| A | B |
|---|
| Black Hole | The remains of a supermassive star that has exploded and collapsed in on itself. Its gravity is so strong, no light can escape a black hole. |
| Constellation | A group of stars that form a pattern or shape in the night sky. There are 88 official constellations used by astronomers to locate objects and stars in the night sky |
| Universe | All existing matter and space considered as a whole; the cosmos. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago. |
| Fusion | A nuclear reaction that occurs naturally in the center of stars. It is releases a tremendous amount of energy in the form of radiation |
| Galaxy | A group of stars usually numbering in the billions that orbits a common mass and bound together by gravity. |
| Nebula | A large cloud of gas and dust in space and spread out over and immense volume. They are where stars and solar systems are born |
| Light Year | The distance that light travels in one year |
| Supernova | Brilliant explosion of a dying supergiant star |
| Big Bang Theory | The initial explosion that resulted in the formation and expansion of the universe |
| Microgravity | The condition of experiencing weightlessness in orbit |
