A 1000-year-old star catcher | National Museums Scotland
Source: https://www.nms.ac.uk/discover-catalogue/a-1000-year-old-star-catcher
Archived: 2026-04-23 17:27
A 1000-year-old star catcher | National Museums Scotland
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News Story
Posted in
Long read
,
Written by
Dr Rebekah Higgitt
, Principal Curator of Science
This astrolabe was made by Muhammad ibn al-Ṣaffār in Córdoba in Al-Andalus (now Spain) during the period of Umayyad rule. It dates to the year 417 in the Islamic lunar calendar, which equates to 22 February 1026 to 10 February 1027 CE.
This means that in 2026 we are celebrating its 1000th anniversary.
Image gallery
Date information can be found in an inscription in 'Kufic'
,
a form of Arabic script, on the back of the instrument. This makes the astrolabe one of the earliest dated European-made astrolabes.
The inscription reads “Work of Muhammad bin [ibn] al-Ṣaffār in Córdoba in the year 17 and 400”.
The horizontal inscription, recording maker, place and date, on the back of the astrolabe. (
T.1959.62
).
What are astrolabes?
The origin of the astrolabe was probably ancient Greek, but the instrument as we know it dates to around the 8th century.
Astrolabes are a model representing the motions of the Sun and stars, as seen from the perspective of Earth. They are used to observe, calculate and predict the position of Sun and stars. Common purposes include time-keeping, wayfinding and astrology.
The word ‘astrolabe’ comes from the Greek 'astrolabes' (star-holder/taker). The 'rete' (net or web in Latin) is the rotatable front part of the device which points to stellar positions on the plate below and shows the ecliptic
(
annual path the Sun appears to take through the sky). The main body of the astrolabe is called the 'mater' (mother in Latin). This can hold several plates, engraved with stereographic projections of the celestial sphere as seen from different latitudes.
Astrolabes are 2D versions of the 3D model of the celestial sphere, known as an
armillary sphere.
They also have some similarity to planispheres, which are circular star charts. However, the changeable plates mean the astrolabe can be used at several different latitudes, and the additional lines and scales provide many more functions.
Astrolabes are used to observe the position of the stars to help calculate the time, date or position of the observer. For example, as well as establishing the correct time for daily prayer, the astrolabe could be used to work out the direction of Mecca. They can also be used to calculate the timing of celestial events, in the present, past or future, and to measure heights and angles on Earth.
To get a better idea of how an astrolabe works, you can play with
this simulation
, created by data scientist Alex Boxer. In
this YouTube video
, historian of science Taha Aslan shows how to calculate the time.
Anatomy of an astrolabe
There are two other surviving astrolabes signed by the same maker, Muhammad ibn al-Ṣaffār. One is dated 411 AH / 1020 CE and is
now at the Islamic Arts Museum in Malaysia
. The other is dated to 420 AH / 1029 CE and is
at the Staatsbibliothek zu Berlin
.
The 420 AH astrolabe, made in Toledo, includes added Hebrew script. This underlines the cultural and scientific interchange that took place in medieval Spain. The instrument is also the only one of the three to have its original rete
.
The rete on our instrument was made later, likely in the 13th century.
The rete is used in conjunction with changeable plates kept inside the body of the instrument. In the case of our 417 AH astrolabe, there are seven plates, engraved on both sides to be used at 14 different latitudes. These latitudes include locations such as Mecca, Medina, Córdoba, Tangier and Constantinople.
The engraving on the plates includes:
latitudes and place names
stereographic projections of the celestial sphere
lines indicating times for the five daily prayers
The back of the astrolabe is engraved with a shadow square, used to measure heights and calendrical scales, as well as the sighting vane, or 'alidade'.
The astrolabe unpacked to show the seven plates, the reverse of the mater, the central pin and the alidade
.
(
T.1959.62
)
The Ibn al-Ṣaffār brothers
The maker’s brother, also known as
Ibn al-Ṣaffār
, was a teacher of astronomy and geometry in Córdoba. He wrote a treatise on the use of the astrolabe, which was translated into Latin, Hebrew and Old Spanish. It was in use in Europe until the 15th century.
