Human curiosity for celestial objects has existed for centuries. In ancient times, people didn’t have the advanced tools like we use nowadays in making celestial observations. In ancient times, they relied on sophisticated tools and very simple technology. One of the relics that prove the existence of space research in ancient times is an ancient observatory located in the city of Gyeongju, on the east coast of South Korea.
Cheomseongdae is the oldest astronomical observation in Asia, and is the oldest scientific installation on Earth. Cheomseongdae means star-gazing tower in Korean. It dates to the 7th century to the time of kingdom of Silla, which had its capital in Gyeongju. Cheomseongdae was designated as the country’s 31st national treasure on December 20, 1962.
Cheomseongdae is a simple tower structure made of stone. It was built in the 7th century, during the reign of Queen Seondeok of the Shilla dynasty that ruled the Korean peninsula. Gyeongju is the former capital of the Silla kingdom with the name of Seorabeol. In this city, many relics of the former kingdom of Silla is still maintained. Although it’s of a very old age, the Cheomseongdae observatory still stands and has became the national cultural heritage of Korea.
The stone structure of the Cheomseongdae building is quite unique. It’s made up of a square shaped base section which consists of 12 blocks of stone. This arrangement was made up of 2 layers with the second layer buried in the ground. The main part of the building is shaped like a bottle. The cylindrical tower has a base circumference greater than the circumference of the top. It’s made up of stone composition totaling 365 pieces. The main part consists of 27 layers. In the middle there is a square window facing north. The number of layers above and below the window amounts to 12 layers. The top is made of two layers of fences. The number 12 represents the number of months in a year. While the number 365 is the number of days in a year.
According to Japanese astrologers, one being Yuji Wada, who did research on the site since 1909, believes that this place was the observatory that was used by royal Silla astronomers to observe the movement of stars and planets, as well as to predict solar and lunar eclipses. Most of the observations at this observatory used the naked eye and/or simple tools such as the gnomon to calculate the movement of the sun.
In 1982, after some research, the Cheomseongdae in Gyeongju was declared as one of the world’s oldest observatory buildings that are still standing today.