Read The Great Christ Comet Online
Authors: Colin Nicholl,Gary W. Kronk
Tags: #SCI004000/REL006710/REL034020
We have mentioned Ignatius and the
Protevangelium of James
, but what did the first generations of Christians claim about the brightness of the comet?
First, Revelation 12:2, 5 would seem to imply that the coma of the comet, in playing the role of the baby that grew in Virgo's womb and then seemed to cause her intense agony as it was “born,” grew very large. It may possibly be inferred from this account that the coma became as large relative to Virgo as a newborn baby is in comparison with its mother: something like 9â12 degrees long (major axis), on October 20, 6Â BC. That would be astonishing, because only a coma that had a strong apparent magnitude value would have a sufficiently great surface brightness at that size to be clearly visible to the naked eye. At apparent magnitude -9 to -11 (n=3, assuming that the comet was first seen between May and December, 7Â BC), the large coma would have been easily detectable but it would not have been stunningly bright. At apparent magnitude -11 to -13 (n=4) it would have been more striking, with a surface brightness like that of Neptune (seen through a telescope).
37
Magnitude -13 to -16 (n=5) would have made for a stunning sight, with a “surface brightness” like that of Saturn.
38
Second, we may perhaps tentatively glean indirect clues about the comet's brightness from texts that speak of Jesus in terms of the comet that heralded his birth. In particular, it is possible to detect some information about the comet's brightness from how New Testament texts draw upon Isaiah 9:2's great oracle concerning the coming of the Messiah and the great natal star: “The people who walked in darkness have seen a great light; those who dwelt in a land of deep darkness, on them has light shone.” Luke 1:78â79 and Matthew 4:16 speak of the Messiah's coming in terms drawn from Isaiah's oracle, as does the Gospel of John.
Luke speaks of a rising star that “shall visit us from on high to give light to those who sit in darkness and in the shadow of death, and to guide our feet into the way of peace” (Luke 1:78bâ79). The language describes a celestial
entity that will rise and become so bright that it will powerfully overcome the darkness, enabling travelers to walk safely by its light during the night hours. The point made by Zechariah (John the Baptist's father) and by Luke is that the Messiah's ministry will be like the great comet that marked his nativity, powerfully dispelling the darkness of night.
Matthew 4:16 claims that, through Jesus's ministry in Galilee, Isaiah's prophecy concerning a great light shining in the deep darkness came to fulfillment: “The people dwelling in darkness have seen a great light,” and “a light has risen” on “those dwelling in the region and shadow of death.” We remember that in Genesis 1:16â17 there are only two “great lights,” so denominated because of their large size and more intense brightness. Matthew, following Isaiah, is claiming that there was a third great light. It powerfully vanquished the darkness, penetrating even into dark shady places. This great light is Jesus. As we observed earlier, Matthew's rewording of Isaiah 9:1â2 hints that what the Star at the time of Jesus's birth did literally in fulfillment of that oracle (“has risen”), Jesus did morally and spiritually in fulfillment of it.
Luke and Matthew therefore describe Jesus in terms drawn from Isaiah's oracle about the great light that would attend the Messiah's birth. These Gospel writers seem to assume that this great light had a brightness at least equal to that of the full Moonâprobably greater.
The Gospel of John may also offer some indirect clues as to the brightness of the great light that announced Jesus's birth. In this Gospel Jesus is said to be “the light of men” (John 1:4b) and “the true light, which gives light to everyone” (v. 9), and he calls himself “the light of the world” (8:12). Moreover, John describes this light as shining in the darkness but not overcome by the darkness (1:5), and Jesus claims that the light is sufficiently bright to dispel darkness (8:12). No light other than an astronomical entity can shine very bright light on all of humanity in the whole world. Jesus is probably being portrayed in terms of the celestial luminary that announced his birth (cf. Num. 24:17; Isa. 9:2). The light is more like the Moon than the Sun in that it shines during the hours of darkness, but in its intense brightness it seems brighter than the Moon, the planets, and the stars.
From Luke, Matthew, and John therefore we may possibly derive indirect clues regarding the brightness of the great light that marked the occasion of Jesus's birth. What we find is consistent with the other, more explicit evidence that we have discovered regarding the comet's brightness: the comet marking Jesus's birth was astonishingly bright, and this great brightness was a literal picture of the moral and spiritual effect of the Messiah's ministry.
