16.5 degrees clockwise from the cardinal directions, lining
up with certain mountain peaks that could have been used as
natural markers of sunrises and sunsets on signifi cant dates.
Th ese dates were necessary for predicting important seasonal
changes and for effi ciently scheduling corresponding agri-
cultural activity. For example, in the fi rst century c.e. these
alignments would have recorded sunrises on Februar y 11 and
October 29 and sunsets on April 30 and August 13. Th e in-
tervals from February 11 to October 29 and from August 13
to April 30 are exactly 260 days, again coinciding with the
260-day sacred calendar. Th e 260-day period is also tied to
the human gestation period, the time from the fi rst missed
menstrual fl ow to birth, thereby connecting the functional
aspect of the calendar to the birth cycle as well as to agricul-
ture, ritual, and urban planning.
Th e astronomical record for North and South America
in the ancient period suff ers from a lack of hard data. Data
for later periods are much more convincing. Some evidence
does suggest, however, that ancient North American mound
builders used the star group Pleiades as a celestial template for
particular clusters of conical mounds in the Midwest, such as
burial mounds and earthworks at Poverty Point, Louisiana
(1600–1300 b.c.e.); Adena burial mounds in Ohio, Kentucky,
and West Virginia (1000 b.c.e.–200 c.e.); and Hopewell
mounds in southern Ohio (200 b.c.e.–400 c.e.). Th e Pleiades
were important, especially in northeastern North American
latitudes, because their horizon cycle corresponds to the lim-
its of the frost-free zone and thus helped defi ne the growing
season once agriculture became common.
Th e medicine wheels left by the nomadic Indians of
the Great Plains are thought to have astronomical signifi -
cance, though the exact use is unclear. Medicine wheels are
enigmatic large patterns of linear stone alignments, many
of which have the appearance of a spoked wheel. Oft en the
spokes, or rays, point to the horizon and mark points of the
summer solstice sunrise, the winter solstice sunrise, or the
rise of the star Sirius. Various examined sites, such as those
at Majorville in Alberta, Canada, and Moose Mountain in
Saskatchewan, show evidence of use dating back to 2500
b.c. Many of the medicine wheels are thought to exist from
later periods.
In South America a clearer data record exists for the
Inca (1438–1534 c.e.) than it does for earlier cultures, such
as those at Chavín de Huántar (900–200 b.c.e.), Paracas
(600–175 b.c.e.), and Nazca (1–700 c.e.). Th e most suggestive
early astronomical possibility comes from the Nazca culture,
which created the Nazca Lines with some possible astronomi-
cal signifi cance in mind. Shaman imagery on textiles from
the Paracas culture suggests at least an affi nity for connect-
ing the earth and the heavens through visual iconography,
or symbolism. Architectural remains at Chavín de Huántar
show a solar east-west axis that confl ates architecture, hu-
man ritual, and cosmological associations. A corresponding
north-south axis is suspected, thereby symbolizing all four
cardinal directions. More research needs to be undertaken
to establish a clearer record for the relationship of astronomy
to these sites.See also agriculture; architecture; calendars and
clocks; cities; climate and geography; death and
burial practices; hunting, fishing, and gathering; in-
ventions; literature; numbers and counting; religion
and cosmology; sacred sites; science; seafaring and
navigation; weights and measures; writing.First located in the 1920s from aerial reconnaissance,
the Nazca Lines have prompted debate, speculation,
and confusion over what exactly they represent. Cre-
ated by the Nazca culture (1–700 C.E.) across a 130-
square-mile swath of desert tableland on the central
Peruvian coast, the lines are made by displacing dark
stones from atop lighter ones. Created over many
hundreds of years, the more than 1,000 miles of lines
consist of overlapping, radiating lines and trapezoids
and immense fi gures of animals, humans, plants, and
objects (including a monkey, a dog, a killer whale,
lizards, birds, a tuber, geometric fi gures, and even
a fantastic fi gure often referred to as the Martian).
The span of a hummingbird image is greater than
the length of fi ve jumbo jets. One line goes perfectly
straight for 13 miles.
Theories have linked the lines to pilgrimages,
water rituals, astronomical alignment, ceremonial
walkways, and religious activity tied to ensuring
a good harvest. Modeling the lines with the aid of
computerized mapping in reference to celestial posi-
tioning has shown that twice as many astronomical
alignments show up than would be expected from
pure chance. Furthermore, prominent archaeoas-
tronomists (scholars who combine astronomy and
archaeology to study ancient civilizations) have used
computer analysis to show that many lines point to
the sun’s position on the horizon during the time of
year when the rains begin.
The immensity of the lines prevents them from
being viewable on the ground, automatically orient-
ing them to the celestial world above, where a sha-
man, or holy man, in bird form might have been the
intended audience. Although their overall meaning is
still debated, most theories involve the idea of repeat-
ed ritual action. Where some of the rituals are tied
to water and thus to agriculture and seasons, simply
by raising one’s head one connects the lines at one’s
feet to the horizon and eventually to the rising sun
and stars.THE NAZCA LINES
134 astronomy: The Americas