Old book illustrates 15th-century astronomical study in Korea

From olden times, the Korean nation has achieved signal successes in the astronomical field.

It is also evidenced by Kyosikthonggwe, an astronomical book on the system of calculating the solar and lunar eclipses.

This one-volume printed book was published in 1444.

The first part of the book tells about the method of calculating the number of days the moon takes to move to the intersecting point between the ecliptic and the moon’s orbit from the end of the month and the next part introduces the theory on solar eclipse. And the last part deals with the method of calculating lunar eclipse.

The methods of predicting solar and lunar eclipses were applied until 1652.

Kyosikthonggwe, which was based on scientific observation in many aspects, is a precious history book showing Korea's astronomical developments in the 15th century.