‘Astronomical’ achievements: How Arabs left a lasting imprint in the sky

This led to subsequent scientific discussions, where the journal Isis published an article by Victor Roberts entitled, "The Solar and Lunar Theory of Ibn Al-Shatir: A Pre-Copernican Copernican Model."

Sources of European scientific discoveries revealed

In his book Islamic Science and the Making of the European Renaissance, George Saliba tells the story of this discovery, which greatly confused the academic community and raised the broad question of how European Renaissance sciences developed and what their sources were.

The Europeans thought Renaissance sciences were purely made in Europe, i.e. they were almost created from virtually nothing.

Those whose horizons were slightly broader, and looked beyond the European world's boundaries, assumed that Renaissance sciences were inspired by the ancient Greeks. No one assumed that these sciences had derived anything from Islamic Arab sources.

Mainstream opinion in these circles assumed European hostility toward Islamic Arab sciences; no one expected such a fruitful scientific convergence to occur.

The discovery of the direct link between Copernicus' work and the Arab theories about the movements of celestial bodies, which appeared in the Islamic world some two or three centuries earlier, was shocking and hasn't yet been understood by secondary sources that tell the history of science in general, according to Saliba.

Therefore, we see a small number of researchers who recognise the existence of this link and appreciate its meaning.

This scientific discovery opened the door for expansive research of Arabic manuscripts that catalogued celestial bodies and orbits.

Researchers were surprised to find that Arab astronomy provided the scientific material that led to the development of modern astronomy.

This meant that every scientific advancement in the study of astronomy and space is in no way separated from the theories and equations of Ibn Al-Haytham, Ibn Al-Shatir, Al-Battani, Abu Al-Rayhan Al-Biruni, Nasir Al-Din Al-Tusi, Muayyad Al-Din al-Urdi, and many others.

Islamic Age of Enlightment

The Islamic world was the centre of astronomy in the world from the 2nd to the 10th centuries AH. It assimilated, translated and critiqued previous sciences from Greece and India.

This led to the development of new theories and mathematical equations; the invention of astronomical tools; the construction of major astronomical observatories; the discovery of orbits of planets, stars, and satellites; the measurement of days; the study of the Earth's sphericity; the development of maps; the creation of models of the globe and astrolabes; and the observation of stars and the assignment of names to them.

Today we can hardly find any astronomical tool, observatory, or mathematical equation without finding a deep fingerprint of Arab heritage. In general, it was a major scientific revolution that led to the establishment of the modern scientific renaissance in astronomy.

Astronomical achievements

In his book, 'In Our Arab Islamic Heritage', Toufic Al-Tawil tells us about the great advances made by Arab scientists in the field of astronomy.

They pioneered the invention of machines that would extend the capacity of the senses to perceive, and the invention of devices that would help to transform the results of their studies into numerical quantities characterised by extreme precision.

The first astronomical observatory, which was established in Alexandria in the 3rd century, was the only one in the world until the Arabs established observatories in Baghdad, Cairo, Damascus, the cities of Andalusia, Maragheh, Samarkand, and others. 

The Abbasid caliph Harun al-Rashid brought together the most famous Arab astronomers of his time and asked them to make new instruments to observe celestial bodies; they did and used the instruments in many of their observations.

Thanks to these tools, the Arabs corrected many errors in Greek astronomy, which had been common and taken for granted. They also came up with troves of new facts.

One of their greatest achievements was calculating the exact number of days per year.

Abu Abdullah Mohammed bin Jaber bin Sinan Al-Battani, counted the number at 365 days, five hours, 46 minutes, and 24 seconds, which is only slightly different from our exact account today, by two minutes and 23 seconds.

This demonstrates surprising accuracy and unparalleled ingenuity, taking into account the tools and techniques that we have today compared to theirs.

The Arabs also predicted solar and lunar eclipses with impressive accuracy and proved the Earth's sphericity and rotation.

In the 3rd century, Abbasid astronomers were able to measure the deviation of the Earth's axis: Al-Battani calculated the inclination of the zodiac's orbit to the day's average orbit at 23 degrees and 35 minutes (35'.23°). Recent astronomical studies have shown that he was very right save to one minute.

Harun al-Rashid wanted to verify the accuracy of the Ptolemaic geography's measurement of the Earth's circumference. He tasked a group of Arab astronomers to do so.

Some of them walked between Wasit and Raqqa – a village west of the Euphrates opposite Raqqa – and Palmyra. There they measured the degree of the greatest circle passing through the surface of the Earth's sphere, which was 57 miles.

They observed the position of the sun from Palmyra and Sinjar at the same time and reached an estimate of the circumference of the Earth at 41,248km, which is a bit larger compared to modern astronomical calculations.

This is why the Italian orientalist Carlo A. Nallino, in his book Arabian Astronomy: Its History during the Medieval Times, says: "The Arabs measurement of the Earth's circumference is the first real measurement conducted directly with all the long time, difficulty, and hardship required by the task, and with the participation of a group of astronomers and workers; we must count that measurement as one of the famous glorious scientific works of the Arabs."

Evidence of Arab ingenuity and excellence in astronomy is so abundant that it's difficult to count them; a number of historians and Orientalists believe that the greatest science of Islamic civilisation is astronomy. 

Yet this ancient heritage is still a wide sea that needs further discovery and research into its treasures and secrets.

This evidence gives us a glimpse of the scientific accuracy reached by those brilliant scientists with their tools and observations at that time. It expresses the most impressive images of dedication and devotion to the service of science and the advancement of human civilisation.

Space is abundant with the achievements of Arab scientists who made history and greatly advanced the science of astronomy.

We recall these great Arab achievements on the heels of a historic moment for Saudi Arabia which launched a scientific mission into space last week, sending the first Arab and Muslim woman into space. Rayyanah Barnawi, alongside Ali Al-Qarni — both Saudi nationals — made the trip to the International Space Station last week.

Saudi Arabia is the first Arab country, so far, to send three astronauts to space, having sent Prince Sultan bin Salman Al Saud in the 1980s.