Purple Mountain Observatory, also known as Zijinshan Astronomical Observatory, is a dual-use astronomical observatory operated by the Chinese Academy of Sciences (CAS) and the People's Liberation Army Aerospace Force (PLAASF). It is headquartered at Purple Mountain, east of Nanjing, with off-site sensor installations located across the country. The observatory has a very active open science role, serving as China's primary contribution to the Inter-Agency Space Debris Coordination Committee, global asteroid impact avoidance efforts, and calculating the official Chinese calendar. Since the early 2000s, the observatory has gained a significant classified intelligence role, serving as China's primary optical space domain awareness capability. At least part of the military component is operated by PLAASF Base26 as the Space Target and Debris Observation and Research Center.

History

The Purple Mountain Observatory was established in 1934 funded by the Nationalist Government of the Republic of China and administered by Academia Sinica. The longtime director of the observatory from 1950 to 1984 was Chinese astronomer Zhang Yuzhe. By the late 1980s, increasing light pollution in Nanjing meant Purple Mountain was no longer viable as a working observatory. It has since shifted its focus to public education, with much of the actual scientific work being carried out in its five branch observatories located at Qinghai (in Delingha), Ganyu, Xuyi, Honghe (in Jiamusi), and Qingdao.

The Minor Planet Center credits the observatory with the discovery of 149 minor planets between 1955 and 1983, while the observatory's PMO NEO Survey Program is credited with more than 600 discoveries between 2006 and 2013.

In August 2026, it was reported that the New Zealand Security Intelligence Service disrupted a plan by Purple Mountain Observatory to install ground-based space infrastructure in New Zealand that could collect intelligence of military value.

Discoveries

The observatory discovered the periodic comets 60P/Tsuchinshan and 62P/Tsuchinshan, as well as the non-periodic (Tsuchinshan), also known as Comet 1977 X, , and C/2023 A3 (Tsuchinshan-ATLAS). They are named after the postal romanization of the name (Wade–Giles: Tzu-chin-shan; pinyin: Zǐjīnshān). Many asteroids were also discovered, including the Trojan asteroids 2223 Sarpedon, 2260 Neoptolemus, 2363 Cebriones, 2456 Palamedes, and the eponymous 3494 Purple Mountain.

Near-Earth object survey

The Chinese Near-Earth Object Survey (CNEOS), based at the Xuyi Station in Xuyi, Jiangsu, started observations in 2006. It uses a 1:04=1:20=1:80 m Schmidt telescope equipped with a 4K × 4K CCD detector with the drift-scanning function. As of August 2012, the program has observed 149,971 asteroids, found 1,279 new provisional designation asteroids, and cataloged 251 numbered asteroids including five Jupiter trojans, two Hildian, and one Phocaea asteroid. The program has also observed the position of 824 near-Earth objects (NEOs) and discovered four new ones: the Apollo asteroid , and the three Amor asteroid , , and .

List of discovered minor planets (1955–1983) + Minor planets discovered: 149 see

A total of 149 minor planets were discovered by the Purple Mountain Observatory between 1955 and 1983.

