The Moon Will Appear Split Again but With It
One hour after sunset on xviii June 1178, at least five men in southern England reported having witnessed anunusual phenomenon in the sky. 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. "From the midpoint of the division a flaming torch sprang upwards, 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.
What did these men observe?The narrative of Gervasio of Canterbury remained almost forgotten for centuries until Jack B. Hartung, geophysicist at the State Academy of New York at Stony Brook, rediscovered information technology in 1976. The chronicler's exclamation that the witnesses had sworn the truth of the story on their honour aroused Hartung's involvement. This led him to publish a study that seemed tosolve the historical enigma with an explanation every bit fabled as the spectacle that Gervasio related.
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Hartung favoured the possibility that the origin was anenormous touch on the lunar surface. In the region where Gervasio had located the phenomenon, a 22-kilometre crater is located, named after the Italian philosopher and astronomer Giordano Bruno. Studying the high-resolution images taken in the 1970s by the Apollo missions, Hartung could see that the long, bright radial marks produced during the germination of the craterhad not nevertheless 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.
An enormous impact or a meteorite
Hartung recognized that the probability was "extremely small," since at that place was onlyi take chances in a thousand that such a great impact would take occurred throughout the recorded history of mankind. Withal, his theory received an accolade two years later on from astronomers Odile Calame and John Derral Mulholland, who analysed new images collected by the Soviet probe Luna 24 to conclude that, although their study could not prove Hartung's interpretation, at least the data were "consistent with the hypothesis."
However, this does not imply that Hartung's theory was widely accepted. Equally early on as 1977, meteorite specialists Harvey Harlow Nininger and Glenn I. Huss questioned the hypothesis, challenge that the formation of Giordano Bruno'southward craterwould not take caused the phenomena reported by the monk. Instead, the two experts proposed some other more plausible explanation that Hartung himself had mentioned in his report: the entrance of a meteorite into World's atmosphere that coincidentally remained in the Moon's visual line for observers from southern England.
A crater over i million years old
In fact, many experts have been sceptical, since the youth of the crater must exist understood in geological time. According to the astronomer Tomokatsu Morota, who in 2009 calculated an age for Giordano Bruno of betwixt ane and ten one thousand thousand years, the density of pocket-sized craters formed on the ejected fabric leads to a conclusion: "there is no possibility that information technology was formed 800 years ago." The cosmogeologist Jörg Fritz, who in 2012 estimated the age of the crater at more than one million years, adds yet another gene: "Nosotros can exclude that the crater formed 800 years ago as nosotros would still be exposed to a rain of lunar rocks from that rare and big issue," he tells OpenMind. Also and due to the impact, "parts of the craterwould nonetheless show elevated temperatures that are, however, not observed by lunar orbiter missions."
In 2001, then-graduate student Paul Withers of the Academy of Arizona put numbers on the lunar meteor shower that would take fallen on Globe if Giordano Bruno's crater had been created in 1178. In his study, the astronomer detailed thatthe crater was created by the impact of an asteroid between one and three kilometres, which co-ordinate to previous estimates would have released 10 meg tons of lunar material in the management of Earth.
Withers estimated that this should accept triggered anintense meteor shower during the week after the collision, similar to that of the Leonids in 1966, which produced upward to 100,000 shooting stars per hour. "It would have been a spectacular sight!" Withers said afterward the publication of his study. "Everyone effectually the world would have had the opportunity to see thebest fireworks show in history."
¿A real enigma or a fantasy?
No chronicle of the time recorded such phenomenon, which led Withers to conclude that the virtually plausible explanation is the one advocated by Nininger and Huss. "I recollect [the witnesses] happened to be at the right identify at the right fourth dimension to expect up in the heaven and encounter a meteor that wasdirectly in front of the moon, coming straight towards them," Withers said. "And it was a pretty spectacular meteor that burst into flames in the Earth's atmosphere — fizzling, bubbles, and spluttering. If yous were in the right i-to-2 kilometre patch on Globe'south surface, you'd get the perfect geometry."
For Withers, this would explain whyonly a few people witnessed the alleged moon bibelot, which was, in his view, nothing of the sort. Unlike the asteroid whose impact more than one million years ago scarred the lunar surface with Giordano Bruno's crater, the meteorite that could have caused the optical illusion of 1178 would have been of a small-scale enough size to have burned upward in the Earth's temper without major consequences.
And then, enigma solved? Perhaps there never even was an enigma: in his study, Withers outlined another fifty-fifty greater problem, which is that on eighteen June 1178 the crescent Moon was non yet visible from Canterbury. The astronomer suggested that perhaps the date was incorrect, but in 2002 the historian of astronomy Peter Nockolds went farther by suggesting that Gervasio's story could be a complete fantasy: the monk, Nockolds argued,had the addiction of associating foreign celestial apparitions to Christian victories in the Crusades. The vision of the half moon breaking in two could merely be a propagandistic symbology near the triumph of the Crusaders against Islam. We will probably never know the truth.
Javier Yanes
@yanes68
Source: https://www.bbvaopenmind.com/en/science/physics/the-mystery-of-the-moon-divided/
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