understanding of astrology. Kings, in fact, restricted such
study to scholars under royal employment, in hopes of main-
taining a sure hold on power that was oft en secured through
accurate predictions. Into medieval times ordinary citizens
were punished for possessing or using objects associated with
the measurement of celestial bodies or with divination based
on such measurements. Th e importance ascribed to the study
of astronomy is refl ected in the fact that the Chinese record-
ed a number of observations before either the Greeks or the
Babylonians.
In general, the ancient Chinese classifi ed astronomical
events into two categories: predictable and unpredictable.
Predictable events included the shift ing of the phases of the
moon and the rotation of the constellations around the North
Star. Unpredictable events of particular note included the
wandering of the planets (whose orbits were long undeter-
mined in geometric terms), the appearance of comets, and
instances of sunspots, which were especially observable when
dust storms in northern China screened the sun’s glare. A
great deal of attention was paid to these unpredictable events,
which wise men, particularly those in the service of rulers,
interpreted in order to extract cosmic meaning.
Knowledge regarding predictable events, then, was val-
ued largely for its providing the frame of reference against
which unpredictable events occurred. Th e origins of an impe-
rial almanac, which served as a register of these predictable
events, are so ancient as to be obscure. Th e almanac delin-
eated the annual astronomical cycle, including the lengths
of the months (which were based on the phases of the moon
and thus varied from year to year) and the dates of the equi-
noxes (the two times of the year at which the sun crosses the
equator and day and night are of relatively equal length) and
solstices (the times of year when the sun is at the greatest dis-
tance from the equator and the day is either at its shortest or
at its longest, depending on the season). Th e year began at
the winter solstice, when the yang force—a Chinese concep-
tion associated with warmth, among other qualities—was at
its nadir. Since the winter solstice oft en proved to be a cloudy
day, its date was calculated based on that of the summer sol-
stice, which was determined through the measurement of the
shadow of an 8-foot stone pillar. Th e length of the year was
estimated to be 366 days until the fourth century b.c.e., when
the fi gure was revised to 365¼ days; further corrections were
made continually thereaft er.
According to legend, basic star charts were fi rst compiled
sometime before 1000 b.c.e. by a shaman named Xian, who
identifi ed the Big Dipper, among other constellations. Th e
revolution and rotation of the Big Dipper around the North
Star, rather than the movement of the sun, provided the ba-
sis for many Chinese astronomical computations. Records
still exist of the star charts compiled in the fourth century
b.c.e. by the early astronomical observers Shi Shen and Gan
De—whereas charts compiled by Timocharis (ca. 320– 260
b.c.e.), of Greece, have never been found. Much later, in the
fi ft h century c.e., Qian Lezhi incorporated the fi ndings of his
Covered jar, from the second to fi rst century b.c.e., China; the scene is
of a blue beast (the star Sirius) with bared fangs lunging at a mounted
archer (the adjoining constellation, Bow). (Copyright the Metropolitan
Museum of Art)128 astronomy: Asia and the Pacificthree regional predecessors into a single chart, coding their
fi ndings with the colors white, red, and black.
Comets, eclipses, and supernovae (explosions of stars)
were seen as especially momentous astronomical occurrenc-
es. Records of comets are more extensive in China than in
anywhere else in the ancient world, and these records pro-
vided the original basis for determining the orbit of Halley’s
comet, which was sighted in China fi rst, in 240 b.c.e. Records
of eclipses extend back even further in time, as inscriptions
were fou nd on oracle bones— a ni ma l bones t hat were used for
divination—dating back to the Shang Dynasty, which ended
around 1045 b.c.e. Th us, Chinese records predate Babylonian
ones by some seven centuries. Starting in the third century
b.c.e. eclipses were carefully registered. Supernovae, which
are stellar explosions that can make distant stars visible to the
naked eye for the fi rst time, were referred to as inexplicable
new stars or stranger stars.
Th e Chinese made a number of advances in the design
of astronomical equipment. Th e Han Dynasty, which lasted
from the second century b.c.e. to the second century c.e.,
witnessed the invention of a star-mapping tool called the ar-
millary sphere, a fi xed set of rings demarcating the sectors of
the sky. Th e ring representing the skyward extension of the