OUTER SPACE

GALAXIES

• Our Galaxy's name is "The Milky Way"
• A galaxy is a massive group of stars, star clusters, interstellar gas and dust, and dark matter which is all gravitationally bound together.
• There are three kinds of Galaxies, Spiral, Elliptical, and Irregular. The only difference between the three is what shape that they are.

SPIRAL GALAXIES

• The Milky Way and andromeda are both spiral galaxies
• Their long twisting arms are areas where stars are being formed.
• The large bright stars created in the waves don't live very long. Their large size makes them burn all their fuel quickly.

ELLIPTICAL GALAXIES

• The stars in an elliptical galaxy are often very close together making the center look like one giant star. If the Earth were inside an elliptical galaxy it would be bright both day and night.

IRREGULAR GALAXIES

• Irregular Galaxies are simply all the galaxies which are not spiral or elliptical. They can look like anything and have many different characteristics.
• . Many irregular galaxies probably used to be spiral, or elliptical until they had some kind of accident which changed them such as crashing with another galaxy.

STAR CLUSTERS

• Star clusters are groups of stars close to each other in space that appear to have roughly similar characteristics and, therefore, a common origin.