The brothers’ name is literally, and aptly, translated as 'son of a copper smith'. Brass is an alloy of copper and zinc, and in this case, the main body of the astrolabe has been calculated as around 80% copper and 20% zinc. This is a higher proportion of copper than became common in later brass objects.
A second-hand shop find
Before National Museums Scotland acquired it, this astrolabe belonged to James H. Farr, who ran Wardie Garage on Ferry Road. In 1959, Farr attended a lecture on astrolabes by Robert Plenderleith, Keeper of the Royal Scottish Museum’s Technological Department. This prompted him to have his astrolabe dated. On learning quite how old his astrolabe was, Farr decided to give it to the National Collection. He told The Scotsman that he “bought the astrolabe about ten years ago in a second-hand shop in Edinburgh’s Lawnmarket”.
The astrolabe was originally displayed with horological collections at the Museum. Today, it sits in the
Earth in Space gallery
, which shows how stars and planets have been observed and used for timekeeping and navigation.
In 2024-25 it was loaned to the British Museum’s
Silk Roads exhibition.
There, it was displayed with other artefacts from Córdoba during the period of Umayyad rule, showing its cosmopolitan nature and cultural flourishing.
The National Museums Scotland Ibn al-Ṣaffār astrolabe with other objects from the British Museum’s Silk Roads exhibition in 2025.
Credit: Rebekah Higgett
Table of places and latitudes on the plates
The seven plates serve the following latitudes.
Latitude
Place name
Notes (including modern values)
0⁰
[Equator]
This marks the line of the horizon
14⁰ 30’
Sana‘a
Sanaa, Yemen – 15°20′54″N
17⁰ 30’
Saba’
Ancient Kingdom of Sheba, in what is now Yemen, perhaps marking its northmost expansion
21⁰ 40’
Mecca
Mecca, Saudi Arabia – 21°25′21″N
25⁰
Medinah
Medina, Saudi Arabia – 24°28′12″N
28⁰
Qulzum
Ancient city in Egypt, also known as Clysma; Suez – 29°57′16.6″N
30⁰
Cairo
Cairo, Egypt – 30°2′40″N
32⁰
Qayrawān
Kairouan, Tunisia – 35°40′38″N
34⁰ 20’
Surra-man-raa
Samarra, Iraq – 34°11′54″N
36⁰
Tanja
Tangier, Algeria – 35°46′36″N
38⁰ 30’
Cordoba
Córdoba, Spain – 37°53′24″N
40⁰
Toledo
Toledo, Spain – 39°51′24″N
42⁰
Saragossa
Zaragoza, Spain – 41°39′N
45⁰
Constantinople
Istanbul, Turkey – 41°00′49″N – the high value of 45⁰ was traditionally used
66⁰
[Ecliptic]
The ecliptic represents the apparent annual path of the Sun, its poles are +66⁰ and -66.5⁰, also seen as the ends of the inhabited world
These places are paired on the plates:
Sanaa and Mecca
Medina and Samarra
Kairouan and Córdoba
Zaragoza and Equator
Sheba and Cairo
Clysma and Tangier
Toledo and Constantinople.
The Ecliptic plate is engraved inside the mater.
Table of stars carried by the rete
The pointers on the 13th-century rete have been calculated as pointing to 21 bright stars:
11 in the northern celestial hemisphere
12 in the southern celestial hemisphere
Here they are listed by position on the rete, east to west.
The 13th-century rete
.
