Unit 5 Vocabulary (Chapter 19, 20, 21)

the study of the moon, stars, and other objects in space

the imaginary line that passes through Earth's center and the North and South poles

the spinning of Earth on its axis

the movement of one object around another

the path of an object as it revolves around another object in space

one of the two times during the year when the sun is farthest north or south of the equator

a day when day and night are the same length

a push or pull

a push or pull

the force that attracts all objects toward each other