That's exactly what five monks claimed happened on the evening of June 18, 1178, in Canterbury, England. Their account, recorded by the chronicler Gervase of Canterbury, is one of the most bizarre and debated astronomical observations in history.
The Monks' TestimonyAccording to the chronicles, about an hour after sunset, five witnesses watched in horror as the upper horn of the new crescent Moon "suddenly split in two."
From that division, they reported, "a flaming torch sprang up, spewing out fire, hot coals and sparks." The body of the Moon below writhed and "throbbed like a wounded snake" before returning to normal. The phenomenon repeated a dozen times or more.
For centuries, this account was treated as curious folklore - until 1976, when geologist Jack Hartung dropped a bombshell.
The "Solved" Mystery
Hartung proposed that the monks had witnessed something unprecedented in human history: the formation of a lunar crater.
The crater in question? Giordano Bruno, a 22-kilometer-wide impact scar on the Moon's northeastern limb. It's surrounded by bright rays of ejecta that haven't been darkened by space erosion - a clear sign of youth. Hartung argued that its location and apparent age perfectly matched the monks' description.
For a quarter-century, this became the accepted explanation. Textbooks and documentaries cited the "first and only eyewitness account of a lunar impact."
But science kept digging.
The Problem: Where Were the Fireworks?
Enter Paul Withers, a University of Arizona graduate student with a calculator and a skeptical eye .
In 2001, Withers did the math. An impact large enough to create a 22-kilometer crater would have launched 10 million tons of lunar ejecta into space.
That debris wouldn't just disappear. A significant chunk would have rained down on Earth's atmosphere in the following week, creating a meteor storm of epic proportions.
How epic? Withers calculated 50,000 meteors per hour - comparable to the peak of the 1966 Leonids storm. These wouldn't be faint streaks. They'd be magnitude 1 or 2, visible to everyone on the planet.
"It would have been a spectacular sight to see!" Withers said. "Everyone around the world would have had the opportunity to see the best fireworks show in history".
Yet Withers searched every historical archive he could find - European, Chinese, Arabic, Japanese, Korean. Nothing. No accounts of a week-long meteor storm anywhere in the world
The Smoking Gun: The Crater's True Age
Then came the knockout punch.
In 2008, Japan's SELENE lunar orbiter took high-resolution images of Giordano Bruno. Scientists counted the smaller craters within it - a standard technique for determining age.
The result? 4 million years old, plus or minus 3 million.
Not 845 years. Millions of years.
The crater the monks supposedly saw form had existed long before humans ever walked the Earth.
So What Did They Actually See?
If not a lunar impact, what caused five monks to swear on their honor that they saw the Moon split and writhe?
The leading explanation is almost as strange - and far more intimate.
Withers and others believe the monks were simply in the perfect place at the perfect time to witness a meteor coming straight toward them, perfectly aligned with the Moon .
Imagine a large meteor entering Earth's atmosphere directly along your line of sight to the lunar surface. As it burns up, fizzling and spluttering, it would appear projected against the Moon - creating the illusion that the Moon itself was erupting.
"If you were in the right one-to-two kilometer patch on Earth's surface, you'd get the perfect geometry," Withers explained . That's why only five people reported it. Everyone else just saw a meteor streaking across the sky .