Despite the seemingly random blanket of stars that make up the night sky, astronomers have found 88 official constellations, or defined groups of stars that can be mapped and named. The majority of the most common constellations can be clearly viewed without a telescope.
Ursa Major, also known as the Great Bear is the most famous of all constellations, thanks to its most famous feature, the Big Dipper, which makes up roughly half of the Ursa Major constellation. The ladle-shaped group of stars is one of the most visible and easily distinguishable constellations in the sky.
Ursa Minor is the little brother of Ursa Major and its name is Latin for "Small Bear." This constellation is located near Ursa Major in the Northern Hemisphere and is most recognizable by the Little Dipper, a group of stars that look like a miniature version of the ladle-shaped Big Dipper. Another famous feature of this constellation is Polaris, known as the North Star which is located at the end of the Little Dipper's handle.
The constellation Orion, also known as the Great Hunter, is a highly visible and extremely recognizable pattern in the night sky. It is located on the celestial equator, and therefore is visible from all parts of the world. Orion is recognizable by three bright stars -- Mintaka, Alnilam and Alnitak -- which form a belt-like pattern. Orion is based on Greek mythology and the constellation was viewed by early Greek astronomers as a hunter seeking to slay its neighboring constellation, Taurus the Bull.
Cassiopeia is a constellation located in the upper portion of the Northern Hemisphere and was one of the first constellations discovered by Greek astronomers in the second century. Cassiopeia forms a W shape and is composed of five very bright stars, making it easy to find and view in the night sky. Cassiopeia is located opposite of the Big Dipper. The constellation's legend is based on the Ethiopian queen Cassiopea, who was known for her unrivaled beauty and vanity.