| A | B |
|---|
| constellation | A pattern of stars in the sky. |
| galaxy | A giantstructure that contains hundreds of billions of stars. |
| universe | All of space and everthing in it. |
| light-year | The distance that light travels in one year. |
| black hole | The remains of an extremely massive star pulled into a small volume by the force of gravity. |
| binary star | A star system that contains two stars. |
| spiral galaxy | A galaxy whose arms curve outward in a pinwheel pattern. (Like our milky way) |
| irregular galaxy | A galaxy that does not have a regular shape. |
| elliptical galaxy | A galaxy shaped like a flattened ball, containing only old stars. |
| big bang theory | The initial explosion that resulted in the formation and expansion of the universe. |
