- identify constellations in the northern hemisphere
The constellations that are visible in the Northern Hemisphere change
from season to season. During summer the Earth is on one side of the
Sun and the dark side of the Earth is facing one half of the celestial
sphere. During winter, once the Earth has moved to the other side of
the Sun, the dark side of the Earth is facing the other half of the
celestial sphere. So some of the constellations are only visible to
us during some parts of the year. Polaris, and the other stars near
it, are always visible to Canadians though because they are above the
Earth during any season.
Depending on the Earth’s position relative to the Sun, different
constellations are seen at different times of the year.
To locate Polaris, one first needs to find Ursa Major, or “Big Bear,”
which is a polar constellation. Seven stars of Ursa Major are brighter
than the rest, and are recognized by most as the Big Dipper. The two
stars at the end of the “pan” part of the dipper point toward Polaris
as you move from the bottom of the pan to the top. Polaris itself forms
part of the Little Dipper, which is much dimmer, and only visible in
very dark skies. The two Big Dipper stars which point to Polaris are
commonly called “Pointer Stars.”
By locating the Pointer Stars on the Big Dipper, one can
easily find Polaris, and thus a northerly direction!
most Native Canadian cultures called the Ursa Major constellation “The
Bear,” the Ojibwe nation called it the Great Fisher. Legend has it that
the Fisher, along with other winter animals, tried to steal warm
weather from the summer animals. While fleeing with the bag of summer,
Fisher was struck by a hunter’s arrow and was flung high into the sky.
The Creator recognized that the Fisher was only trying to protect his
fellow winter animals from starvation and cold, so he placed Fisher
among the stars. The Fisher was then visible all year long, symbolizing
the harmony between the seasons. (http://www.virtualmuseum.ca
Finally, it is worth mentioning that though constellations appear to be
stars clustered together, they are often, in fact, very far away from
each other. From our vantage point on Earth, we cannot distinguish the
“depth” of each star in the sky, and as a result, stars that lie in the
same direction from the Earth may look as though they are all the same
distance from the Earth – on a distant celestial sphere.
Stars which appear to be close together in a constellation are usually
away from each other, when we take depth into account.