COMET TALES

An upturned bowl we call the sky

Trapped under which we live and die.

I have always been fascinated by the stars, almost as much as the Moon, spending hours as a child watching the wheel of stars above me. It was only when I became able to read and understand, that I  began to fully appreciate what I was looking at. I had always wanted a telescope to be able to view them, but the simple plastic devices I got each Christmas would never be able to show me anything other than a blur. How amazing it must have been for civilisations in ancient time, when faced with eclipses, moon phases and the rare appearance of comets, when understanding of the heavens was even more distant.  Early maps of the sky and illustrations of the stars reveal some quite impressive depictions of celestial objects, such as the sky map shown above, from the book 'The Sky' by Jean Claude Pecker in 1960. It shows a representation of the four lower worlds with the constellation of the Pleiades above, Milky Way at lower left and even the crescent of Venus (upper left), which s normally invisible to the unaided eye. Somehow, the Chukchi tribe in Eastern Siberia were able to observe and record these sightings. 

Possibly one of the most famous records of a celestial event was the passing of Halley's Comet in April 1066, as depicted in the Bayeux Tapestry. The text 'Isti mirant stella' means, 'They wonder at the star' and its was later regarded as a bad omen fortelling the reign of Harold on the english throne. The comet had been regularly recorded since 240 BC, with sightings from Chinese records and the far east recording a 'bearded star'. It was not until 1705 that Edmund Halley, realised that the comet would make an appearance in 1758, as part of its 76 year orbit. 

There are many recordings of Halley's and other visible comets throughout history, such as this illustration from Peckers book from 1654.  The french miniature painting below shows another astronomical rarity, the fall of a meteor in the 11th century.
 

In Augsburg in Germany in the mid 1550's, a manuscript appeared detailing a whole series of strange events, including several comets reproduced in beautifully painted scenes. Along with scenes from the old Testament, 'The Augsburg Miracles' also included portential sightings such rains of blood, eclipses, earthquakes, strange births and may other events.

In modern times, the nature of comets is much better understood and their appearance can be calculated and predicted with great accuracy. Patrick Moore, the famous British astronomer in his 1972 book 'Challenge of the Stars' predicted the use of probes making close approach to a comet to study their make up. Only six years later, the first cometary probe ICE visited the comet  21P/Giacobini–Zinner and managed a distant observation of Halley's comet in the process. Over the next ten years several missions visited and photographed Halley's Comet as it approached Earth, discovering more and more about the mysterious visitor.

Nicholas Cheetham's photo exploration of the cosmos appeared in 2005, taking advantage of recent deep space and planetary mission data, to show beautiful full page photographs of the planetary bodies and comets such as WILD 2 and the Centaur comet 29P, as visualised by radio telescope.

My own experience of viewing such an occurrence came in March 1997, when comet Halle-Bopp was clearly visible in the heavens from the UK. Unfortunately for me, it was prior to the advent of viable and affordable digital photography, so I was unable to record my own sighting, but I can clearly recall seeing the beautiful dual tails, one faintly green, as the comet hovered on the horizon at dusk.

HALLE-BOPP COMET

11/OUNUAMUA

What prompted this particular post has been the recent arrival of a trio of extrasolar visitors, which began in 2017, when a high speed object was sighted, passing through the solar system on a trajectory which revealed that it had originated in deep space. Oumuamua, as it was known was a small roughly cylindrical object, approximately 1000-3000 metres long. As it approached the sun and began to accelerate, it did not develop the usual cometary coma and was designated as an 'interstellar object' rather than a comet. Naturally, speculation ran wild with suggestions that it was an alien spaceship, or artefact in the fashion of Arthur C. Clarkes 'Rama' device, from his novel 'Rendezvous with Rama'.

21/BORISOV

In 2019, the second interstellar visitor 21/Borisov was spotted, once more on a trajectory from beyond the solar system. Borisov did exhibit cometary activity and on close approach to the sun, developed a huge tail or coma, some 14 times the diameter of the Earth. Once more, speculation suggested another alien invasion, but Borisov continued on its way and subsequently left the system as quickly as it had arrived.

31/ATLAS

Most recently, the third mysterious visitor 31/Atlas was detected in July this year, coming closet to the sun on 25 October. With many telescopes and probes in place to investigate the comet, it was discovered that the comet contained an unusually high degree of carbon dioxide and water ice and was also found to be emitting cyanide gas. Following a hyperbolic trajectory and travelling almost 60 km per second, the comet has now passed close approach to the sun and is beginning it journey back into deep space. First photographed by the Hubble telescope in July, it has been imaged by two orbiting Mars probes and the Perseverance Rover. The James Webb Telescope is scheduled to make observations of it in December 2025, as it passes its perihelion.

Once more the internet and conspiracy theory community have seized upon the heavenly visitor as the topic of vigorous and imaginative speculation. Youtube is alive with clickbait videos purporting all kinds of nonsensical dramas, from mysterious shadowy figures being observed on it surface to intelligent messages being beamed from the object announcing the imminent arrival of mysterious beings, to NASA being responsible for a cover up and the armed forces being on high alert in case of attack or collision. In fact, Atlas will only come within 1,8 astronomical units of the Earth (almost twice the diameter of the Sun, so it does not pose any kind of a threat.

It would appear that in spite of mankind's development from a stone age civilisation, to a modern technocracy, there will always be those individuals who will fear the strange and otherworldly and assume that it portends disaster for us all.