1125 China 30 October 1957 1802 Zhang Heng 9 October 1964 1888 Zu Chong-Zhi 9 November 1964 1972 Yi Xing 9 November 1964 2012 Guo Shou-Jing 9 October 1964 2027 Shen Guo 9 November 1964 2045 Peking 8 October 1964 2077 Kiangsu 18 December 1974 2078 Nanking 12 January 1975 2085 Henan 20 December 1965 2162 Anhui 30 January 1966 2169 Taiwan 9 November 1964 2184 Fujian 9 October 1964 2185 Guangdong 20 November 1965 2197 Shanghai 30 December 1965 2209 Tianjin 28 October 1978 2215 Sichuan 12 November 1964 2223 Sarpedon 4 October 1977 2230 Yunnan 29 October 1978 2255 Qinghai 3 November 1977 2260 Neoptolemus 26 November 1975 2263 Shaanxi 30 October 1978 2336 Xinjiang 26 November 1975 2344 Xizang 27 September 1979 2355 Nei Monggol 30 October 1978 2363 Cebriones 4 October 1977 2380 Heilongjiang 18 September 1965 2387 Xi'an 17 March 1975 2398 Jilin 24 October 1965 2425 Shenzhen 17 March 1975 2456 Palamedes 30 January 1966 2503 Liaoning 16 October 1965 2505 Hebei 31 October 1975 2510 Shandong 10 October 1979 2514 Taiyuan 8 October 1964 2515 Gansu 9 October 1964 2539 Ningxia 8 October 1964 2547 Hubei 9 October 1964 2592 Hunan 30 January 1966 2617 Jiangxi 26 November 1975 2631 Zhejiang 7 October 1980 2632 Guizhou 6 November 1980 2655 Guangxi 14 December 1974 2693 Yan'an 3 November 1977 2719 Suzhou 22 September 1965 2729 Urumqi 18 October 1979 2743 Chengdu 21 November 1965 2752 Wu Chien-Shiung 20 September 1965 2778 Tangshan 14 December 1979 2789 Foshan 6 December 1956 2790 Needham 19 October 1965 2851 Harbin 30 October 1978 2886 Tinkaping 20 December 1965 2899 Runrun Shaw 8 October 1964 2903 Zhuhai 23 October 1981 2963 Chen Jiageng 9 November 1964 3011 Chongqing 26 November 1978 3014 Huangsushu 11 October 1979 3024 Hainan 23 October 1981 3028 Zhangguoxi 9 October 1978 3048 Guangzhou 8 October 1964 3051 Nantong 19 December 1974 3088 Jinxiuzhonghua 24 October 1981 3089 Oujianquan 3 December 1981 3136 Anshan 18 November 1981 3139 Shantou 11 November 1980 3171 Wangshouguan 19 November 1979 3187 Dalian 10 October 1977 3206 Wuhan 13 November 1980 3221 Changshi 2 December 1981 3239 Meizhou 29 October 1978 3241 Yeshuhua 28 November 1978 3297 Hong Kong 26 November 1978 3335 Quanzhou 1 January 1966 3340 Yinhai 12 October 1979 3388 Tsanghinchi 21 December 1981 3405 Daiwensai 30 October 1964 3421 Yangchenning 26 November 1975 3443 Leetsungdao 26 September 1979 3462 Zhouguangzhao 25 October 1981 3463 Kaokuen 3 December 1981 3476 Dongguan 28 October 1978 3494 Purple Mountain 7 December 1980 3502 Huangpu 9 October 1964 3509 Sanshui 28 October 1978 3513 Quqinyue 16 October 1965 3542 Tanjiazhen 9 October 1964 3543 Ningbo 11 November 1964 3556 Lixiaohua 30 October 1964 3560 Chenqian 3 September 1980 3570 Wuyeesun 14 December 1979 3609 Liloketai 13 November 1980 3611 Dabu 20 December 1981 3613 Kunlun 10 November 1982 3643 Tienchanglin 29 October 1978 3650 Kunming 30 October 1978 3678 Mongmanwai 20 January 1966 3704 Gaoshiqi 20 December 1981 3729 Yangzhou 1 November 1983 3746 Heyuan 8 October 1964 3763 Qianxuesen 14 October 1980 3812 Lidaksum 11 January 1965 3844 Lujiaxi 30 January 1966 3901 Nanjingdaxue 7 April 1958 3960 Chaliubieju 20 January 1955 4047 Chang'E 8 October 1964 4073 Ruianzhongxue 23 October 1981 4245 Nairc 29 October 1981 4273 Dunhuang 29 October 1978 4360 Xuyi 9 October 1964 4431 Holeungholee 28 November 1978 4562 Poleungkuk 21 October 1979 4566 Chaokuangpiu 27 November 1981 4651 Wongkwancheng 31 October 1957 4730 Xingmingzhou 7 December 1980 4913 Wangxuan 20 September 1965 4925 Zhoushan 3 December 1981 4988 Chushuho 6 November 1980 5013 Suzhousanzhong 9 November 1964 5045 Hoyin 29 October 1978 5198 Fongyunwah 16 January 1975 5217 Chaozhou 13 February 1966 5267 Zegmott 13 February 1966 5273 Peilisheng 16 February 1982 5389 Choikaiyau 29 October 1981 5390 Huichiming 19 December 1981 5537 Sanya 9 October 1964 5538 Luichewoo 9 October 1964 5539 Limporyen 16 October 1965 5709 Tamyeunleung 12 October 1977 5892 Milesdavis 23 December 1981 6 November 1980 30 October 1964 7811 Zhaojiuzhang 23 February 1982 3 December 1981 8126 Chanwainam 20 January 1966 8256 Shenzhou 25 October 1981 31 December 1964 8992 Magnanimity 14 October 1980 9512 Feijunlong 13 February 1966 9517 Niehaisheng 3 November 1977 9 November 1964 10017 Jaotsungi 30 October 1978 7 December 1980 14 December 1974 9 November 1964 14 October 1980 11 November 1964 23408 Beijingaoyun 12 October 1977

List of discoveries by the PMO NEO Survey Program + PMO NEO Survey discoveries: 646 see

Several hundred minor planets were discovered by the observatory's PMO NEO Survey Program from 2006 to 2013.

