by Joan Marie Galat
The oldest known map was written on
a Babylonian clay tablet in about 2300 BC. People have appreciated how
knowledge can be conveyed through maps for a very long time! Early diagrams on
paper were drawn by hand but before mass production was possible, most people needed
other methods to find their way around. Verbal directions, landmarks, and an
understanding of landscape were vital. Knowledgeable desert travellers used, and
still use, the shape of sand dunes to determine direction based on predominant
wind patterns.
For centuries, explorers and other
travellers have depended on the Sun, Moon, and stars to gather navigation
information. While it has become the norm in North America and many other parts
of the world to use global positioning system (GPS) technology, satellite
images, and other technologies to find directions, it’s still useful to know one
of the basics—how to find the North Star.
Named Polaris,
the North Star is part of the Little Dipper, also called Ursa Minor. Although it’s
an important star, it’s not the biggest or brightest star in our night sky. If
you could visit the North Pole, lay on your back, and look straight up, Polaris
would be the star you see nearly directly overhead.
Try to
find Polaris on a dark, clear night. Begin by giving your eyes 30—45 minutes to
adjust to the dark. Face north and make two fists, tucking your thumbs to one
side instead of overtop your index fingers. To find the North Star, stretch
your arm straight out in front of you and place one fist atop the other. Now
repeat this maneuver, going hand-over-hand the same number of degrees as your
latitude. You can find your latitude, on a globe or map of Earth.
Suppose
you live 60 degrees North of the equator. You would go fist-over-fist six
times, then follow the path your arm makes into the sky and search that area
for the North Star—on the tip of the Little Dipper’s handle. Once you learn the
Little Dipper’s location in the night sky, it’s easy to spot and simple to use
to determine each of the compass points.
Orion
is also an easy constellation to use find direction. The three bright stars
that form Orion’s belt rise near due east and set near due west.
In the
1700s, people often became lost at sea because they did not know how to
determine their longitude, which cannot be determined using the stars. The Discovery of Longitude, 2013 winner of the R. Ross Annett Award for
Children’s Literature, is a historical picture book which explains how a carpenter, John Harrison, devoted his life to solving the
problem of finding directions east and west at sea.
Despite his dedication and
hard work, it took the King of England to make sure he got the recognition he
deserved. Thanks to Harrison’s work, everyone on Earth recognizes the
same time zones and navigation is much easier than it was when maps were made on clay tablets!




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