For three centuries, this comet has been associated with British astronomer Edmond Halley (1656-1742), who was the first to calculate its periodic approach to Earth. The comet was named in his honor. However, authors of a new interdisciplinary study from Leiden University in the Netherlands claim that the true credit belongs to a monk named Aylmer—a Benedictine monk and chronicler from the 11th century in the English town of Malmesbury. According to the researchers, he understood the comet’s cycle 600 years before Halley.
Halley’s Comet is often referred to as the most famous comet in human history. This is primarily because it approaches Earth every 75-76 years, allowing many people to see it during their lifetime. Additionally, it is the only short-period comet that is easily visible to the naked eye. Its appearances have typically been linked to significant events and omens.
What Did the Scientists Discover?
The research was led by astrophysics professor Simon Portegies Zwart and historian Bob Zwart Lewis. It revealed that Aylmer connected two separate appearances of the same comet in 989 and 1066—long before Halley’s discovery in the 17th century.
Key historical information about this comes from William of Malmesbury, a 12th-century historian who documented English history after the Norman Conquest. In his chronicles, he described how an elderly monk named Aylmer (also known as Ethelmaer) observed a bright comet in 1066 and recognized it as the same object he had seen decades earlier in 989.
In those times, celestial phenomena were often interpreted as divine signs. Aylmer warned that the comet’s return foretold political upheaval.
Despite the significance of this recorded observation, historians and largely ignored it for a long time. However, they have now concluded that Aylmer’s discovery is, in fact, the earliest known detection of a periodic comet, predating Edmond Halley’s discovery by several centuries.
A fragment of the Bayeux tapestry, where people point to what we now know as Halley’s Comet.
The Latin text translates to ‘These (people) admire the star.’
Halley and the Famous Comet
Edmond Halley is one of the most distinguished British astronomers, earning lasting recognition for his work. He demonstrated that the bright comets observed in 1531, 1607, and 1682 were the same object. His prediction regarding the comet’s return in 1758 (after his death) was later confirmed. Thus, his scientific legacy was acknowledged, and the comet was named 1P/Halley.
Halley’s calculations were a breakthrough in astronomy. However, researchers now believe that the conceptual understanding of the comet’s periodicity existed long before this—despite the lack of mathematical tools to formalize it.
The comet’s appearance in 1066 became one of the most widely recorded astronomical events of the Middle Ages. Chinese astronomers observed it for over two months, noting its peak brightness on April 22, 1066. In Europe, it became visible in the British Isles on April 24, shortly before the Norman Conquest, as reported by Arkeonews.
The comet is also well-known for its depiction on the Bayeux tapestry, where it appears as a fearsome omen during the reign of King Harold II Godwinson. He ruled England for only nine months before his death at the Battle of Hastings.
British astronomer Edmond Halley
Should the Comet Be Renamed?
Given Aylmer’s discovery of the comet’s cycle 600 years earlier than previously thought, astronomers argue that the current name inaccurately reflects the history of its discovery. However, there is no discussion yet in the global scientific community about officially renaming the comet.
Nonetheless, there is hope that Aylmer from Malmesbury will eventually receive recognition as one of the first thinkers to perceive the long-term rhythms of the cosmos centuries before telescopes made such discoveries commonplace.
Photo: Unsplash