18 August 2007 171448 Guchaohao 11 September 2007 175633 Yaoan 9 October 2007 185535 Gangda 28 November 2007 185538 Fangcheng 14 December 2007 185640 Sunyisui 1 March 2008 187707 Nandaxianlin 2 March 2008 187709 Fengduan 3 March 2008 188973 Siufaiwing 3 March 2008 192178 Lijieshou 10 March 2007 199947 Qaidam 16 April 2007 199953 Mingnaiben 18 April 2007 200002 Hehe 6 May 2007 200003 Aokeda 19 May 2007 202784 Gangkeda 29 February 2008 204836 Xiexiaosi 16 August 2007 204839 Suzhouyuanlin 16 August 2007 207681 Caiqiao 16 August 2007 207715 Muqinshuijiao 11 September 2007 207716 Wangxichan 11 September 2007 207723 Jiansanjiang 11 September 2007 17 September 2007 207809 Wuzuze 9 October 2007 210210 Songjian 16 August 2007 210230 Linyuanpei 11 September 2007 210231 Wangdemin 11 September 2007 210232 Zhangjinqiu 11 September 2007 210292 Mayongsheng 6 October 2007 12 August 2007 212795 Fangjiancheng 9 October 2007 212796 Guoyonghuai 9 October 2007 212797 Lipei 9 October 2007 11 September 2007 214883 Yuanxikun 11 September 2007 26 January 2009 27 January 2009 10 October 2007 5 November 2007 25 March 2009 19 May 2007 16 May 2007 16 August 2007 19 September 2009 7 May 2007 229864 Sichouzhilu 14 October 2009 10 April 2007 16 August 2007 9 August 2007 11 September 2007 20 August 2007 11 September 2007 11 September 2007 6 October 2007 5 October 2007 30 December 2008 16 August 2007 21 September 2007 8 October 2007 19 December 2006 11 September 2007 6 October 2007 9 November 2007 26 January 2009 14 October 2009 14 October 2009 16 August 2007 11 September 2007 11 September 2007 17 October 2007 6 November 2007 11 November 2007 18 January 2009 11 September 2007 4 November 2007 24 January 2009 26 January 2009 24 January 2009 27 January 2009 29 April 2009 8 April 2010 3 March 2008 14 March 2008 18 January 2009 6 October 2007 9 October 2007 6 February 2008 19 August 2010 5 November 2007 29 February 2008 29 February 2008 28 February 2008 29 February 2008 2 March 2008 2 March 2008 2 March 2008 4 March 2008 23 March 2009 2 May 2009 18 September 2009 16 April 2007 14 October 2009 23 November 2009 24 November 2009 12 May 2007 16 May 2007 5 October 2007 5 November 2007 29 February 2008 13 September 2009 16 August 2007 9 October 2007 9 October 2007 3 March 2008 24 January 2009 16 March 2009 24 November 2009 10 March 2010 16 August 2007 6 October 2007 8 November 2007 1 January 2009 19 August 2010 16 May 2007 6 May 2007 12 May 2007 11 September 2007 11 September 2007 4 October 2007 16 October 2007 14 December 2007 23 January 2009 19 March 2010 3 April 2010 16 April 2007 7 May 2007 6 May 2007 12 August 2007 12 August 2007 16 August 2007 16 August 2007 11 September 2007 11 September 2007 11 September 2007 11 September 2007 2 November 2007 2 November 2007 5 November 2007 5 January 2008 3 March 2008 2 January 2009 24 January 2009 26 January 2009 24 January 2009 27 January 2009 24 January 2009 26 January 2009 27 January 2009 26 January 2009 16 March 2009 16 March 2009 2 May 2009 13 September 2009 18 September 2009 24 October 2009 10 March 2010 29 February 2008 21 September 2007 6 October 2007 9 October 2007 4 October 2007 6 October 2007 5 November 2007 5 November 2007 6 November 2007 4 January 2008 26 January 2009 27 January 2009 23 January 2009 25 March 2009 23 March 2009 8 April 2010 18 August 2007 11 September 2007 11 September 2007 6 November 2007 6 November 2007 28 November 2007 14 December 2007 5 January 2008 5 January 2008 29 February 2008 29 February 2008 26 January 2009 26 January 2009 26 January 2009 27 April 2009 10 March 2007 11 September 2007 11 September 2007 16 August 2007 11 September 2007 2 November 2007 3 March 2008 24 January 2009 10 August 2010 10 April 2007 11 September 2007 11 September 2007 9 October 2007 10 October 2007 2 November 2007 4 February 2008 2 March 2008 4 March 2008 27 January 2009 16 March 2009 25 March 2009 27 April 2009 26 April 2009 18 August 2010 12 August 2007 11 September 2007 5 November 2007 14 December 2007 29 February 2008