PlanetQuest: The History of Astronomy
Pacific Island Voyagers
|Click on the map to see it in greater detail. (Map courtesy of the Central
Intelligence Agency World Factbook 2004.)
Draw a line from Hawai'i southeast to Pitcairn Island,
made famous by the mutineers of The Bounty; draw a second line southwest from
Pitcairn to New Zealand; draw a third line from New Zealand northwest to the
Philippines, avoiding Australia as you go; and finally draw a fourth line from
the Philippines back to Hawai'i. This rather sloppy rectangle encloses the thousands
of islands known loosely as the Pacific Islands. More specifically it marks
off three geographic regions: Polynesia (the sweeping southeastern side of the
rectangle), Melanesia (including New Guinea and islands to the east), and Micronesia
(islands to the north and east of New Guinea).
Anthropologists have known for some time that the first human inhabitants of
many of these islands had arrived by at least 1500 BC, apparently originating
from New Guinea and its surrounding islands. But this raises an interesting
question. Given that the magnetic compass would not be invented for at least
another 2000 years, how did the early people of this region manage to make their
way from one island to another without getting lost?
Swayed perhaps by the fact that European voyagers had from the beginning been
dependent upon the compass, researchers used to believe that these early island
journeys were basically accidents. The Pacific voyagers set sail into the unknown,
and if they were lucky stumbled across an island and settled there. However,
more recent discoveries have made it clear that these trips were anything but
accidental, that these early people possessed remarkable navigational skills,
and moreover that these ancient skills are still in use today.
The techniques employed by modern ppalu—navigators trained in the traditional
skills—have been shown to date back at least 4000 years. They make
use of a complete understanding of the ocean's movements and appearances—its
currents, swells, colors, winds, temperature variations, even its birds—to
recognize the cardinal directions north, south, east and west; to pinpoint islands
before they can be seen; and to generally keep track of one's place in
the seemingly featureless, directionless expanse of the open seas. They also
make use of a considerable knowledge of astronomy.
|As Earth rotates, the stars appear to move through the sky, rising and
eventually setting at the same point on the horizon each night. (Photo by
Carlos Milovic, courtesy of the European Southern Observatory.)
Although the specific astronomical techniques used by ancient island mariners
varied somewhat from place to place, there appears to have been a remarkable
degree of similarity across the entire region. One common technique utilized
the points along the horizon where particular stars rise and set. Because all
day-to-day motion in the sky is due to the Earth's
rotation, the stars appear to rise in the east, travel across the sky, and
set in the west each night just as the Sun does each day. Unlike the Sun, however,
the stars rise and set at exactly the same point on the horizon every day, year
after year. (There is a small shift that builds up over hundreds and thousands
of years due to Earth's precession,
but this would not be noticeable in a navigator's own lifetime.) However, the
time of night when a star rises or sets will change throughout the year due
to Earth's orbit.
To see how this navigational method works, imagine that you are on your home
island and you wish to sail in some direction—shall we say 32 deg. north of
east?—to another island, your destination island. How do you do this?
Well, first you consider the time of year and use your knowledge of the sky
to tell you which star will be rising 32 deg. north of east when the Sun is just
setting. Then, as the Sun sets and the stars begin to appear, you find your
guide star on the horizon and steer your course accordingly.
Of course as the night wears on, Earth's rotation will slowly lift your
guide star higher and higher in the sky, so that in an hour or two it will be
too far above the horizon to be a useful guide. However, your knowledge of astronomy
tells you that by that time, another star will be rising up from the same place
on the horizon, following your first guide star. You therefore begin watching
for this second star, and as soon as it appears, it becomes your new guide star.
Then, by the time this second star has risen too high, a third guide star will
be rising from the same place, and so on.
By following this chain of stars, all of which rise from the same point on the
horizon—a chain of stars known as a kavenga (or kaveinga, depending on
the local language)—you can stay on course throughout the night. Ancient
navigators had to memorize a different kavenga for each of many distinct directions
on the horizon, and of course they had to be able to recognize every star in
each kavenga wherever it was in the sky, at whatever time of year.
This idea of the kavenga, also known as a star path, is closely related to
the star compass. A star compass uses a circle to represent the horizon, much
like a modern compass does, but instead of being marked with only the cardinal
directions, the star compass is marked with the names of stars that rise at
various points. Although the particular stars that were used vary from place
to place, some form of star compass appears to have been used by numerous cultures
across the South Pacific.
Another navigational technique utilized what is known as an etak. An etak is
an island that you use as a reference point on your journey. Let's say
you are voyaging from your home island to some destination island. Your etak,
or reference island, would lie somewhere between your home and your destination,
but off to the side some distance. As a skilled navigator, you would already
have chosen this etak island in advance. You would also know a series of stars
that would appear successively above the etak as you proceed along your course.
When the etak island appears to have moved from one star to the next, your boat
will have moved a distance referred to as one "etak." This distance
will vary somewhat throughout your journey, since the stars are not evenly spaced,
but the etak island and the stars will have been chosen in such a way that one
"etak" of distance is around 20 miles.
David Lewis, who deserves much of the credit for drawing the world's
attention to the methods of Pacific Island navigators, mentions in his book
The Voyaging Stars the following conversation that he had with Hipour,
a modern day navigator:
Hipour collected together an assortment of miscellaneous objects, including
a pocket knife, some fishhooks and a few coins.
"Here is your canoe." He pointed to the knife. "These fishhooks
are three islands, the one you are leaving, the one you are bound for and,
away out at right angles to your course, the etak or reference island. The
coins are the star compass points.
"From your home island the etak island lies 'under' Antares.
[I have substituted the Western star names.] By the time your canoe
is here"—he shifted the knife to point B—"the etak
island has 'moved' to the star point Aldebaran. When you reach
your goal the etak island has 'moved' further back still. Now
it is 'under' the Pleiades.
"All the while you will be judging in your mind how far back your etak
island has moved. Each star point that it moves back means that you have progressed
Using these and other clever yet straightforward methods, ocean voyagers of
the South Pacific—both ancient and present day—have journeyed not
only the hundreds of miles between neighboring islands, but even the thousands
of miles that separate Hawai'i from the islands of southern Polynesia,
Micronesia, and Melanesia. In this high–tech age, many people would find
it incredible that anyone could navigate such distances with nothing but the
stars and a knowledge of the sea. But quoting the modern day canoe captain Ve'etutu
Pahulu, "I did have a compass once, but I gave it away. The star path—kaveinga—is
more to be trusted than any compass."†
Return to Index
* David Lewis, The Voyaging Stars: Secrets of the Pacific Island Navigators, Norton & Company, New York, 1978, p. 145.
† Ibid., p. 75.
Lewis, David, The Voyaging Stars: Secrets of the Pacific Island Navigators,
Norton & Company, New York, 1978.
Wayfinders: A Pacific
Other useful links and references:
Kelley, David H., and Eugene F. Milone, Exploring Ancient Skies: An Encyclopedic
Survey of Archaeoastronomy, Springer, New York, 2005.
Lewis, David, We, The Navigators: The Ancient Art of Landfinding in the
Pacific, University of Hawaii Press, Honolulu, 1975.