Peering through time, what secrets does Gwancheondae Observatory hold? Gwancheondae Observatory stands as a testament to Korea’s rich astronomical history. It offers us a peek into the cosmos as seen by the Silla Dynasty.
The Silla Dynasty queen, who ruled Korea in the latter half of the 7th century, couldn’t have fathomed today’s modern advancements. She certainly never envisioned high-speed trains whisking people near Gyeongju. Yet, here we stand, not far from the ancient capital. This area was the heart of the Silla Dynasty, which reigned from 57 B.C. to 935 A.D.
From a distance, Gwancheondae Observatory’s size may seem modest. But approach closer and its construction impresses. Cut rectangular stones are stacked precisely to form a tapered tower. The stones are about the length from hand to elbow and the height from hand to wrist.
Historian Sang-Woon Jeon noted the observatory’s peculiar shape. It aligns with the Chinese theory of round-heaven, square-earth. The tower’s 27 layers of fan-shaped stones likely symbolize Queen Seondeok. She was the twenty-seventh Silla monarch.
A square window sits midway up the side, facing south. This served as the access point, probably via a ladder. Observations happened at the top of Gwancheondae Observatory. Observers likely used an armillary instrument, a model showing celestial positions.
Ancient Koreans were certainly interested in the sky. A 1395 Joseon Dynasty chart, engraved in stone, maps over 1467 stars. It is the world’s second oldest surviving astronomical chart. Unlike Chinese charts, this Korean chart marks the stars in different sizes. This shows that ancient Koreans recognized that star diameters are not uniform.
In Korea, sky phenomena guided political and societal matters. Queen Seondeok sought spiritual guidance from the sky. Gwancheondae Observatory even spotted at least 29 comets. These were seen as harbingers of catastrophic events. Records show many astronomical observations from the Silla Dynasty. These include solar and lunar eclipses, supernovae, and comets.
Gwancheondae Observatory has retained its original appearance for about 1300 years. The structure is slightly tilted to the north-east but the original shape remains mostly intact.
Today, Gwancheondae Observatory stands near modern conveniences. Yet, it’s easy to imagine climbing this tower on a clear night. Imagine looking out in awe at a passing comet or a “guest star.” Picture an ancient planetary conjunction of Venus and Mars. Queen Seondeok had this curious tower constructed, inspiring us even today. Ancient Korea was technologically curious. It was interested in all things celestial.