comet 46p wirtanen dec 2018.png

As you may have already heard, there is a comet passing through our part of the solar system, Comet 46P/Wirtanen.

This article from Sky and Telescope gives one of the better discussions of the comet and its current pass through our inner solar system, predicted to reach its closest approach to earth on December 16 (Sunday).

That article also includes a good star chart diagram showing the path of the comet as it moves through the background of stars on successive days, which you can see here.

Above, I have created a star chart using Stellarium showing the general orientation of stars for a viewer in the northern hemisphere, and indicating the approximate location of the comet on December 13 (tip of the lowest yellow arrow), December 16 (tip of the middle yellow arrow) and December 19 (tip of the topmost yellow arrow).

Note that the best celestial "landmarks" for finding Comet 46P/Wirtanen on this 2018 approach include the V-shaped Hyades and the brilliant cluster of the Pleiades. Below, I reproduce the same star chart shown above, this time with the Hyades and Pleiades labeled. I have also labeled the outline of the mighty constellation Orion, with whom I assume most readers are familiar:

comet 46p wirtanen dec 2018b.png

Personally, I have been out on two successive nights now (last night the 12th and this evening the 13th) and have not been able to locate the comet using binoculars, even though I was able to easily identify the two small stars in the constellation Taurus indicated near the tip of the lowest yellow arrow (where the comet is passing on December 13). These two stars can be seen in the charts above at the end of the green line which extends from the point at the bottom of the "V" of the Hyades (the constellation outlines included in these charts are a conventional outlining system used on Stellarium as a default -- readers should use the constellational outlines suggested by H. A. Rey for finding the constellations and for perceiving their connection to ancient myth, but I have included the conventional outlines above because they give a line from the "V" of the Hyades to stars that might serve as useful referents for locating the comet).

However, the comet is expected to become somewhat brighter on the following nights as we approach the 16th, and it will also be movin go a location between the Pleiades and the first star in Taurus behind the Hyades (the first star which that green line connects to, behind the point at the bottom of the "V" of the Hyades).

Below is a computer animated model showing the orbit of Comet 46P/Wirtanen from the point of view of an observer slightly above the plane of the orbit of the planets, and at a distance beyond the orbit of the planet Mars (the path of Mars is indicated by the red oval in the animation):

image: Wikimedia commons (  link  ).

image: Wikimedia commons (link).

From the above diagram we can readily observe several important aspects of the orbit of Comet 46P/Wirtanen. First, the orbit of the comet, which is indicated in bright magenta, comes very close at its farthest point to the orbit of the planet Jupiter (Jupiter's orbit is indicated in gold on the animation). This means that Comet 46P/Wirtanen is a short-period comet: one whose orbit takes fewer than 100 years (and indeed, Comet 46P/Wirtanen's orbital period is now less than 6 years per orbit).

Second, we can see that Comet 46P/Wirtanen is orbiting in the same orbital direction that the other planets shown are orbiting our sun. In the computer animation, the sun is indicated in yellow (of course: it is the circle in the center of the orbiting planets). The planet Mercury is shown in green, with a green orbit, closest to the sun. Next out from Mercury is the planet Venus, shown in turquoise with a turquoise orbit. Next of course we find our earth, shown in blue with a blue orbit, and then Mars in red with a red orbit. Just outside of the magenta path of Wirtanen we see the orbit of Jupiter, shown in gold.

You can see that Comet 46P/Wirtanen is orbiting in the same direction as the planets are in their own orbits around the sun. This means that the comet is "prograde" as opposed to retrograde in its orbit.

Finally, you can see that although the orbital plane of the comet differs slightly from the plane upon which the planets are orbiting, the orbital plane of the comet is not tilted very much relative to the plane of the ecliptic upon which the planets generally orbit. The animated model shows a series of lines above or below the magenta arc of the comet's orbit in order to indicate when the comet is below the plane of the other planets (lines going above the comet's magenta path) or above the plane of the other planets (lines going down below the comet's magenta path).

All of these features are highly characteristic of short-period comets, as Dr. Walt Brown explains on this page of the comet chapter of his book, In the Beginning: Compelling Evidence for Creation and the Flood. Fully 97% of the 737 known short-period comets are prograde in their orbital direction, with only 3% of them orbiting in a retrograde direction. This weighting is in marked contrast to the 298 known long-period comets, which are nearly half-and-half prograde versus retrograde in number.

Additionally, as the discussion in the linked page by Dr. Brown reveals, the great majority of short-period comets have a low angle of orbital inclination versus the plane of the orbits of the planets, whereas the long-period comets come in towards the sun from all kinds of different orbital planes, some of them very steeply inclined versus the plane of the orbit of the other planets.

And, it is notable that Comet 46P/Wirtanen's aphelion is very close to the orbital distance of the planet Jupiter. This fact indicates that Comet 46P/Wirtanen is a member of the group of short-period comets known as "Jupiter's Family" whose aphelions bring them out to a range of four to six astronomical units from the sun (an astronomical unit or AU is a unit of measurement derived from the average orbital distance of our earth from the sun on the long axis of our orbital path, equivalent to about 93 million miles). Jupiter orbits at an average of 5.2 AU from the sun, or about 5.2 times the average distance of earth's orbit.

As Dr. Brown explains on the webpage linked above, these characteristics of the known short-period comets orbiting our sun (their low inclination relative to the orbits of the planets, their overwhelmingly prograde orbital direction, and their tendency to have aphelions which take them out to a distance close to the orbital distance of Jupiter) all argue that these comets did not originate from some hypothetical "Oort Cloud" far beyond the farthest planets in our solar system, where they were supposedly perturbed and hurtled all the way into our solar system, only to become trapped in an elliptical orbit around the sun.

Instead, these characteristics argue that comets probably originated from some catastrophic event which launched debris outwards from some point in the inner solar system. Dr. Brown argues that they were violently ejected from our own earth itself. Other researchers, including Thomas Van Flandern (1940 - 2009), former Chief of Celestial Mechanics at the US Naval Observatory, have argued that they may have originated from an exploding planet orbiting between the orbital paths of Mars and Jupiter. For more discussion on this topic, see previous posts from very early in this blog's history, such as this one and this one.

Note that early in this blog's history, I was interpreting the Bible literally, but as I began to discover more and more evidence that the figures and events described in the Bible (in common with virtually all the world's other ancient myths, scriptures and sacred stories) can be shown to be based on celestial metaphor, I slowly came to the conclusion that I could no longer believe that the stories in those scriptures were ever intended to be understood as describing literal and terrestrial historical events.

In any case, over the next few nights I hope that you (and I) will have success in seeing Comet 46P/Wirtanen on its 2018 visit to the inner solar system -- and that as we observe this mysterious visitor, it further excites our curiosity to learn more about the ancient history of our planet and solar system, which may very well contradict the conventional narratives we have been told over and over, and which continue to be repeated as though they have already been proven (when in fact they do not seem to be supported by the evidence). 

note from a little after 10pm on night of 12/14:

The comet is now easily visible right where it should be, as suggested by the line imagined between the tips of the arrows in the diagrams. It appears as a hazy blue-green glow when viewed through binoculars (I used 10x50 WA).