Anglo Saxon Astronomy

Tuesday 15th June, 2021


Our speaker (on Zoom) was Martin Lunn who told us about "Anglo-Saxon Astronomy". He is the former curator of astronomy at the Museum of York and is a leading authority on not only the renowned telescope maker Thomas Cooke of York but also the 18th Century deaf astronomer John Goodricke who also lived in York. Currently, in addition to giving talks he is featured on BBC Radio York and writes for a regional newspaper.

He began by saying that the Anglo-Saxon period covered over 600 years from roughly 410 to 1066 CE. The term "Anglo-Saxon" is actually relatively new and refers to the people who came form the German regions of Angeln and Saxony. They travelled to Britain after the Roman withdrew in the beginning of the 5th Century so that the Roman armies could defend their Empire, and this power vacuum also allowed Jutes and Frisians from Denmark to settle.

Most of our information about science and astronomy in this period comes from a series of historical records collectively known as the Anglo-Saxon Chronicle. These were written in various monasteries during the period from 892 to 1154 CE and document the history of England and Europe. Interestingly, the accounts are written in what we now term Old English when at that time the clergy would normally have used Latin, and also the dating of events is from the birth of Christ. There are fewer records from the years 850 to 1,000 CE as English society was disrupted due to the Viking raids, and the records end when the Normans invade in 1066 CE.

There are 36 astronomical events recorded in the Chronicle: 11 comets, 9 lunar eclipses, 8 aurorae, 7 solar eclipses and a single meteor shower. Further information about astronomical knowledge at that time comes from other treatises written by monks such as the Venerable Bede. Much of their work was devoted to the calendar and timekeeping, being used to calculate the date of Easter, as it is a moveable feast based on the lunar cycle. However, they also understood much more, such as the idea that Mercury and Venus orbited the Sun. They calculated that a solar year was 365 days and 6 hours, and every 4 years added an extra day, and also worked out the Moon's orbital period to be 27 days and 8 hours.

It is also evident that their study of the night sky helped with sea trade, for their name for the star that marked the North point of our compasses (Polaris) was "scipsteorra", which means "ship star". Other practical applications, such as the "breathings of the Moon" (a quote from Saint Bede) allowed the monasteries to make money when sailors paid for information about the tides.

Although the Anglo-Saxons were the dominant culture at this time, they were also, no doubt, influenced by the surrounding cultures of the Celts, the Greeks and later the Vikings. Each of these had their own mythology that was reflected in the night sky. For instance, the Vikings thought that the plane of our galaxy, the Milky Way, was actually the saliva from wolves. They also saw the winter constellation that we know as Orion the Hunter was a mother earth figure known as Goddess Frigg, and Orion's belt of three stars and his sword was instead a spindle to spin linen to make cloth.