Dragons and winged serpents appear in myths and legends told by people all over the world. Could a comet impact that happened at the end of the ice age, some 12.900 years ago, have been the inspiration for all those stories?
The onset of the Younger Dryas, a geologic period that lasted from 12.900 to 11.700 years ago, is one of the most well-known examples of abrupt climate change. About 15.000 years ago, the Earth's climate began to shift from a cold glacial world to a warmer interglacial state. Partway through this transition, temperatures in the Northern Hemisphere suddenly returned to near-glacial conditions.
This near glacial period of about 1.200 years is called the Younger Dryas, named after Dryas Octopetala, a small flower that grows in cold, artic conditions and became common in Europe during this time. The end of the Younger Dryas, about 11.700 years ago, was particularly abrupt. In Greenland, temperatures rose 10°C in just a few years.
The Younger Dryas return to a cold, glacial climate was first considered to be a regional event restricted to Europe, but later studies showed that it happened worldwide. Besides the Younger Dryas cooling, several other shorter cooling/warming events, now known as Dansgaard-Oerscher events, have been revealed by data from ice cores that were drilled in Antarctica and Greenland.
The GRIP (Greenland Ice Core Project) ice core has been especially important because the age of the ice at various levels in the core has been determined by the counting down of annual layers in the ice, giving a very accurate chronolgoy. Oxygen isotope data from the GISP2 Greenland ice core, used to determine temperature fluctuations, suggest that Greenland was more than 10°C colder during the Younger Dryas and that the sudden warming of 10° ±4°C that ended the Younger Dryas occurred in just a few years.
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It is now generally accepted that the Younger Dryas was caused by a comet impact that hit the Laurentide Ice Sheet, a kilometers thick sheet of ice that 12.900 years ago covered most of North America. This must have been an enormous global disaster. When the celestial object smashed into earth, in an estimated number of 7 fragments, an enormous heat was released and large amounts of dust and ashes were blown into the atmosphere, eclipsing the Sun for years.
As a result of the energy released by the impacts parts of the Laurentide Ice Sheet melted which may have caused huge tidal waves. The sudden influx of fresh water from North America caused a shutdown of the North Atlantic 'Conveyor', which circulates warm tropical waters northward. This process, which formed the Great Lakes, may have contributed to the sudden drop in temperature.
The Younger Dryas Boundary, sometimes referred to as the 'Black Mat', has long been recognized in sediments around the world as marking the beginning of the Younger Dryas. It also corresponds to the sudden disappearance of the North American Clovis people and many large animals including mammoths, mastodons, american camel, dire wolf, and giant ground sloth in North America.
The cataclysmic event may well have formed the basis for the many myths and legends about a winged serpent or fire-breathing dragon. Snakes had already been in use as religious and archetypical symbols long before, but the appearance of a havoc wreaking serpent in the sky might have been the reason to add the image of a flying dragon to that.
A comet approaching earth under an angle would be stretched out into a long string of fiery fragments and debris due to Earth's gravitational pull. This happens because, unlike asteroids, comets are mainly composed of dust and ice. To the people at that time it might have looked like a big fire-spitting serpent flying through the sky. Other impact events, like the one that according to some theories caused the Great Flood around 2,700 BC, may also have served as an inspiration for this image.
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In 'The Vala's Prophecy' from the Edda, a collection of ancient Norse myths and sagas, we seem to catch traditional glimpses of a terrible catastrophe: "Hrym steers from the east, the waters rise, the mundane snake is coiled in the rage of the fire-giant. The worm beats the water, and the eagle screams: the pale of beak tears carcases... The stony hills are dashed together, the giantesses totter, men tread the path of Hel, and heaven is cloven...The sun darkens, earth in ocean sinks, fall from heaven the bright stars, fire's breath assails the all-nourishing tree, towering fire plays against heaven itself".
The image of a dragon is usually explained by pointing to the skeletons of dinosaurs that were found in earlier times as well. The ancient Greeks, for example, were well aware of their existence. However, this doen't explain why dragons fly through the sky spitting fire and smoke. Of course all this remains just a hypothesis but in any case, even today the arrival of a comet in the sky is considered to be a bad omen.
Image on top: JPL/NASA