| A | B |
|---|
| atmosphere | the layer of air that surrounds the earth |
| hydrosphere | layer of water that covers the earth |
| lithosphere | the solid surface of the earth |
| summer soltice | a point in the sky through which the sun passes on the first day of summer in the Northern Hemisphere |
| autumnal equinox | a point in the sky through which the sun passes on the first day of fall in the Northern Hemisphere |
| winter soltice | a point in the sky through which the sun passes on the first day of winter in the Northern Hemisphere |
| vernal equinox | a point in the sky in which the sun passes on the first day of spring in the Northern Hemisphere |
| phases | the differen't shapes that the moon appears to have |
| linar eclipse | occurs when the moon passes through the shadow of the earth |
| solar eclipse | occurs when the earth passes through the moon's shadow |
| nebular hypothesis | a hypothesis that the solar system formed from a dust cloud that contracted, or came together |
| protoplanets | whirlpools of matter, which were the beginningof the bodies of the sloar system |
| rotation | the turning of an object on its axis |
| revolution | the movement of an object along an orbit, or path, around another body |
| time zones | the divison of the earth into 24 equal segments |
