asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
from the outer regions of the
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
. It was discovered on 30 October 1957, by astronomer Zhāng Yùzhé (Y. C. Chang，张钰哲) at the Chinese
Purple Mountain Observatory
The Purple Mountain Observatory (), also known as Zijinshan Astronomical Observatory is an astronomical observatory located on the Purple Mountain in the east of Nanjing.
Description
The Purple Mountain Observatory was established in 1934 fun ...
（紫金山天文台） in Nanjing, and named in honor of the country
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. The assumed
C-type asteroid
C-type (carbonaceous) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...
has a short
rotation period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...
of 5.4 hours and measures approximately in diameter. Its name and number were actually taken from another asteroid that was considered a
lost asteroid
A minor planet is "lost" when today's observers cannot find it, because its location is too uncertain to target observations. This happens if the orbital elements of a minor planet are not known accurately enough, typically because the observat ...
at the time, but was eventually rediscovered and given the new designation
3789 Zhongguo
3789 Zhongguo, provisional designation ', is a resonant asteroid from outermost region of the asteroid belt, approximately in diameter. It was discovered in 1928 by Chinese astronomer Zhang Yuzhe at the Yerkes Observatory in Williams Bay, Wisco ...
. "Zhongguo" means "China" in Chinese ().
Orbit and classification
''China'' is a non-
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
hierarchical clustering method
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An a ...
to its
proper orbital elements
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The proper orbital elements or proper elements of an orbit are constants of motion of an object in space that remain practically unchanged over an astronomically long timescale. The term is usually used to describe the three quantitie ...
Raoul Behrend
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...