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The Dancing Queen - Venus Observed
Venus is interesting to me because it is so bright and noticeable, yet always fleeting. The sight of Venus must have been spectacular to ancient cultures because of its intensity and notoriety for heralding the day and night. I had intended to watch Venus for the change of phases and to use my data in relating phase changes with the synodic period of Venus. My problem was that I began with the bias that because Venus is an inner planet it should orbit pretty fast and go through phase changes quickly, yet slightly slower than our moon.
I began my observations of Venus, naturally, with my naked eye. It is very bright, "as it is the third brightest object (after the Sun and Moon) and has a magnitude of -4" (Audubon 646). I was astonished to notice that I could still see Venus well after the Sun had risen above the horizon. I went to Starry Night to see how long Venus should be visible in the day. Remarkably, I found that during the day I had been observing Venus, it rose at approximately 4:00 A.M. and set, into horizon light, at 3:30 P.M., if one knows where to look. I was able to see Venus well after sunrise because I saw it rise and kept watch, hence I knew where it would be in relation to the sun.
Photo taken by Keith Clemmons using an Aiptek Pencam through 10x50 binoculars
The binoculars I used to view Venus (10x50) were insufficient to see Venus in a phase. I could barely make out the crescent in binoculars. I am convinced I can see the crescent with my naked eye, as seems possible to Anthony Aveni, who notes that, "the sheer size and brightness of this thin disk raise the possibility that Venus could have been viewed as a crescent without the aid of a telescope" (Aveni 32). According to math, however, it seems impossible. The only reasoning I can find is that I wanted to see it and knew what the phase should look like at the time I saw it.
Click here to see my math on the angular size of Venus
By extending my observations using the Orion 8- inch Newtonian reflector, I was able to see Venus as a crescent on first observation. It was impossible for me to get a still image due to the sun heating the atmosphere over the horizon and creating a "dancing" image of Venus. I had hoped to see more detail, such as dark areas. Moore and Hunt point out that, " more often than not, some vague elusive features will be glimpsed- provided that conditions are good, and that the telescope is of sufficient aperture" (Moore & Hunt 57). Through the Orion, I was unable to notice any change in the crescent's appearance during my observing, let alone elusive features, despite great conditions. With the help of Starry Night again, I was able to see phase changes of Venus for this year. Interestingly enough, the phases of Venus are easily seen changing on Starry Night with a field of view of 11 arc minutes. Yet, it is still hard to discern phase boundaries in the shading, which makes any chances of predicting period from phases a moot point. It is interesting to note that the phase changes are different each cycle because of the relative positions of the Sun, Venus, and Earth.
Click here to see a sketch of Venus displaying phase
I did a study on starry night to find out what a Venus cycle would look like in 1000 A.D. on the Yucatan Peninsula. I drew some sketches and made a movie showing phase change.Venus has different movement patterns in the Eastern sky than in the Western sky. The thing that is similiar about the loops on either side of the sky are the solstices. As the Sun makes its way North and South of the equator, Venus follows suit because it is bound to the sun. The loop that is seen in the Eastern sky is due to the fact that Venus has just left inferior conjunction and is making its way to superior conjunction. This causes Venus to look like it makes a hesitative loop in the sky for several days because Venus is making its turn around the sun relative to Earth. In the Western sky, when Venus is an evening star, it is heading around the sun towards us. This make the large loop pattern because Venus is now moving towards us and because the turn around the Sun towards inferior conjuction, relative to Earth. The small loop in the Southwestern sky is due to the fact that the sun is around winter solstice while Venus is heading for superior conjunction. Check out the drawings and movie below.
Click here to see some sketches of Venus' Eastern and Western sky patterns
Click here for a movie in Quicktime of Venus going through phases
By using Starry Night, I found that Venus follows no regular consistency in the amount of time it remains visible in the Eastern or Western sky, as well as the time it is invisible. If you look at the sketches I made, you will see that Venus spent 208 days in the Eastern sky and 273 days in the Western sky. The period between the Eastern disappearance and Western appearance, 12-30-1000 to 4-4-1001, is around 95 days. These numbers vary year to year. The cycle is not regular.
