Scientists have incredibly advanced tools to look at the stars today, but in the era before light pollution, star-gazing was much easier and simpler for the average person—just step outside at night. Pretty early on, and in a variety of cultures, people realized that they could chart the stars and their movements for navigation. The Greek constellations, which were tied to their myths, illustrate how this information moved through time. But humanity’s early star maps are much more than ancient artifacts—they became part of our history and culture, and continue to inform modern science to a surprising degree.
The first complete star map that still exists today was made in 650 A.D. in Dunhuang, western China, a city on the Silk Road. There, a star atlas was meticulously drawn onto a piece of paper, then filed away with other documents in a temple alcove. The space was sealed off at some point, and wasn’t re-discovered until 1907, when a Taoist monk, the self-appointed guardian of the temple, accidentally crashed through a wall to find the hidden cache, which contained sculptures, piles of documents, and the now-famous star map.
“[The map] was most likely made by someone highly educated like a scholar or a court astronomer,” cosmologist Dr. Khee-Gan Lee, a NASA Hubble Fellow at the Lawrence Berkeley National Lab, tells Gizmodo. “This was definitely not amateur work, but was professional for the time.”
Lee is an expert on ancient star maps who has given several presentations on them at U.C. Berkeley over the past few months. The history of star maps matters to him personally, because even today, maps of the cosmos help guide his research.
“Mapping out what we can observe…is one way of inferring some of the fundamental parameters of the universe,” Lee said. A good example of how this works is the recent Dark Energy Survey, which used information about the shapes and distribution of galaxies to “infer the density of gravitational matter in the…