On 30 September this year the first human spacecraft ever to orbit a comet was deliberately crashed onto its surface in order to get the closest possible pictures of the enigmatic celestial body. This will end its mission that began when the vessel was launched over twelve years ago. During the past two years the European Space Agency’s Rosetta probe has been circling the comet millions of miles from Earth, making unprecedented close-range observations of Comet 67P/Churyumov–Gerasimenko (named after the two astronomers who discovered it).

Comet Churyumov–Gerasimenko in September 2014 as imaged by Rosetta. (ESA/Rosetta/NAVCAM /CC BY-SA 3.0 igo)

One of the spacecraft’s most significant accomplishments is to have taken readings of the comet’s makeup, determining that it contains some of the basic building blocks of life. Cometary impacts, it seems, may have helped start life on Earth. But comets, such as the focus of the Rosetta mission, have also posed threats to earthly life. 67P/Churyumov–Gerasimenko is around two and a half miles across; if it hit the Earth— which thankfully it won’t— it could put an end to civilization as we know it. A comet just 500 feet in diameter is believed to have caused the Tunguska event of 1908, when it exploded over a remote area of Siberia with the force of a fifteen megaton bomb, flattening 1000 square miles of forest. But the Tunguska comet was miniscule compared to one, estimated to have been around ten miles wide, which almost collided with our planet three and a half thousand years ago.

Trees knocked over by the Tunguska blast. (Public Domain)

Spectacular and Terrifying Ancient Comets

This comet was recorded by the Egyptians in the 22nd year of the reign of the pharaoh Tuthmosis III, who described it as a brilliant disk much larger than the full moon, adding that it was “a marvel never before known since that foundation of this land [Egypt].” Chinese astronomers, who meticulously recorded celestial occurrences for astrological purposes, also noted the breathtaking event. The ancient Mawangdui Silk Almanac, preserved in the Hunan Provincial Museum in Changsh, depicts the comet as one of the largest ever observed. Not only did it fill a large part of the sky, it had an astonishing ten tails. (The biggest comet observed since the birth of modern astronomy, De Cheseaux’s Comet of 1744, had only seven.)

The Egyptian record is found in a manuscript now in the Vatican Library, called the Tulli Papyrus, and a number of writers have cited it as evidence for an ancient UFO sighting, leading some scholars to question its authenticity. However, it would seem to have concerned a genuine event. The 22^nd year of Tuthmosis III’s reign is thought to have been around 1486 BC, which is precisely the year (by our modern calendar) that the Chinese observed the ten-tailed comet.

Impression of the spectacular ten-tailed comet recorded by the Ancient Egyptians in 1486 BC.  (Illustration by Graham Phillips)

The comet must have passed terrifyingly close to our planet. Indeed, the ancient comet’s appearance was so spectacular that it seems to have had a profound influence on religions throughout the world. It seems that this unprecedented celestial phenomenon was taken to be the appearance of a new god: at this precise time, contemporary civilizations across the globe all began to worship a new deity depicted as a winged disk hanging in the sky. Examples include the Hittite god Kumarbis, the Assyria god Antum, the Mitannian god Ir, and the Persian god Ahura Mazda.

The Assyrian winged disk. One of the many similar glyphs that represented deities that appeared throughout the world after the comet’s appearance in 1486 BC. (Public Domain)

In China, a new divinity called Lao-Tien-Yeh – “The Great God” – appears at this time during the Sang dynasty and was represented by a circle with a series of straight lines radiating in a fan shape beneath and to the side of it, which looks remarkably similar to a depiction of a comet.

The symbol for the god Lao-Tien-Yeh glyph that first appeared in China during the early fifteenth century BC. (Photography by Graham Phillips)

Fascinatingly, this glyph is almost identical to the symbol for a new god that appeared in Egypt during the reign of Tuthmosis III. Called the Aten, it was represented by a circle with a fan-shaped series of lines radiating from it, just like the symbol for Lao-Tien-Yeh. Egyptologists have long assumed that the Aten glyph represented the sun, which no doubt it did when the pharaoh Akhenaten made Aten worship the state religion in the mid 1300s BC, but when it first appeared in the capital of Thebes over a century earlier it is accompanied by no inscriptions specifically associating it with a solar deity.

The Egyptian Aten symbol that may originally have depicted the magnificent comet of 1486 BC. (Public domain)

But the sudden appearance of new religions was not the only social upheaval to accompany the comet’s close encounter with Earth. Throughout the world, there was a simultaneous and unprecedented period of violence. Egypt embarked on a vicious military campaign, conquering what are now Israel, Lebanon, and Libya; the Hittites of Turkey struck out at their neighbors in the eastern Mediterranean; in Syria, the Mitanni kingdom attacked the Assyrians of Iraq; the Kassites of northern Iran invaded Babylonia in southern Iraq; the Yaz people of Armenia ferociously attacked everyone around them; and the Harappan civilization of north-west India was wiped out by marauding tribes from Afghanistan. And all this followed a period of relative peace throughout the world that had lasted for generations. Experts generally believe that the period of intense warfare and social unrest around the world was due to a short term climate change that saw global temperatures drop. Resultant crop failures meant the kind of scarce resources that invariably lead to conflict. The question, however, is what caused the bad weather that lasted for a decade or so?

Threats to Life and  Civilization

In 1985 astronomer Carl Sagan identified the comet of 1486 BC as Comet 12P/Pons-Brooks, suggesting that a fragment of it had broken off and impacted with the Earth, the resultant explosion throwing debris high into the atmosphere and impeding the sun’s rays for many years, causing global temperatures to fall. But this may not have been the only effect of the cometary impact. At the International Conference on Catastrophic Events and Mass Extinctions held in Vienna in July 2000, scientists gathered to discuss possible threats to life on Earth posed by asteroid and comet impacts.

Interestingly, beside the obvious calamities such impacts would cause, such as firestorms, nuclear winters, and tsunamis, attention was drawn to various harmful chemicals that some comets contain. One of these is the amino acid vasopressin that can cause violent and aggressive behavior in humans. It is not at present known if 12P/Pons-Brooks contains vasopressin, but it if it does then the substance entering the atmosphere to contaminate the food chain could in part have been responsible for the unprecedented period warfare that griped the planet in the early 1400s BC.

Comet 17P/Holmes and its blue ionized tail. Representational image. (CC BY-SA 3.0)

Coincidentally, just as the Rosetta mission comes to an end, astronomers have determined that a fragment of 12P/Pons-Brooks—the comet of 1486 BC— is heading for its closest approach to Earth on 11 February next year. The comet has broken into several pieces after a close pass with Jupiter, one of them being what is now designated as Comet 45P/Honda-Mrkos-Pajdusakova, first identified in 1948. It is around a mile wide, but luckily it won’t hit the Earth. However, it is possible that the Earth’s orbit could take us through the comet’s trail. Whether or not that would have an effect on out atmosphere remains to be seen.  But even if it passes safely by, the main comet itself, still well over five miles wide, is due to return to the inner solar system in 2024, but exactly how close it will come to Earth is at present unknown. Let’s hope for the best. The last thing the world needs now is elevated levels of aggression.

Source: Ancient Origins