The Song of Urania

We turn to the astronomy of Mesoamerica, with a particular focus on the Maya and Aztec. The central feature of their astronomy was a pair of interlocking calendars which regulated all aspects of life. The surviving Maya manuscripts also deal extensively with the motion of Venus, which may also have driven decisions to go to war. We also look at the famous Aztec Sun Stone, the 2012 phenomenon, and the fall of the Itzá Kingdom. NOTE: The Song of Urania will be going on hiatus and will return on the first full moon of 2026.

The most important application of astronomy in Polynesian societies was oceanic navigation. Polynesian navigators regularly traversed from one small island to another across hundreds of miles of open sea. To accomplish these feats of seafaring, they relied on an intimate knowledge of the night sky.

Aboriginal Australian societies are believed to be among the oldest continuous cultures on the planet. Some of their oral traditions appear to preserve a cultural memory of celestial events from multiple millennia in the past. Aboriginal Australians were also keen observers of the heavens and recognized phenomena both common and rare, from the solstices, to solar eclipses, to auroral sounds, and stellar variability.

In his second attempt, Matteo Ricci was able to gain access to the Forbidden City. Over the next century, the Jesuits came to surprising influence in China through their knowledge of European astronomy, though this journey was not without its perils.

After the fall of the Mongol Yuan Dynasty, the Ming Dynasty drove the few small Nestorian Christian communities in China underground and largely closed China off to foreigners. Only in the 16th century with the arrival of Portuguese traders did contacts with the West begin to be revived. The newly founded Jesuit order organized a mission to China led by Matteo Ricci. After finding his efforts at establishing a presence in the country stymied by the government, Ricci discovered that the key to securing a permanent Jesuit presence in China was his knowledge of Western astronomy.

After Wang Mang had usurped the Imperial throne, a disastrous series of reforms led to the collapse of his dynasty. The reestablishment of the Han Dynasty called for yet another calendar reform. About a millennium later, a group of officials, including the astronomer Shen Kuo, instigated a treacherous period in court politics by pressing for a radical set of reforms called the New Policies.

After Wang Mang deposed the Han Dynasty and instituted his new Xin Dynasty, he needed to promulgate a new calendar to mark the occasion. One of his court astronomers, Liu Xin, developed a new calendar that integrated the lunar and solar cycles with the planetary cycles and imbued it with numerological significance. We then talk about how Huan Tan, another astronomer of the era, would have gone about measuring the lunar mansions.

We learn about the political events and omens that led to the calendar reform of 104 BC.

We turn to the ways that the Chinese Emperor's astronomers predicted and interpreted eclipses, as well as the so-called "guest stars" that they occasionally reported observing in the skies. Then we discuss the role of the planets, particularly Jupiter. Towards the end we hear a few examples of astronomy in Chinese folklore.

This month we turn to the astronomy of China in the early Imperial Era. We look at the way that the Emperor's astronomers were organized within the imperial bureaucracy and then walk through the three significant cosmological theories of the era.

We start to explore the relationship between the heavens and the Earth in Ancient China, along with the role of astronomers. One of the most important concepts in Chinese political thought to emerge from this was the Mandate of Heaven. Finally, we look at the oldest record of Chinese astronomy, the story of the astronomers Xi and Ho.

In our final episode on ancient Indian astronomy, we tour the five astronomical Siddhantas, and then meet some of the astronomers whose names and works survive to us, most importantly, the great Aryabhata.

We delve into the contents of the Vedanga Jyotisha, the earliest Indian text to deal explicitly with astronomy. Then we turn to early Hindu cosmology and their explanations for various celestial phenomena, from the phases of the Moon to solar eclipses. Lastly, we briefly cover the unique cosmology of the Jains.

India developed one of the most advanced astronomies of any of the ancient cultures, even rivaling European astronomy in its accuracy by the 18th century. We look at how the geography of India influenced its history and then turn briefly to the little we know about the astronomy of the Harappan Civilization. Finally we end with the astronomy of the Rigveda.

We take a break from the main narrative in honor of this month's blue moon and turn to a somewhat more frivolous topic — how the term "blue moon" came to mean the second full moon in a calendar month.

This month we tour the astronomers of ancient Egypt from the Old Kingdom to the last native Pharaoh of Egypt just prior to Alexander's conquest. We look at how astronomers fulfilled their primary responsibility of keeping track of time during the night so that the priests could perform the appropriate rituals in the temple. Finally, we end our journey through Egypt with their calendar, arguably the most reasonable calendar any civilization has ever used.

Before getting back into Egyptian astronomy proper, we start by looking at Nabta Playa, a site of megalithic activity in the Nubian desert during the late neolithic. Then we turn to the megaliths the Egyptians are best known for — the pyramids. The pyramids have remarkably precise alignments to the cardinal directions and the techniques the Egyptians used to set these alignments remains a mystery. Finally, we look at the largest of the pyramids, Khufu's pyramid, whose so-called ventilation shafts have a possible astronomical connection.

We turn to ancient Egypt, one of the oldest and most beguiling of the ancient civilizations. Egypt is particularly notable for the sheer conservatism of its civilization and changed little in more than two millennia. After a brief overview of its geography, history, and textual sources, we look at Egyptian conceptions of the creation, structure, and end of the universe.

The oldest plausible astronomical artifacts known are African, as are many of the oldest megaliths, around 10,000 of which dot the Sahara and whose orientations are astronomical in character. We then briefly survey some of the creation stories and sky myths from a number of the peoples of sub-Saharan Africa. Finally, we turn to a few of the more unique calendars in the region.

We turn the clock back to the astronomy of the Paleolithic and Neolithic. Clues about humanity's interest in the heavens during the Paleolithic can be seen in linguistic, mythological, and archaeological evidence. In the Neolithic, groups of people constructed tens of thousands of megaliths across Europe, many of which had astronomical connections.