history of stargazing
Across time, different cultures have perceived and utilized the night sky in innumerable ways. Many peoples formed cultural ties to the stars via constellations, some used the night sky for navigation across the seas, and others used the stars for precise measurements of time. For all of us, the cosmos has represented something significant in our cultural history and remains a critical piece of our humanity.
Constellations
Creating images and meaning in the various shapes formed by the stars was a rather significant part of many ancient cultures.
The most widely known constellations today originate from ancient Greece. Greek mythology was the primary source for their constellations; the many heroes of the stories were immortalized into the stars so that they could watch over Earth forever. There were 48 constellations (across 1,022 stars) categorized by Ptolemy, some notable ones include the zodiac constellations, Orion, Aquarius, and so many more.
Chinese officials (the term for Chinese constellations) developed mostly independently from other constellation systems. In the Song dynasty, 283 asterisms (constellations that are not formally defined by the International Astronomical Union) were defined across 1,565 stars. These officials were broken up into four groups, The Twenty-Eight Mansions, and the Three Enclosures. The Twenty-Eight Mansions are split into four categories based on the four cardinal directions: The Black Tortoise of the North, often depicted as a tortoise intertwined with a snake, represents inner struggle and the winter season; The Azure Dragon of the East, also known as Qinglong, is a Dragon God signifying spring; The Vermilion Bird of the South, represented by a fiery bird (usually a red pheasant) is associated with summer; The White Tiger of the West symbolizes strength and courage, and coincides with autumn. The Twenty-Eight Enclosures included stars not visible year-round, but instead in an ecliptic coordinate system based on the path of the moon. The Three Enclosures were then “The Purple Forbidden Enclosure”, “The Supreme Palace Enclosure”, and “The Heavenly Market Enclosure”, which included stars visible year-round from China.
Australian Aboriginal peoples saw constellations not just through the stars, but also through the dark spaces between them. Most notably, “Emu in the Sky” consists of dark nebulae that form the depiction of the large Australian bird. The movement of the constellation helped Aboriginal peoples plan cultural events and forecast changing seasons!
Navigation
Stars, unlike the planets, remain in relatively fixed celestial positions in the night sky year round (only the time at which they rise changes throughout the Earth’s orbit). Each star has a unique declination, angle relative to the celestial equator, and hour angle, measured in degrees or time. Combined, a star can be used to provide an acutely accurate heading when no other landmark is available. The Polynesians were the masters of celestial navigation, employing a technique referred to as Polynesian wayfinding. Polynesian wayfinding consisted of observations of bird behaviors, wave patterns/swells, cloud formations, Te Lapa (a light phenomenon where a streak of light lies just beneath the surface of water, and originates from islands), and of course, the night sky.
Since each star could be used to provide an accurate heading, sequences of rising stars would be memorized to follow along a given oceanic route (A star near the horizon would be the heading, until it got too far into the sky and a new star near the horizon took its place). They also knew when certain stars would pass over certain islands, which allowed navigators to gain a sense of latitude! The Polynesians were not the only ones to use the stars for guidance, The Vikings, Ancient Chinese Mariners, Egyptians, Mesopotamians, and many more all utilized the stars for navigation in some way.
There were also numerous technological advancements relating to the stars that allowed for greater navigational ability. Notably, the Astrolabe was an ancient Greek device that allowed for precise astronomical positioning. The Mariner's Astrolabe was a device that was made to be able to calculate latitude from the position of a known star and was designed to function even in rough seas. The Sextant was a device that came later and was capable of measuring the angular distance between any two objects in the night sky. It functioned by shining a beam of light out towards the horizon and then measuring the angle from there to an observed star.
Timekeeping, Architecture, and Agriculture
Through meticulous records of the movements of the sun, moon, planets, and stars, the ancient Maya created intricate and precise calendar systems capable of accurately predicting astronomical events.
The Maya recorded notable recurring events such as the equinoxes/solstices, and more significantly to them, the zenith passages (when the sun positions itself directly above a given point on Earth). The awareness of these events is seen in specific Maya architecture. Most notably, the Maya observatory at Xochicalco has a hole in the ceiling which when the sun passes over during zenith depicts a sun-like image on the floor. The Maya also observed the movement of the planets, most notably Venus which to them was representative of war. They would plan wars around the positions of Venus, and prisoners of war would be sacrificed in accordance with Venus’ position in the night sky. Less important to the Maya were the stars themself, as they remained mostly motionless and thus were not as interesting to them. Though, the stars were used to predict the changing seasons, and help with agricultural cycles.
Many parallels can be drawn between the Maya and Ancient Egypt. Similar to the Maya, the Egyptians built pyramids and temples aligned with the sun and stars. Notably, the Egyptian pyramids are aligned to the pole star (a star located near the axis of rotation), and the Precinct of Amun-Re was designed so that the rising sunlight on the winter solstice would illuminate an otherwise unlit corridor. Most significantly though, Egyptians used the rising of the star they referred to as Sothis (Now known as Sirius, the brightest star in the night sky) as a signal for the annual flooding of the Nile River. This flood would bring water to dry lands and mark the beginning of the next agricultural season.
Lots of other cultures also utilized the night sky for timekeeping. Notably, the Pueblo Native American tribes utilized a lunar calendar system in conjunction with their agricultural cycles. The Hopi Native American tribe had a twelve-month calendar system that guided their seasonal rituals and work. Looking to the stars for answers is something that has proven monumental to the formation of humanity itself. Stargazing is deeply rooted in just about every culture on the planet and has allowed for many technological and social advancements to come to fruition.
sources
Greek Constellations – Constellation Guide (constellation-guide.com)
Chinese constellations - Wikipedia
Ancient Chinese Astronomy: History, Myths & Facts - China Underground (china-underground.com)
Ancient Mayan Astronomy: the Sun, Moon, and Planets (thoughtco.com)
Australian Aboriginal astronomy - Wikipedia
The Role of Stars in Navigation (starregister.org)
Polynesian navigation - Wikipedia
Native American Astronomy: Ancient Discoveries and Contributions - Native Tribe Info
Egyptian astronomy - Wikipedia