With regard to the brightness of the Bethlehem Star's tail, we have reason to believe that it was at the very least clearly visible around the time of its heliacal rising and specifically on October 20, 6 BC, when, together with the coma, it seems to have formed a scepter stretching across the whole sky. Also, on a night between November 23/24 and November 30/December 1, 6 BC, the comet tail stood up on the horizon and was bright enough to be seen when the Moon was present in the sky.
As a side note, it should also be borne in mind that any comet with a very low inclination (where tail curvature is essentially unobservable, because it occurs on the ecliptic plane) would have a brighter tail than more highly inclined comets, because “there is more material [i.e., dust] along the line of sight.”
39
Moreover, a comet narrowly inclined to the ecliptic has a single, combined gas-dust tail, which is brighter by virtue of this union. In addition, the phenomenon of the forward-
scattering of light would have intensified the brightness of the comet when it was in the general area between Earth and the Sun in the period of Virgo's pregnancy and delivery.
40
Consequently, the Bethlehem Star comet, with its close perihelion pass, would have a dust tail that was strongly curved in outer space but that seemed straight and especially bright, brighter even than its apparent magnitude values would suggest. Furthermore, comets are subject to outbursts, small and large, which boost their brightness.
41
In light of this evidence regarding the brightness of the Christ Comet, we suggest that, while the value of n could have been 3, it is more likely that it was closer to 4 (or even 5). We shall generally assume n=4 when we overview the comet's apparition in 7â6Â BC in the following chapter.
The Shape of the Coma
The Christ Comet's coma was probably elliptical (oval), with the nucleus relatively close to the top of the sunward side, in the month after perihelion. The oval shape is strongly suggested by the fact that it was judged to be playing the part of Virgo's baby during that period. Many comets, especially large, productive comets (such as Hale-Bopp) and comets that pass within the orbit of Mercury (such as the Comet of 1677 [C/1677 H1] and Comet West during part of its apparition in 1975â1976), have this shape of coma. What its form was in the preceding and succeeding period we do not know for sure. Cometary comas are capable of changing shape to a considerable extent during the course of a single apparition. For example, the Great September Comet of 1882 was round until perihelion, when it became notably oval.
42
However, in view of how large and productive the Christ Comet was, it is very possible that it remained oval-shaped throughout its time in the inner solar system.
Naming the Comet
The technical name of the Christ Comet, if we assume the latest possible date of first observation, between December 10 and 17, 7Â BC, should perhaps be C/-6 X1 (Magi) or C/-6 Y1 (Magi). “-6” is 7Â BC. Comets are assigned a prefix P, C, or D, depending on whether they have been observed at two or more passages around the Sun or judged to have a period of less than 200 years (P),
43
or not (C), or have disappeared or are considered extinct (D). In the case of long-period comets, after the prefix the year of the comet's discovery is given, followed by the part of the year when this occurred (in the form of a letter
44
) and a number indicating the order of the comet's discovery relative to others during that period (“1” for the first one discovered, “2” for the second, etc.). If the Christ Comet was spotted earlier in 7Â BC than December 1, then the “X” or “Y” would be replaced by one of the
previous letters of the alphabet (AâW, excluding I), depending on the half-month during which it was first seen. For example, if the comet was first observed on September 30, 7 BC, its proper designation would be C/-6 S1 (Magi). If the comet was first seen in 8 BC, “-6” would be replaced with “-7,” and the letter of the alphabet would be WâY.
Over the last few centuries comets have generally been named after their discoverer(s) or the one(s) who determined their orbit. An example of the former is D/1993 F2 (Shoemaker-Levy 9), which is named after Gene and Carolyn Shoemaker and David Levy. An example of the latter is 1P/Halley, which is named after Edmond Halley (
fig. 9.2
). Since we do not know the name of the particular Magus who first observed the Christ Comet, we have no choice but to attribute the cometary discovery to the whole group. Alternatively, since many historically great comets are designated “Great Comet” (e.g., C/1811 F1 [Great Comet]), “Great January Comet” (C/1910 A1 [Great January Comet]), “Great Southern Comet” (C/1880 C1 [Great Southern Comet]), or the like, it may be preferable to name it “Great Christ Comet” (hence C/-6 Y1 [Great Christ Comet], assuming the latest possible date of first observation).