It would take at least eight years of studying the skies, like the ancient Maya did, to compute the synodic period of Venus. Maor points out that the synodic period of Venus is "the time between two consecutive inferior conjunctions" and that "the Maya calendar may have been based on it" (Maor 55). The Maya, through years of patient observation and mysterious intent, were able to find a connection between Earth and Venus such that "the Venus year (~584 days) meshes perfectly with the length of the year of our seasons, 365 days, in the ratio of 5 to 8" (Aveni 30). I have found no evidence that the Maya calculated Venus' sidereal period. How could they unless they had an understanding of the solar system? It seems to me that Venus' sidereal period was a discovery beyond the scope and practicality of Maya astronomers. Why would they need to know the sidereal period of Venus? It is what they saw that was important. It seems as if I should take a step back, and not worry about phases as much as movements, and connections. In other words, perhaps the Goddess of Love is best viewed with a naked eye, free of obscurities.
Click here to see some pictures of Venus rising over highway 101
Cyclic Nature - Use of Venus by the Maya
How did the ancient Maya use their observations of Venus? To answer this I strive to eliminate my modern preconceptions because, "unlike her ancient counterpart, the modern Venus is no lady; instead she moves about a vaster sky, an inanimate object to be entered, and dissected with Venera and Magellan spacecraft" (Aveni 17). I strive to envision this "ancient counterpart"; to envision myself as part of an ancient, highly ordered society, which is intricately connected to the movement of the lights in the Sky.
"For the classical Maya, the continuity of the power of rulership was directly expressed from the sky-creator in the form of discernable subtleties in observable planetary cycles-Venus most prominent among them" (Aveni 16). Since Venus is the brightest planet and has an unusual cycle, it seems a likely candidate for predictive power. The position of a ruler atop a pyramid, with Venus setting or rising over the ruler's head, would definitely have a powerful effect on a society that deified stars and planets. "By taking his place at the apex of the symbolic program, the king declared himself to be the causal force that perpetuated this order" (Schele & Miller 106). Venus myth also plays an important part in the divine right to rule. For example, a Maya creation story portrays Venus as a "twin who goes into the underworld with his brother the sun to battle these lords of pestilence" and ends up tricking the fiends, making the world what would otherwise be "far worse off with disease than it is today" (Aveni 50). By relating this myth to the quote at the beginning, we can begin to see how the Maya king held great authority through the cosmos. It also seems appropriate that Venus is the sun's twin in this mythology, seeing how Venus is always close to the sun and shines brightly. Mythologies seem to have been of great importance to the Maya, because there are several depictions of superhuman characters on all the Maya temples. I use great skepticism in making any claims that the drawings on Maya temples are myth or deity related, though it seems likely. I find a lot of what I've read to be indigestible. How can we really be sure what we are seeing is what the Maya saw? It is ridiculous to think we can. In none of the books I researched, do they describe how they interpreted the Mayan glyphs. How are they sure that the Venus symbol is not the moon, or a bird in the area? I didn't find good proof for these uncertainties, which disappointed me greatly and leaves me very skeptic. Perhaps the kings were not being worshipped and deified by the sight of Venus, but rather the kings were the leaders in the worship of Venus, their deity.
I found that it is also possible that Venus was used for agricultural purposes, in order to know when to plant and harvest. The sun is generally assumed to represent seasonal changes among ancient cultures, so it is a surprise to find that the disappearance time of Venus "is a good index of when the wet and dry periods happen in the seasonal cycle" (Aveni 5). The "good index" might be the average time of disappearance of Venus instead of an actual date to expect the rain. For example, the rainy season, or dry season, may be nine months long, the average disappearance time of Venus in Central Mexico. Imagine being an ancient sky watcher and seeing a correlation of rainy season and Venus appearances. This might be a good crop planting predictor. While waiting for the sun to rise one spring morning, an ancient Maya might have noticed Venus appearing from a long absence and begun the crop planting on that sighting of Venus, knowing the rain was coming. It is not surprising then to find that the Venus symbol is commonly portrayed with Tlaloc, the "god of the storm, rain, and lightning…his meteorological power controlled agricultural fortunes" (Krupp 257). This does not make sense if we look at the irregularity of Venus appearances in different months. This does make sense if we give the 260 day average disappearance of Venus a loose relationship to the rainy season. Interesting enough, I found the climate for Belize to match this fact. I chose Belize because it is in the middle of the Maya civilization.
