Throbbed like a Wounded Snake

06 18 moonOn the 18th June 1178, in Canterbury, just after sunset, five monks were gazing up at the moon when something very unusual happened. No one knows what is was, but it looked like this…

“There was a bright new moon, and as usual in that phase, its horns were tilted toward the east; and suddenly the upper horn split in two. From the midpoint of this division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals, and sparks. Meanwhile the body of the moon which was below writhed, as it were, in anxiety, and, to put it in the words of those who reported it to me and saw it with their own eyes, the moon throbbed like a wounded snake. Afterwards it resumed its proper state. This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal. Then after these transformations the moon from horn to horn, that is along its whole length, took on a blackish appearance.”

We know this because it was written down by a chronicler called Gervase of Canterbury. He had the story directly from the eyewitnesses. It must have looked as though the world was about to end. They must have been terrified. Sadly, as it happened more than eight hundred years ago, we can only guess at what really happened. There are a couple of theories though.

In 1978, a geologist called Jack B Hartung published an article suggesting that what the monks had witnessed was a comet or asteroid colliding with the Moon forming the 14 mile wide crater on the far side of the moon, now called the Giordano Bruno Crater. I mentioned Bruno only a few of days ago. A man whose entire body of work was banned by the Catholic Church between 1600 and 1966. Yet in 1961, he had a crater named after him. Which just goes to show, you can’t please all of the people all of the time.

06 18 giordano bruno craterThe crater was certainly formed relatively recently as the impact marks are still visible on the lunar surface. But in geological terms, recently means any time in the last 350 million years. While 18th June 1178 is certainly a date within the last 350 million years, it is odd that no other historical records anywhere have anything to say about it at all.

More recently, in 2001, a graduate student at the University of Arizona, called Paul Withers, did a bit more research. He calculated that a crater of that size would have been caused by an object that was somewhere between a half and two miles across. It would have thrown around ten million tons of debris into the Earth’s atmosphere. It would have caused a week long meteorite storm. There would have been maybe 50,000 meteorites an hour raining down all over the planet. Yet a search of historical records from Europe, the Middle East, China and Korea finds no mention of it.

It is much more likely that what the monks saw was an exploding meteorite, directly between them and the moon, hurtling straight towards them. Still pretty exciting, but with less catastrophic potential. Such an event would only be visible if you were in a very specific spot, or at least within a mile or so. This would explain why only five people saw it.

I love historical descriptions of events that are completely mystifying to us. They paint such a fascinating picture, yet explain nothing. I enjoy the gulfs of understanding between us and our predecessors as much as the similarities. If you’re in the mood for more unexplained phenomena from history, there are more here.