(
T.1959.62
)
Star name
On rete
Translation
Bayer designati
Algol
ghūl
Arabic: [head of] the ogre
beta Persei
Aldebaran
al-dabarān
Arabic: the follower
alpha Tauri
Capella
‘ayyūq
Arabic: the goat
Latin: little goat
alpha Aurigae
Rigel
rijl al-jawzā
Arabic: foot of al-Jawzā (Orion)
beta Orionis
Betelgeuse
yad al-jawzā
Arabic: hand of al-Jawzā (Orion)
alpha Orionis
Sirius
al-yamāniya
Greek: glowing or scorching
Arabic: Yemeni [i.e. to the south]
alpha Canis Majoris
Procyon
al-sha‘āmiya
Greek: before the dog (Sirius)
Arabic: Shamiya [i.e. to the north]
alpha Canis Minoris
Regulus
qalb al-asad
Latin: prince or little king
Arabic: heart of the lion
alpha Leonis
Spica
al-a‘zal
Latin: [the virgin’s] ear of grain
Arabic: the unarmed
alpha Virginia
Alkaid
banāt [nash]
Arabic: the leader of the daughters of the bier
eta Ursae Majoris
Arcturus
al-rāmih
Greek: guardian of the bear
Arabic: the lancer
alpha Bootis
Alphecca
al-fakka
Arabic: [the brightest of] the broken [ring of stars]
alpha Coronae Borealis
Antares
qalb al-‘aqrab
Greek: rival to Ares
Arabic: heart of the scorpion
alpha Scorpii
Rasalhague
r’as al-hawwā
Arabic: the head of the serpent collector
alpha Ophiuchi
Vega
al-wāki‘
Arabic: the falling [eagle]
alpha Lyrae
Altair
al-ta’ir
Arabic: the flying [eagle
alpha Aquilae
Deneb
ridf
Arabic: tail
Arabic: hindmost or follower
alpha Cygni
Deneb Algedi
dhanab al-jady
Arabic: the tail of the goat
delta Capricorni
Markab
mankib
Arabic: saddle (markab) or shoulder (mankab) [of the horse]
alpha Pegasi
Caph
kaff al-khadīb
Arabic: the stained hand
beta Cassiopeiae
Diphda
dhanab quaytus
Arabic: frog
Arabic: the [southern] tail of the Cetus (sea monster)
beta Ceti
The astrolabe is on display in the Earth in Space Gallery on Level 1 at the National Museum of Scotland.
Written by
Dr Rebekah Higgitt
Principal Curator of Science
r.higgitt@nms.ac.uk
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Long read
Skip to main content
News Story
Posted in
Long read
,
Written by
Dr Rebekah Higgitt
, Principal Curator of Science
This astrolabe was made by Muhammad ibn al-Ṣaffār in Córdoba in Al-Andalus (now Spain) during the period of Umayyad rule. It dates to the year 417 in the Islamic lunar calendar, which equates to 22 February 1026 to 10 February 1027 CE.
This means that in 2026 we are celebrating its 1000th anniversary.
Image gallery
Date information can be found in an inscription in 'Kufic'
,
a form of Arabic script, on the back of the instrument. This makes the astrolabe one of the earliest dated European-made astrolabes.
The inscription reads “Work of Muhammad bin [ibn] al-Ṣaffār in Córdoba in the year 17 and 400”.
The horizontal inscription, recording maker, place and date, on the back of the astrolabe. (
T.1959.62
).
What are astrolabes?
The origin of the astrolabe was probably ancient Greek, but the instrument as we know it dates to around the 8th century.
Astrolabes are a model representing the motions of the Sun and stars, as seen from the perspective of Earth. They are used to observe, calculate and predict the position of Sun and stars. Common purposes include time-keeping, wayfinding and astrology.
The word ‘astrolabe’ comes from the Greek 'astrolabes' (star-holder/taker). The 'rete' (net or web in Latin) is the rotatable front part of the device which points to stellar positions on the plate below and shows the ecliptic
(
annual path the Sun appears to take through the sky). The main body of the astrolabe is called the 'mater' (mother in Latin). This can hold several plates, engraved with stereographic projections of the celestial sphere as seen from different latitudes.
Astrolabes are 2D versions of the 3D model of the celestial sphere, known as an
armillary sphere.
They also have some similarity to planispheres, which are circular star charts. However, the changeable plates mean the astrolabe can be used at several different latitudes, and the additional lines and scales provide many more functions.
Astrolabes are used to observe the position of the stars to help calculate the time, date or position of the observer. For example, as well as establishing the correct time for daily prayer, the astrolabe could be used to work out the direction of Mecca. They can also be used to calculate the timing of celestial events, in the present, past or future, and to measure heights and angles on Earth.
To get a better idea of how an astrolabe works, you can play with
this simulation
, created by data scientist Alex Boxer. In
this YouTube video
, historian of science Taha Aslan shows how to calculate the time.