Conclusion
In this chapter we have sought to develop a profile of the comet, in particular nailing down its orbit and establishing the parameters of its brightness. In the following chapter we shall overview the cometary apparition on the basis of our orbital elements. This will help us get a vision of what the Star of Bethlehem did.
10
Tracking the Comet
In this chapter we will put together the story of the apparition of the Christ Comet, tracking its progress from the point of its first appearance until it stood over the house in Bethlehem. We can do this based on our orbital elements and brightness calculations, the Biblical data, observations of comets over the last few centuries and especially recent decades, and cutting-edge cometary research. It is important to remember that a celestial object's orbital elements fully describe its orbit and enable us to plot the body's location in space and in the sky at any given point in time (planetarium software makes this easy). Our earlier work on the Christ Comet's absolute magnitude, in conjunction with the latest research on cometary brightness, enables us to figure out the comet's apparent magnitude (within a range) at any given point in its orbit.
1
Thanks to the Biblical text, extensive records of historical comets, and modern studies of the behavior of comets such as Hale-Bopp, we are in an excellent position to say something about the Christ Comet's appearance and behavior throughout its apparition.
2
At the same time, we should bear in mind that comets are somewhat individual and are capable of springing surprises on observers, for example, when they have minor or major outburst events, when they inexplicably fade or brighten,
3
when their tails become discon
nected, and/or when they fragment. Nevertheless, it makes most sense for us to assume that the Christ Comet's apparition developed in a reasonably orderly fashion.
If the reader wishes to get a vision of how the cometary coma grew like a baby in Virgo's belly after perihelion, Starry Night
®
Pro software proves helpful.
4
Input the orbital elements along with a large nucleus diameter, the relevant absolute magnitude value, and the terrestrial location, and you will get a good general idea of the kind of thing that the Magi saw.
5
With respect to the growth of the comet tail in length during that period, Project Pluto's Guide 9.0 is the most useful software.
Overviewing the course of the comet during its 8/7â6Â BC apparition serves a number of functions: (1)Â It demonstrates that a long-period, narrowly inclined, retrograde comet is capable of satisfying all the criteria to qualify as the Star of Bethlehem. (2)Â It authenticates Matthew's account of the Star. In view of how ignorant the ancients were concerning comets, there is, quite frankly, no way that anyone could have
invented
such a complex cometary apparition that is perfectly consistent with modern astronomical knowledge. (3)Â It enables us to understand why the Magi were so awed by the Star and why they responded to it by making a long pilgrimage across the wilderness in a bid to find and worship the baby Messiah. (4)Â It reveals why the Bethlehem Star deserves its reputation as the greatest astronomical entity in human history.
It should be noted that sightings of the comet on any particular day/night from any particular geographical location was dependent on favorable atmospheric conditions.
The Comet's Home
The Christ Comet had spent the preceding centuries hidden in the region of the sky associated with the constellation Pisces (“The Tails,” in BabÂyloÂnian parlance
6
), more particularly under Pisces's western/advance fish (
fig. 10.1
). This constellation was the comet's home (from the perspective of Earth), where it long remained in darkness, far from curious human eyes. Surpassing even Hale-Bopp, the Christ Comet probably developed a coma more than 5 years before its discovery, farther away from the Sun than Uranus's orbit (i.e., 20 AU or beyond).
According to our orbit, on May 28, 8Â BC,
the comet, on its way to the Sun, passed about 0.55 AU, that is, about half the distance between Earth and the Sun, from Saturn. This encounter had some effect on the comet's orbit, lengthening it.
7
The First Observation
In our last chapter we suggested that the comet was first spotted between November 21â28, 8Â BC, and December 10â17, 7Â BC. Even the latest possible date of first observation would put the Christ Comet in a super-league of cometary greatness. At this point the comet was as far away from the Sun as Jupiterâit was 4.71â4.63 AU from the Sun (by comparison, Hale-Bopp was first observed when it was 4.37 AU from the Sun) and a little over 5 AU from Earth (see
fig. 10.2
). Back on November 21â28, 8Â BC, the earliest possible date for the first observation of the comet, it was not far short of Saturn's closest distance to the Sunâbetween 8.34 and 8.28 AU from the Sun (and Earth).
