Ancient Astronomy and a Modern Canal
Wendee and I have just returned from a fabulous vacation. We spent much of October cruising from Los Angeles to Mexico, Guatemala, Costa Rica, Panama, and Colombia. By far, the highlight was our transit through the Panama Canal. During this excursion, we also had the chance to consider the history of this unique part of the world.
Do we take for granted that Central America is a poor cousin of the greatness of North America? If we pause to consider what the great Mayan civilization did for us thousands of years ago, we might not be so cavalier. The Mayans developed a powerful philosophy, and most pertinent to this column, they looked at the stars from great pre-Columbian cities like Chichen Itza on the Yucatan Peninsula.
The Mayans lived in what is now the central and southern portions of Mexico, as well as Guatemala and Costa Rica. Their civilization began as long ago as 2000 BCE and stretched to the late Shakespearean period in the early 16th century, a period of more than 3500 years—far longer than our modern period. During this long period, the Mayan astronomers developed two calendars. An early calendar consisted of 260 days, and their later one created a “Mesoamerican year” consisting of 18 months or 20 days each, plus an extra five-day period tacked on. There is evidence that this calendar relates to three eclipse seasons, periods during which eclipses of the Sun and Moon can occur.
The Mayan calendar demonstrates the interest that civilization had in eclipses of the Sun and the Moon. Like the ancient Greeks, the Mayans understood that eclipses occur in cycles, and that any eclipse will repeat itself 18 years, 11 days, 8 hours later. Eclipses then, as now, prove that our sky is a moving, changing place and that its brightest objects, Sun and Moon, often get in each other’s way. The Mayans were curious also about the other wandering things in the night sky, particularly bright Venus, which shines either as an evening star after dusk, or a morning star before dawn. Some Mayans possibly followed the motion of Venus through the open windows and doorways of El Caracol, a proto-observatory structure. And no doubt, comets and strange “temporary stars” (now understood as exploding stars or novae) would have greatly interested them too.
Wendee and I did not get to visit these places during our tour, which highlighted the far more modern Panama Canal. But as our ship navigated that beautiful and fascinating waterway, our thoughts recalled the peoples who so bravely constructed it, and those who came long before, like the Mayans who ruled part of a continent, looked up and measured the stars, and wondered.
