The Comets: 
Ghosts of Fiction....Portrayers of Fact....Soothsayers of Fantasy
an explanation by
P. Clay Sherrod
Brian M. Sherrod
Arkansas Sky Observatory
Breaking the fears and myths of comets in history.....
Every generation realizes its fair share of fear, fantasy and even tragedy from the sudden appearance of a bright comet....indeed we are well reminded of the horrendous events only a few short years ago with the passing of the beautiful comet Hale Bopp.
In 1909 and 1910 the streets of major cities across the world - London, New York, San Francisco, Tokyo, Moscow and Prague to mention only a few - were filled with vendors peddling potions and "anti-comet-sickness pills" to ward off the effects of the approaching pass of famed Halley's Comet in 1910.
( photo..... story ).  In earlier "civilized times" villages and settlements across the Earth would see their residents stand in fear and awe as a bright comet loomed over the eastern or western skies....these predictors of great pestilence, plague, misfortune and even more common problems of hens laying strange eggs, the miscarriage of pregnant cattle and the deaths of rulers or Princes throughout the world.
It was not long, however, before mankind realized that with every comet seen in the sky, somewhere....some prince will indeed die every day, some cattle will be still-born and some disease will take its toll on people across the globe.
It was not until 1577 that careful observations of comets began ( ) by the Danish astronomer Tycho a time when much of mankind still believed that the entire universe, including our own sun, revolved around the Earth, still unconvinced by the works of Galileo and later Copernicus to lead us into other more meaningful directions.  Years later, in 1607, Johannes Kepler described the motions of the comet of that year - what would be later known as Halley's Comet - in such detail as to suggest that all such objects are merely "visitors" which pass through our system of planets in a straight path and never will be seen again, exiting out into deep realms of space.
But in 1705 Edmund Halley - using the earlier studies by Issac Newton on the laws of gravitational influence and the motions of planets by Kepler - published his study of 24 comet's pathways through the skies, including that one observed by Kepler...low and behold, he suggested that they might ALL be the same object, moving in a closed orbit that would take it far away from the sun (aphelion), only to see it return in a number of years to pass very close to the sun (perihelion) at which time it would be very bright and perhaps even spectacular as were the comets observed by Brahe and Kepler.
The same object....and he predicted it would return every 76 years and again in 1758, which it did and has become known in his honor ever since as "Halley's Comet."  The superstitions, myths and fears of the mystic comets were about to erode.  These were merely other bodies of the solar system, traveling about the sun just as do the earth, planets and their moons ( )
Comet Superstitions....,
As with the comets of today, mankind has had an affinity - a strangely attractive likening and affliction - to the appearance and "intents" of comets when they appear.  "What do they mean?"  "Why suddenly has one appeared?"  "Why are there so many wars right now, while this bright comet is coming?"
Coincidence....just as the hen laying a peculiar-shaped egg, or the death of Prince Pogo on the eve of the brightest night of our celestial visitor.
The aforementioned Comet Hale Bopp (1995 O1 as it is known to astronomers) brought tragedy to many men women and children who were convinced of the comet curse...only this time they were convinced that an alien invasion was imminent as they followed in the cloak and mask of the comet's tail, waiting to attack and overrun our planet as the comet swept never happened, but those unfortunate number never lived to realize their misunderstanding and misfortune.
The comet was indeed a bright and beautiful spectacle of the sky ( ) but was unaccompanied by aliens, much less hostile ones.
Indeed, Comet Halley of 1910 was purported to be bringing noxious and poisonous gases as it was revealed by astronomers the year before that the earth was going to pass "right through the tail" of the comet in 1910.....only months after it was discovered that one of the trace molecules in comet tails was none other than cyanide.  People invested heavily in the sickness pills, moved their belongings underground, sold their possessions and more.  Other comets have led the misled to seeking high ground to avoid predicted catastrophic flooding, massive worldwide wildfires, earthquakes, impending revolutions and Armageddon.
And...all have been proven wrong.  Two quick points of reason:  comets are cold to the touch if one could indeed "touch it", and the only known modern comet impact to the earth might have been an explosion in 1908, now known as the "Tunguska Event" ( ) during which a nuclear-like explosion rocked an uninhabited section of remote Siberia, from what is thought by many to have been a fragment of a passing comet that vaporized just above ground level of the Earth.
The world has never ended from the passing of a comet in early history...or if it did, no one told its inhabitants; likewise, no one became ill or died from passing through the tail of Halley's Comet in 1910...there were no aliens that came to be among us in 1997 from Hale Bopp....