A burst of brightness due to a cometary outburst could explain the early sighting. It is not uncommon for comets first to come to the attention of humans when they experience a sharp brightness outburst that causes them to cross the threshold of visibility.
8
However, if that was so, the fact that the Magi were able to keep track of the Star through the following months suggests that the comet was like Hale-Bopp in having copious outbursts, “puffing them out one after another like a locomotive.”
9
When a long-period comet is observed far from the inner solar system, its tail is typically not visible. Because the only observable brightness is concentrated around the nucleus, the comet can appear to be a new star and be initially classified as such. Such a first impression may have been difficult for the Magi to dispel, because the comet's movement against the backdrop of the stars was so slow and slight (due to its great distance from Earth) that it may have been detectable only after weeks of observation.
10
In what circumstances did the Star first appear? Did it have an auspicious beginning? We recall that Herod's preoccupation with the Star's first appearance could conceivably have reflected a concern that the Messiah might have been born at that time. It is important to survey the comet's orbital course during the year between November 8 BC and December 7 BC to see where the comet would have been within the starry sky when the Magi discovered it.
On November 21â28, 8Â BC, the comet would have been in the border region between the constellations of Aquarius the Water Bearer and Pisces the Fishes. Over the course of the following 6 months the comet would have slowly moved toward and under the western fish (the “Circlet”) of Pisces.
According to our orbit, one striking aspect of the comet's movement within the dome of the sky during the year when it first appeared was a conjunction with Jupiter under the belly of the western fish (equated with the stars
κ
and
λ
Piscium) in the constellation of Pisces (with respect to zodiacal sign,
11
it was crossing from Aquarius to Pisces).
12
On the western horizon shortly after sunset between January 30 and February 10, 7Â BC, the comet would have been within 1 degree of the King Planet.
13
Our orbit suggests that the comet came to about half a degree from Jupiter on February 5. By February 10, the date when Jupiter made its last appearance in the western sky, the comet was about a degree from it. On the 5th, Jupiter and the comet would have been in the middle of a line of celestial entities consisting of the Sun and Venus on one side and Mercury and Saturn on the other, all within a 24-degree zone; by the 10th, the zone would have narrowed to 20 degrees.
14
Could the comet have come to visibility at this time? If it did, one could well imagine that it might have seemed to BabÂyloÂnians that Jupiter, the “King,” had begotten a new star. Striking and significant, such a sight would have ensured that the Magi paid close attention to the comet over the following months and years.
However, because the comet was getting very close to the Sun at twilight, it certainly would not have become visible for the first time then unless it experienced a sudden and dramatic surge in brightness, rendering it as bright as Jupiter. That is not impossible, but seems very improbable. For one thing, a first appearance 19½ months before perihelion seems implausibly early.
In the unlikely event that the Magi did observe the comet for the first time in early February of 7Â BC, they would have found themselves frustrated because the comet and Jupiter would have disappeared below the western horizon very shortly thereafter. Having disappeared below the horizon, Jupiter would not have reemerged in the night sky until the middle of March. By the time of Jupiter's heliacal rising around March 17, 7Â BC, it would have been more than 5 degrees from the comet, but both were still located in the constellation of Pisces, below the tail of the western fish. In terms of zodiacal sign, they were firmly in Pisces.
When Jupiter and Saturn had the first of
their three conjunctions in Pisces of 7Â BC, coming to within 1 degree of each other on May 27â31, the comet, if visible, would have been less than 15 degrees away from each of them, still below the tail of Pisces's western fish (and within the zodiacal sign of Pisces).
15
The comet remained below the tail of the western/advance fish of Pisces until mid-July, 7Â BC, and then below its belly until the end of August.
With respect to the comet as it traveled in outer space, it was hurtling toward Jupiter, the gas giant. According to our orbit, it came to about 2.07 AU from Jupiter on July 1, 7 BC.
In August/September, 7Â BC, the comet drifted slowly out of the constellation Pisces into the neighboring Aquarius (“The Great One” in BabÂylon) (
fig. 10.4
), reaching the stream of water that flowed out of the water-bearer's water-jar
16
in mid-September, 7Â BC.