Astrolabe at work: an example
A user can sight a star's altitude, set the rotating star map to that observation, and estimate local apparent time.
Where interpretation stops
Astrolabe is presented as sourced astronomy, calendrical, Earth-science, cultural, or instrument-history reference. Definitions should distinguish measured phenomena from civil convention and historical interpretation, preserve location and time dependencies, and avoid turning factual sky data into a deterministic personal claim.
Sources and editorial method
Research references used for this entry include:
- Smithsonian National Museum of American History: English Planispheric Astrolabe - Museum explanation of the astrolabe as an astronomical calculating and observing instrument.
- Royal Museums Greenwich: Astronomical and Navigational Instruments - Museum reference collection for astrolabes, armillary spheres, quadrants, nocturnals, sundials, and navigation instruments.
- Source
- The Great Almanac Dictionary
- Category
- Historical Almanacs & Instruments
- Also appears in
- Historical Almanacs & Instruments
- Aliases
- None listed
- Last updated
- 2026-07-15
Explore how an astrolabe works
Astrolabe in a book is one thing; Astrolabe in your own birth chart is your life. The Oracle casts your real chart and tells you what it means for your love, your work, and your year ahead, in conversation, free.
Speak with the OracleRelated terms
More in Historical Almanacs & Instruments
- Celestial Navigation
- Declination Table
- Heliometer
- Magnetic Compass
- Nocturnal Instrument
- Plumb Line
- Sight Reduction
- Water Clock
Common questions
What is Astrolabe?
An Astrolabe is a historical astronomical instrument that combines a star map, coordinate projection, sighting scale, and rotating parts to solve problems involving altitude, direction, and time.
How is Astrolabe used in an almanac?
Use Astrolabe with the correct type and latitude plate, explaining which sight or rotation performs the intended calculation.
What should I avoid when interpreting Astrolabe?
Do not describe every astrolabe as a marine navigation instrument or imply that one surviving object represents all regional forms and uses.
