Jun 18, 1178 CE: Monks May Witness the Moon 'Split in Two'

Jun 18, 1178 CE: Monks May Witness the Moon 'Split in Two'

On June 18, 1178, five monks in Canterbury, England, may have witnessed the formation of a crater on the Moon.


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Earth Science, Astronomy, Geology

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On June 18, 1178, five monks in Canterbury, England, believed they witnessed the formation of a crater on the Moon. The crater, marked by a bright ray system, is today known as the Giordano Bruno crater. The monks reported an impact in which “the upper horn [of the moon] split in two” and a “flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals and sparks.” In the near past, some astronomers said the monks’ account might actually be pretty right. A passing comet or asteroid probably collided with the Moon. The collision likely caused impact melts, or rocks melted by the shock of the powerful impact. This molten material could be the “flaming torch” the monks described.

This is disputed, however, as a possible cosmic coincidence. Scientists theorize the impact necessary to have created the large moon crater would have ejected so much debris that meteor storms would have occurred for days on Earth. Yet, the monks’ observations were not documented in other parts of the world.

The English monks likely saw a particularly spectacular meteor falling to Earth that just so happened to align with Giordano Bruno crater and Canterbury from their angle of observation. Seeing the meteor burn in Earth’s atmosphere as they looked up to see the crater, made the monks think they were seeing the crater’s creation. Furthermore, many modern astronomers, however, don’t think the crater is quite so young. Studies estimate the age of Giordano Bruno to be between over a million to 10 million years old—very young by cosmic standards, but nowhere near young enough for the English monks to witness!

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National Geographic Society
National Geographic Society
Last Updated

October 19, 2023

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