...and there will never be such things ever related to comets.  The comets (or "cometes" from the Latin for "long-haired") are merely very small bodies orbiting our sun which begin to glow and fluoresce when they reach about the distance as the orbit of the planet Mars, some 60 millions miles away.  These bodies are a natural part of the solar system, the Milky Way galaxy that we live in, and the grand Universe that holds all of this together.
As one philosopher noted in early comet-fearing times: 
 "Comets, according to the [Catholic] church are supposed to be the frowning face of God
....but they cannot be, because, obviously, we all KNOW that GOD does NOT have a tail...."
Common comet misconceptions.....
As with the bright comet of tonight's skies, there are always some very common threads and misconceptions about these celestial visitors.
1) Comets are huge, planet-sized objects - false; the largest comet is nothing more than a huge conglomeration of rocky chunks and frozen gases, much like a dirty snowball of large proportions.  At most, it is believed from recent observations that the nucleus of Halley's Comet may be 15 kilometers long and 8 kilometers wide....large, but certainly not so large as to fill the huge spaces between the planets and smaller than most asteroid bodies.

2) Comet are fiery furnaces of impending flame - big-time false.  Comets are very cold, surviving in the extreme near-absolute-zero depths of space; only when they get close to the sun's energy and solar winds do we even see them, and at that time most are still frozen chunks of vapor and planetary debris.
3) Then if the comet is cool, why does it have a fiery tail? - it has a tail, but not aflame....a comet is seen from both REFLECTED light (sunlight reflecting from tiny particles of dust as well as from some larger molecules of gases) and from IONIZATION, a process that is very, very similar to "why we get light from a fluorescent light bulb."  In such a light there is no filament to glow like in a light glows through rare gases that become excited when your home the fluorescent light is seen because it has electricity exciting the gases inside....a comet is similar, but is using the energy of the sun.
4) Some comets are so large that they will fill the space between the earth and moon. - true and false on this mentioned the "real comet" or nucleus is but a small chunk less than a mile in diameter.  But as this chunk reaches the heated and energized realm of the sun - about to the orbit of Mars - it begins to give off gases that glow....THOSE gases - the coma or head of the comet, albeit very thin and of very little density, will reach diameters that can exceed over one-quarter million miles.
5) And these gases contain poisons..... - true.  But let's look at this a moment.  Cyanide was indeed found in Halley's Comet prior to its pass in 1910
( ) in the form of Hydrogen Cyanide....but so is this found in common drinking water, the air that we breathe and most other places.  Comets contain possibly ALL of the organic molecules that are found elsewhere in the solar system.....particularly on earth.  So really what comets have is pretty much the same stuff we are exposed to here at home, only much less of it.
6)  A comet's tail can stretch across the entire solar system - nope, not quite.  Just like the comet's coma, the tail is nothing more than just dust and gas.  Now, that being said, each time a comet makes a pass by the sun, particularly if very close, it is very likely to break apart ever so slowly into smaller pieces; eventually this will result in some debris being left in its wake which the earth WILL indeed "run into" on occasions, typically once yearly as the earth makes one complete trip around the sun.  Such encounters result in brilliant (sometimes) "meteor showers" in which hundreds if not thousands of "shooting stars" are seen streaking harmlessly across the sky.
7) Even in Biblical times and accounts, comets were thought to foretell disaster - yes, unfortunately.  However, in simpler times there were "simpler people" without the benefit of the knowledge that we have today....they did not understand comets and the fear of the unknown is greater than any other fear that the human race has.  NOT KNOWING is chaos, essentially.  So, when events occurred that made no rational sense - wars, famine, droughts, floods, odd animal behavior, insanity, deaths of loved ones and revered kings and rules - SOMETHING had to be blamed:  the comets.
Enjoy the comets.....
In any given year there may be a couple of comets bright enough to see with the naked eye and binoculars....we should be so blessed.  They are in essence, God's gift as a reminder that Creation is still going on.  With the horribly light-polluted skies of our modern world the nocturnal pleasures of night and its mysteries are rarely seen anymore.
So....enjoy the comets when they come.  Do not fear them as they are as a normal part of this grand Universe as you and me....only WE don't have tails.
Dr. Clay
Arkansas Sky Observatory
MPC/cbat Obs. H43 / Conway
MPC/cbat Obs. H41 / Petit Jean Mountain


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