Spiral, Irregular and Ellipitical
A galaxy is a group of stars and other space stuff. The stars tend to spin around a center of high gravity, sort of like the planets spin around the Sun in the Solar System. Galaxies are huge and can have trillions (way bigger than billions!) of stars. As big as galaxies are, they are generally separated by large areas of empty space. There are even clusters of galaxies that are separated by even larger areas of space. Scientists think there are over 100 billion galaxies. Wow, the universe is huge! Milky Way We live in the galaxy called the Milky Way. The Milky Way is part of cluster of around 3,000 galaxies called the Local Group. The Milky Way is a spiral shaped galaxy and is estimated to be made up of around 300 billion stars. Types of Galaxies There are three main types of galaxies depending on their shape: Spiral - The spiral galaxy has a number of long arms that are spiraling around the center. In the center of the spiral galaxy are older stars while the arms are generally made of new stars. Elliptical - A mass of stars clumped together in the shape of an elliptical disc. Irregular - Any other shaped galaxy is generally lumped into the category of irregular. It is thought that most irregular galaxies are formed by two of the other three types of galaxies crashing into each other.
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