Anatomy of an astrolabe
There are two other surviving astrolabes signed by the same maker, Muhammad ibn al-Ṣaffār. One is dated 411 AH / 1020 CE and is
now at the Islamic Arts Museum in Malaysia
. The other is dated to 420 AH / 1029 CE and is
at the Staatsbibliothek zu Berlin
.
The 420 AH astrolabe, made in Toledo, includes added Hebrew script. This underlines the cultural and scientific interchange that took place in medieval Spain. The instrument is also the only one of the three to have its original rete
.
The rete on our instrument was made later, likely in the 13th century.
The rete is used in conjunction with changeable plates kept inside the body of the instrument. In the case of our 417 AH astrolabe, there are seven plates, engraved on both sides to be used at 14 different latitudes. These latitudes include locations such as Mecca, Medina, Córdoba, Tangier and Constantinople.
The engraving on the plates includes:
latitudes and place names
stereographic projections of the celestial sphere
lines indicating times for the five daily prayers
The back of the astrolabe is engraved with a shadow square, used to measure heights and calendrical scales, as well as the sighting vane, or 'alidade'.
The astrolabe unpacked to show the seven plates, the reverse of the mater, the central pin and the alidade
.
(
T.1959.62
)
The Ibn al-Ṣaffār brothers
The maker’s brother, also known as
Ibn al-Ṣaffār
, was a teacher of astronomy and geometry in Córdoba. He wrote a treatise on the use of the astrolabe, which was translated into Latin, Hebrew and Old Spanish. It was in use in Europe until the 15th century.
The brothers’ name is literally, and aptly, translated as 'son of a copper smith'. Brass is an alloy of copper and zinc, and in this case, the main body of the astrolabe has been calculated as around 80% copper and 20% zinc. This is a higher proportion of copper than became common in later brass objects.
A second-hand shop find
Before National Museums Scotland acquired it, this astrolabe belonged to James H. Farr, who ran Wardie Garage on Ferry Road. In 1959, Farr attended a lecture on astrolabes by Robert Plenderleith, Keeper of the Royal Scottish Museum’s Technological Department. This prompted him to have his astrolabe dated. On learning quite how old his astrolabe was, Farr decided to give it to the National Collection. He told The Scotsman that he “bought the astrolabe about ten years ago in a second-hand shop in Edinburgh’s Lawnmarket”.
The astrolabe was originally displayed with horological collections at the Museum. Today, it sits in the
Earth in Space gallery
, which shows how stars and planets have been observed and used for timekeeping and navigation.
In 2024-25 it was loaned to the British Museum’s
Silk Roads exhibition.
There, it was displayed with other artefacts from Córdoba during the period of Umayyad rule, showing its cosmopolitan nature and cultural flourishing.
The National Museums Scotland Ibn al-Ṣaffār astrolabe with other objects from the British Museum’s Silk Roads exhibition in 2025.
Credit: Rebekah Higgett
Table of places and latitudes on the plates
The seven plates serve the following latitudes.
Latitude
Place name
Notes (including modern values)
0⁰
[Equator]
This marks the line of the horizon
14⁰ 30’
Sana‘a
Sanaa, Yemen – 15°20′54″N
17⁰ 30’
Saba’
Ancient Kingdom of Sheba, in what is now Yemen, perhaps marking its northmost expansion
21⁰ 40’
Mecca
Mecca, Saudi Arabia – 21°25′21″N
25⁰
Medinah
Medina, Saudi Arabia – 24°28′12″N
28⁰
Qulzum
Ancient city in Egypt, also known as Clysma; Suez – 29°57′16.6″N
30⁰
Cairo
Cairo, Egypt – 30°2′40″N
32⁰
Qayrawān
Kairouan, Tunisia – 35°40′38″N
34⁰ 20’
Surra-man-raa
Samarra, Iraq – 34°11′54″N
36⁰
Tanja
Tangier, Algeria – 35°46′36″N
38⁰ 30’
Cordoba
Córdoba, Spain – 37°53′24″N
40⁰
Toledo
Toledo, Spain – 39°51′24″N
42⁰
Saragossa
Zaragoza, Spain – 41°39′N
45⁰
Constantinople
Istanbul, Turkey – 41°00′49″N – the high value of 45⁰ was traditionally used
66⁰
[Ecliptic]
The ecliptic represents the apparent annual path of the Sun, its poles are +66⁰ and -66.5⁰, also seen as the ends of the inhabited world
These places are paired on the plates:
Sanaa and Mecca
Medina and Samarra
Kairouan and Córdoba
Zaragoza and Equator
Sheba and Cairo
Clysma and Tangier
Toledo and Constantinople.
