Hartung recognized that the probability was “extremely small,” since there was only one chance in a thousand that such a great impact would have occurred throughout the recorded history of mankind. Studying the high-resolution images taken in the 1970s by t he Apollo missions, Hartung could see that the long, bright radial marks produced during the formation of the crater had not yet been erased by the lunar dust spread by micrometeorites, indicating that its origin was recent and, therefore, could correspond to the phenomenon seen in 1178. In the region where Gervasio had located the phenomenon, a 22-kilometre crater is located, named after the Italian philosopher and astronomer Giordano Bruno. Hartung favoured the possibility that the origin was an enormous impact on the lunar surface. Interactive timeline: Histories of the Moon This led him to publish a study that seemed to solve the historical enigma with an explanation as fabulous as the spectacle that Gervasio related. The chronicler’s assertion that the witnesses had sworn the truth of the story on their honour aroused Hartung’s interest.

Hartung, geophysicist at the State University of New York at Stony Brook, rediscovered it in 1976. What did these men observe? The narrative of Gervasio of Canterbury remained almost forgotten for centuries until Jack B. “From the midpoint of the division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals and sparks,” wrote Gervasio, adding that the Moon “ writhed, as it were in anxiety” and that “it throbbed like a wounded snake.” After all this, the celestial body turned blackish. According to the monk Gervasio, chronicler of the Abbey of Christ Church in Canterbury, the upper horn of the crescent Moon was split in two. One hour after sunset on 18 June 1178, at least five men in southern England reported having witnessed an unusual phenomenon in the sky.

What happend to the moon