Star charts are maps of the night sky that have helped people find their way and understand the universe for thousands of years.

Key idea: The earliest star charts date back tens of thousands of years, found in ancient carvings and artifacts, showing humanity's long history of observing the night sky.

Humans have been drawing star charts for an incredibly long time, even before written history. Scientists have found many old sites and objects that seem to be early forms of star charts.

One of the oldest possible star charts is a carving on an ivory tusk from a mammoth. It was found in Germany in 1979 and is about 32,500 years old. Some believe the carving looks like the constellation Orion, though it is not certain. It could also be a chart related to pregnancy.

Another fascinating example comes from the Lascaux caves in France, dating back 33,000 to 10,000 years ago. A German researcher, Dr. Michael Rappenglueck, thinks a drawing there might show the Pleiades, a cluster of stars. He also suggested that other drawings in the same caves, showing a bison, a man, and a bird's head, might represent the Summer Triangle, a group of bright stars that was visible all night long in that era. He also found a drawing of the Northern Crown constellation in the El Castillo cave in Spain from the same period.

Another ancient star chart, over 21,000 years old, was found in the La Tête du Lion cave. It might show the constellation Taurus, with the Pleiades nearby. There is also a star chart from Kashmir, India, from 5,000 years ago, which is believed to be the first to show a supernova, a huge star explosion.

The Nebra sky disk, a bronze disk from about 1600 BC, is another famous example. It has gold symbols that many believe represent the sun or full moon, a crescent moon, several stars including the Pleiades, and possibly the Milky Way galaxy.

“The oldest known star chart may be a carved ivory Mammoth tusk, drawn by early people from Asia who moved into Europe, that was discovered in Germany in 1979.”

Key idea: Ancient civilizations like the Egyptians, Babylonians, Chinese, and Greeks developed more systematic and detailed star charts and catalogs, often for religious or navigational purposes.

As civilizations grew, so did the detail and accuracy of star charts. The oldest star chart that we can accurately date comes from ancient Egypt, around 1534 BC. The Babylonians in Mesopotamia also created very early lists of astronomical objects in the late 2nd millennium BC.

In China, records of astronomy go back to the Warring States period (476 to 221 BC). The oldest Chinese star catalogs we still have were written in the 2nd century BC. The earliest Chinese picture of the night sky is on a lacquerware box from the 5th century BC. This box shows the names of Chinese constellations but not individual stars.

A famous Roman copy of a Greek statue, called the Farnese Atlas, from the 2nd century AD, shows the Titan Atlas holding a globe with the ancient Greek constellations. This statue is important because it is the oldest surviving image of these constellations and includes lines that show their positions. By studying these positions, experts figured out that the original observations for this map were made around 125 BC, likely using the star catalog created by the Greek astronomer Hipparchus.

Another example from the Roman era is the Dendera zodiac from Ptolemaic Egypt, dating to 50 BC. This is a carving on a temple ceiling that shows the zodiac signs, but it does not plot individual stars.

Key idea: The medieval period saw the creation of the oldest surviving complete star chart manuscripts and the development of more detailed and accurate star maps across different cultures.

During the medieval period, star charts continued to advance. The oldest complete star chart manuscript that still exists is the Dunhuang Star Chart. It was made during China's Tang dynasty (618 to 907 AD) and found in a cave along the Silk Road. This long scroll, about 210 centimeters long, shows 1,345 stars grouped into 257 constellations. It is thought to have been created around 705 to 710 AD.

Later, during the Song dynasty (960 to 1279), the Chinese astronomer Su Song created a book with five maps showing 1,464 stars in 1092. In 1193, another astronomer, Huang Shang, made a star map that was later carved into stone in 1247 and can still be seen today.

In the Muslim world, the Persian astronomer Abd al Rahman al Sufi created what is likely the first accurately drawn star chart in his 964 AD book, 'Book of Fixed Stars'. This book updated earlier works and included illustrations of constellations with brighter stars shown as dots. A copy of this book from around 1009 is kept at Oxford University.

The oldest known European star map is a parchment manuscript from 1440, likely made in Vienna, Austria. It showed the constellations of the northern sky. This might have been a model for the first printed European star chart, a set of woodcut prints created by Albrecht Dürer in Germany in 1515.

“The oldest surviving manuscript star chart was the Dunhuang Star Chart, dated to the Tang dynasty (618 to 907) and discovered in the Mogao Caves of Dunhuang in Gansu, Western China along the Silk Road.”

Key idea: The Early Modern period, driven by global exploration, significantly expanded star charts to include the southern hemisphere and introduced standardized naming systems for stars.

The Age of Discovery in Europe led to explorers traveling to the southern hemisphere. This meant they saw stars and constellations that Europeans had never mapped before. New constellations were added to star charts, often based on the observations of Dutch sailors like Pieter Dirkszoon Keyser and Frederick de Houtman in the late 1500s. Their findings were included in a globe by Jodocus Hondius in 1601, which added 12 new southern constellations.

A very important star atlas from this time was Johann Bayer's Uranometria in 1603. This was the first atlas to map both the northern and southern skies. It also introduced the system of using Greek letters to name the brightest stars, which we still use today. The Uranometria contained 48 maps of the constellations known to Ptolemy, plus new southern constellations and maps of the entire northern and southern hemispheres.

Later, in 1690, the Polish astronomer Johannes Hevelius published his star atlas, Firmamentum Sobiescianum. It had 56 large star maps and made the positions of southern stars even more accurate. Hevelius also added 11 new constellations, such as Scutum, Lacerta, and Canes Venatici.

Key idea: Modern star charts continued to innovate with new ways to visualize and interact with the celestial map, making them more accessible and engaging.

In more recent times, star charts continued to become more detailed and innovative. In 1824, Sidney Hall created a unique set of star charts called Urania's Mirror. These were based on an earlier atlas but had holes punched in them. When you held them up to a light, the holes would light up, showing the stars of the constellation in a very visual way.