Many ancient civilizations such as the Mayans, Greeks, Egyptians and Sumerians all knew that the planet Venus traced a Pentacle in the sky via a regular transiting cycle. The Pentacle pattern of Venus became ingrained into their mysticism and some of their ceremonies. The alchemists of days of olde were not only wizards but also scholars. Central to their studies was the mastery of astrology and the examination of the paths the planets took as they moved through the sky. Of particular interest was the Pentacle of Venus and the magickal influence they believe it held in the cosmic order of things. Amulets inscribed by the alchemists with the Pentacle were believed to help the wearer obtain grace and honor and to accomplish the heart's desire. The Pentacle of Venus also held special meaning for the Knights Templar which is evidenced in the popular writings and movies of the current day. The first astronomical telescopic observations of the Venusian cycle were conducted by Galileo.
In the same way as these ancient people, most of us recognize Venus by her other titles, the Morning Star and the Evening Star. These titles depend upon her relationship to the Sun as she moves through the sky. The movement of Venus in front of the Sun is known as an inferior conjunction and relates to her title of the Morning Star. The movement of Venus behind the Sun is known as a superior conjunction and relates to her title as the Evening Star. Venus will trace a pentacle in the sky during each of these conjunction cycles as she travels though each sign of the Zodiac. It takes about eight years for each cycle.
If you are paying attention to the dates, you'll notice that one of the conjunctions of the current Pentacle of Venus formed by inferior conjunction occurs in 2012. This date seems to be taking on more and more importance to those people who are caught up in the significance of the meaning of the Mayan Calendar which allegedly ends in December of that year. The Mayans acquired a vast knowledge of Venus cycles and applied them to their calendar. Astronomically, this particular conjunction is a rare event because of its close alignment with the Sun. It happened on June 8, 2004 and again on June 5, 2008 at 15 Gemini. It will repeat again in December of 2017.
Interestingly, if you were to track both the inferior and superior conjunctions at the same time and plotted them out on paper you'd end up with a 12-sided polygon or a Dodecagram which is a 12-pointed star. The Sacred Geometry known as the Dodecagram has been linked to architectural structure of Stonehenge. This leaves room for speculation that some of the ancient architects of Stonehenge might have used Venus cycles as part of an astronomical consideration when plotting the site. (For more about the Sacred Geometry of Stonehenge, click on the sub category titled There's Something About Stonehenge.)