A lunar impact crater has been named after Nam Byeong-Cheol, a renowned astronomer and mathematician in the late Joseon period

The Danuri Magnetic Field Payload Research Team (Director: Professor Jin Ho) at the School of Space Research applied to the International Astronomical Union (IAU) to name a previously unnamed crater, located on the far side of the Moon and exhibiting unique magnetic characteristics, after Nam Byeong-Cheol. Following a final review, on August 14, 2024, the IAU officially designated the crater as the “Nam Byeong-Cheol” crater (Feature ID: 16337).

This marks the first time that a surface feature on the Moon has been named after a Korean historic figure. The Nam Byeong-Cheol crater is also the largest crater to be named since 1980. To date, a total of 1,659 lunar surface craters have been named.

Naming a lunar impact crater: scientific significance of the object and the verifiable scientific achievements of the eponym are both important
In a joint study with Professor Ian Garrick-Bethell of the University of California, Santa Cruz, the Kyung Hee University Danuri Magnetic Field Payload Research Team discovered that this impact crater had not yet been named and subsequently applied for its designation. The name “Nam Byeong-Cheol” was decided in consultation with the Korea Astronomy and Space Science Institute's Center for Ancient Astronomy. The naming of planetary objects and features is overseen by the IAU, which requires that the scientific significance of the object be clearly demonstrated. Additionally, the scientific contributions of the eponym, the individual after whom the feature is named, must also be substantiated with verifiable evidence.

The Nam Byeong-Cheol crater was one of several impact craters examined by the research team while studying magnetic field variations of the lunar surface caused by the impact energy of crater formation. The research team collaborated with the University of California, Santa Cruz, to organize and submit their findings. The background and scientific significance of Nam Byeong-Cheol (1817-1863) as an astronomer and mathematician was validated through reference materials published in the Journal of Astronomy and Space Sciences (JASS), the official publication of the Korean Space Science Society (KSSS).

The Nam Byeong-Cheol crater has a diameter of 132km and is located on the far side of the Moon. Like the nearby Houzeau crater, it exhibits variations in magnetic signatures inside and outside the crater. Before formal naming, the scientific data on the Nam Byeong-Cheol crater was published in the journal Nature, where the crater was referenced without its name.

Nam Byeong-Cheol, the eponym of the crater, was a high-ranking civil servant during the late Joseon Dynasty, holding such positions as Yejo Panseo (예조판서; Minister of Rites), Yijo Panseo (이조판서; Minister of Interior), and Daejehak (대제학; President of Royal Academy). Distinguished in mathematics and astronomy, he constructed several important devices, including a water wheel, an armillary sphere, and a four-season clock. His scholarly publications include Haegyeongsechohae (해경세초해; 海鏡細草解), Uigijipseol (의기집설; 儀己輯說), Seongyo (성요; 星要), Chubosokhae (추보속해; 推步續解), and Gyujaeyugo (규재유고; 圭齋遺稿).

It is anticipated that the Korean lunar orbiter Danuri, launched in August 2022, will conduct additional observations of the Nam Byeong-Cheol crater during its low altitude mission, potentially leading to new discoveries and further research.