Space
Constellations
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World Almanac for Kids
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Thousands of years ago, astronomers grouped stars together to form pictures. These groupings, or the areas of sky that they cover, are known as constellations. Astronomers all over the world named the constellations after animals or mythological figures or tools.
Many of the constellations we use today were named by the people living in ancient Greece and Rome. But the southernmost parts of the sky could not be seen from that part of the world. Most southern constellations were named only later by European people, when they began traveling more in Earth's southern hemisphere.
In 1930, the International Astronomical Union established a standard set of 88 constellations. They cover the entire sky that is visible from Earth. Astronomers use constellations as a quick way to locate other objects. For example, from Earth, the other planets moving around the sun appear in different constellations at different times.
Two constellations are thought to resemble bears--Ursa Major (Great Bear) and Ursa Minor (Little Bear). The tail and hips of the Great Bear are also known as the Big Dipper. Ursa Minor is also known as the Little Dipper. Polaris, the last star in the handle of the Little Dipper, shines to the north and is called the North Star. The two stars at the end of the bowl of the Big Dipper always point in the direction of Polaris, making it easy to find.
The constellation of Cassiopeia looks like the letter "W" in the sky. In Greek mythology, Cassiopeia was an Ethiopian queen. She was the wife of Cepheus and the mother of Andromeda. According to tradition, when she died, she was changed into the constellation that is named after her.
From our viewpoint on Earth, the stars in the constellation of Orion seem to trace a picture of a hunter. (Orion in Greek mythology was a giant hunter killed by the goddess Artemis.) Three stars form Orion's belt. Betelgeuse (pronounced bet tell juice), a bright red star, is his left shoulder. Rigel, a bright blue-white star, is his right foot.