Constellations By: Caitlin, Emily, and Jerrell

Background of Constellations Our modern constellation system comes from the ancient Greeks. Constellations originated with the Sumerians and Babylonians Knowledge of constellations then came to Egypt where Greek scholars heard about them and wrote about them. No one is sure exactly where, when, or by whom they were invented. Only little detective work reveals a possible origin for constellations. The Greeks recognized and named forty- eight constellations. Many constellations were also recognized by the Arabs, Egyptians, and the Babylonians.

Zodiac Mythology The Zodiac constellations should not be confused with the signs of the zodiac Examples of the zodiac signs are Cancer; the crab, Sagittarius; the archer, and Taurus; the bull. People believe that these signs can tell them their future through horoscopes like in the newspaper everyday. No one really knows who exactly invented these myths, but ancient Chinese civilizations could have something to do with it.

Constellations Constellations are groups of stars that form patterns of imaginary things in the sky and are defined by exact boundaries. Animals, mythical gods and goddesses, and heroes are examples of these imaginary things created in constellations. The term "constellation" can also be referred to as the more noticeable stars that seem to form a pattern in a specific area.

Where are they located? 29 of the constellations are between the ecliptic and the North Celestial Pole. 47 of the constellations lie between the ecliptic zone and the South Celestial Pole. 12 of the constellations lie on the ecliptic, known as the “Zodiacs.”

What are they composed of? Constellations are composed of groups of stars.

How many are there? 88 constellations cover the entire sky in both the Northern and Southern Hemispheres.

Band of Zodiac Constellations The area known as the Zodiac is a band about 18 degrees wide centered on the Ecliptic. They are no different than other constellations except that they are patterns in that 18 degree band in the sky. The changing positions of the Sun, Moon and planets, make other stars look like they roam aimlessly about the Zodiac band, but stars only move over millions of years.

Relationship with the Months of the Year Much of astrology today is based on the relationship constellations have with the seasons.

Visibility of Constellations Annually, 55 of the 88 constellations come into view in the night sky from our latitude. Constellations like Ursa Major and Cassiopeia can be seen 8 out of the 12 months of the year. Zodiac constellations like Sagittarius and Scorpius can only be seen 3 months during the year. Although, these constellations and a few others are relatively bright and the easiest to learn. We actually are in pretty good location for seeing constellations. In a very dark sky, there can be so many stars visible that it is hard to pick out each of the patterns. Since Earth’s right side faces in different directions throughout the year, it makes it possible to different constellations at night.

Birth and Death of Stars The birth of a star starts when it first becomes dense cloud of gas. Hydrogen atoms then fall with increasing speed and energy (which heats the gas) toward the center of the cloud under the force of the star's gravity. Over for some millions of years, the temperature reaches amazing temperatures and then hydrogen within the star ignites and burns in a continuing series of nuclear reactions, marking the birth of a star. Stars expand as they grow old. their core runs out of hydrogen and then helium, the outer layers expand, it cools, and become less bright. It will then eventually collapse and explode. A star's life span and eventual fate are determined by the original mass of the star.

Movement Constellations seem to move across the sky because the Earth is rotating on its axis. The Earth moves in a way that makes it look as if the constellations are moving, creating an optical illusion. The constellations appear to move from East to West We could say that Earth rotates so we can see different constellations. As the Earth continues to rotate the constellations then “apparently” move across the sky.

In Conclusion… Constellations are groups of stars that make patterns in the sky which create imaginary things for the human eye to see. We chose constellations, because of the interesting patterns they create and the myths of the Zodiacs. Constellations are important, because they allow human imagination to go beyond reality.

Works Cited Free Online Psychic Chat N.p., n.d. Web. 25 Oct AbsoluteAstronomy.com N.p., n.d. Web. 25 Oct Tools for Science N.p., n.d. Web. 14 Oct Clackamas Community College N.p., n.d. Web. 30 Oct

Words Cited Cont. Windows to the Universe N.p., Web. 14 Oct Science Encyclopedia N.p., Web. 14 Oct Tour Egypt! N.p., Web. 14 Oct University of Wisconsin-Madison N.p., Web. 25 Oct "Constellation." Wikipedia MediaWiki, Web. 30 Oct