A constellation is a group of stars or constellations of stars that seemed connected to form a specific configuration. In three-dimensional space, which we observe most stars do not have a relationship with one another, but it can look like clusters at the ball the night sky. Humans have a very high ability to recognize patterns and throughout history have grouped stars that appear adjacent to the constellations. The composition is not an official constellation, which is known widely by the community but not recognized by astronomers or the International Astronomical Society, also called asterisma. The stars in the constellation of stars or which have rarely asterisma astrophysics; they just happen to appear close together in the sky just visible from Earth and is usually very far a part.
The grouping of stars into constellations is actually quite random, and different cultures will have different constellations, although some are very easily recognizable usually often found, such as Orion or Scorpius. The International Astronomical Society has divided the sky into 88 official constellations with clear boundaries, so that every direction only owned by one constellation only. In the hemisphere (hemisphere) north, most of the star constellations are based on the Greek tradition, passed down through the Middle Ages, and contains the Zodiac symbols. Various other patterns that do not officially exist together with the constellations and called asterisma, such as the Plough also known in the United States as the Big Dipper and Little Dipper. In addition, there are 88 modern constellations based on the breadth of the sky, measured in square degrees.