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 Base 26 as the Space Target and Debris Observation and Research Center.

Description

thumb|left|200px|The 60-cm Zeiss reflector at Nanking in 1930

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. 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 .

<!-- end of reflist -->

  • Purple Mountain Observatory website