Click here to see the average rainfall in Belize
It is further suggested by Krupp that Venus was tied to ritual warfare and that by "combining the agricultural abundance implicit in the rains with the status and wealth that accompany tribute won through war, the imagery of Tlaloc-Venus aggression operated as propaganda" (Krupp 257). It seems to me that the Mayans must have needed a good form of advertisement in order to reach all the people under Mayan rule. This makes the deity/planet association even more convincing, but it may be more complex. Perhaps the planets and stars operated on many levels of deities. Or maybe it was simply the Mayan calendar, in which Venus is contained, that was the prognosticator of war and harvest. It is unknown either way, but we can speculate. An interesting coincidence occurs on August 2, 792. On that day Venus was in inferior conjunction and the sun passed through the zenith (Krupp 259). A mural found at Bonampak, interpreted by Floyd Lounsbury to depict events from this date, is supposedly "illustrating battle, sacrifice, and the subjugation of prisoners taken in war" (Krupp 259). Whether we can believe Floyd's interpretation or whether the Maya planned their attacks for this celestial combo is up in the air. We will probably never know.
Furthermore, there are fascinating links between the Mayan calendar and Venus that I cannot ignore. The Mayans had a Venus count of 584 days, representing Venus' synodic period (Aveni 7). As I mentioned before, this cycle is matched with the 365-day solar year by a 5/8 ratio. There was also a sacred calendar derived by the Mayans. The Mayan Tzolkin calendar, or Sacred Round of 260 days, may be related to the fact that Venus (as seen from southern Mexico) "lingers and rises in the east as many days as in the west…period of 260 days" (Aveni 78). Is it possible that the Mayans related Venus cycles to the moon cycles as well? To find the relationships of these calendars mathematically, I tried to plug in some numbers and see what I came up with myself. I used a synodic moon period average of 29.5 days and a solar year average of 365.0 days (Audubon 635). Here are my calculations:
Both the Venus cycle recorded by the Mayans and the Tzolkin calendar are more evenly divisible by the moon's synodic period than the modern Gregorian calendar we use. It was interesting to see that the closest whole number match, indicating preciseness, is eight solar years and five Venus cycles, divided by the moon's synodic period. This is important to pay attention to because it could let us see into the minds of the ancient Maya calendar makers. The Maya probably created such an elaborate calendar to try to find order in the cosmos. In mathematical terms, this would mean finding the correlation between cycles of multiple heavenly bodies (i.e. 5 Venus years = 8 solar years = 99 moon cycles). For all practical purposes, 98.9 would be close enough to 99 for the Maya. Is this evidence of an intricate association between observed cycles of the three brightest heavenly bodies? It could just be math games. Although, if one believes the myth of the Mayan kings' divine rights through the heavens, the Venus/Moon connection becomes interesting. A Mayan astronomer might have recognized that the moon is in just about the same phase at each Venus cycle renewal. This predicted knowledge could have made the king look bound to the sky in the eyes of observing commoners. Or perhaps it was a need to find a pattern in nature, a way to find order. For after all, order is the base goal of any calendar.
Works Cited:
Aveni, Anthony. Archaeoastronomy in the New World. Great Britain: Cambridge University Press, 1982
Aveni, Anthony. Conversing with the Planets. New York: Times Books, 1992.
Freedman, Roger and William Kaufmann. Universe Fifth Edition. New York: W.H. Freeman, 2000.
Hunt, Gary E. and Patrick Moore. The Planet Venus. Boston: Faber and Faber, 1982.
Krupp, Edwin C. Skywatchers, Shamans, and Kings. Canada: John Wiley & Son, 1997
Maor, Eli. June 8, 2004: Venus in Transit. New Jersey: Princeton University Press, 2000.
Miller, Mary Ellen and Linda Schele. The Blood of Kings. New York: George Braziller, 1986
National Audubon Society. Field Guide to the Night Sky. New York: Knopf 1991.