The Ecliptic plate is engraved inside the mater.
Table of stars carried by the rete
The pointers on the 13th-century rete have been calculated as pointing to 21 bright stars:
11 in the northern celestial hemisphere
12 in the southern celestial hemisphere
Here they are listed by position on the rete, east to west.
The 13th-century rete
.
(
T.1959.62
)
Star name
On rete
Translation
Bayer designati
Algol
ghūl
Arabic: [head of] the ogre
beta Persei
Aldebaran
al-dabarān
Arabic: the follower
alpha Tauri
Capella
‘ayyūq
Arabic: the goat
Latin: little goat
alpha Aurigae
Rigel
rijl al-jawzā
Arabic: foot of al-Jawzā (Orion)
beta Orionis
Betelgeuse
yad al-jawzā
Arabic: hand of al-Jawzā (Orion)
alpha Orionis
Sirius
al-yamāniya
Greek: glowing or scorching
Arabic: Yemeni [i.e. to the south]
alpha Canis Majoris
Procyon
al-sha‘āmiya
Greek: before the dog (Sirius)
Arabic: Shamiya [i.e. to the north]
alpha Canis Minoris
Regulus
qalb al-asad
Latin: prince or little king
Arabic: heart of the lion
alpha Leonis
Spica
al-a‘zal
Latin: [the virgin’s] ear of grain
Arabic: the unarmed
alpha Virginia
Alkaid
banāt [nash]
Arabic: the leader of the daughters of the bier
eta Ursae Majoris
Arcturus
al-rāmih
Greek: guardian of the bear
Arabic: the lancer
alpha Bootis
Alphecca
al-fakka
Arabic: [the brightest of] the broken [ring of stars]
alpha Coronae Borealis
Antares
qalb al-‘aqrab
Greek: rival to Ares
Arabic: heart of the scorpion
alpha Scorpii
Rasalhague
r’as al-hawwā
Arabic: the head of the serpent collector
alpha Ophiuchi
Vega
al-wāki‘
Arabic: the falling [eagle]
alpha Lyrae
Altair
al-ta’ir
Arabic: the flying [eagle
alpha Aquilae
Deneb
ridf
Arabic: tail
Arabic: hindmost or follower
alpha Cygni
Deneb Algedi
dhanab al-jady
Arabic: the tail of the goat
delta Capricorni
Markab
mankib
Arabic: saddle (markab) or shoulder (mankab) [of the horse]
alpha Pegasi
Caph
kaff al-khadīb
Arabic: the stained hand
beta Cassiopeiae
Diphda
dhanab quaytus
Arabic: frog
Arabic: the [southern] tail of the Cetus (sea monster)
beta Ceti
The astrolabe is on display in the Earth in Space Gallery on Level 1 at the National Museum of Scotland.
Written by
Dr Rebekah Higgitt
Principal Curator of Science
r.higgitt@nms.ac.uk
You might also like
The Roaring Game: Scotland's curling stone island
Natural world
Written by Dr Bob Gooday
Did you know that all curling stones are quarried on a small, uninhabited island in the Firth of Clyde called Ailsa Craig?
Short read
What's in a firework? Minerals that bang
Natural world
Written by Emily Brown
So, you light a firework, you stand back and WHOOSH, off it shoots into the air. A few seconds wait and then BOOM, the firework explodes in a shower of coloured sparkles raining down from the sky. To get this sequence of events, you need…
Short read
Pocket watch from the shipwrecked Swan: a clockwork revelation
Science and technology
Written by Ella Paul & Dr Tacye Phillipson
Salvaged from a shipwreck, this pocket watch has lain hidden under water for over 300 years. Now, a high-tech process has uncovered the amazing hidden secrets of this rusty artefact.
Long read