| A | B |
|---|
| astronaut | a person who travels in space |
| telescope | an instrument for making distant objects appear nearer and larger |
| satellite | an object that revolves around another object |
| tide | the rise and fall of the ocean mainly due to the moon's gravity |
| phase | the shape of the lighted part of the moon |
| orbit | the path an object follows as it moves around another object |
| revolution | movement of an object in an orbit around another object |
| axis | an imaginary straight line trough the center of Earth around which Earth rotates |
| rotate | to spin on an axis |
| planet | a large body of matter that moves around a star such as the sun |
| solar system | the sun, planets, and their moons, and other objects that move around the sun |
| crater | a large hole in the ground that is shaped like a bowl |
| star | a very large mass of hot, glowing gases |
