| A | B |
|---|
| axis | imaginary line through the center of the Earth that the Earth rotates around |
| 24 hours | time it takes Earth to rotate one time |
| 365 days | time it takes Earth to revolve around the sun one time |
| sun | the center of our solar system |
| crater | hole in the ground that is shaped like a bowl |
| moon | satellite that revolves around a planet |
| orbit | the path an object follows as it moves around another object |
| Mercury | closest planet to the sun |
| Jupiter | largest planet |
| Pluto | farhtest planet from the sun |
| Saturn | has rings made up of ice particles |
| Mars | is more like Earth than any other planet |
| about 29 days | time it takes the moon to revolve around the Earth |
| new moon | no moon can be seen |
| full moon | brightly lit circle |
| phases | changing shapes of the moon |
| Neil Armstrong | one of the first astronauts on the moon |
| Galileo | one of the first astronomers to use a telescope |
| astronaut | person who travels in space |
| Apollo 11 | spacecraft that landed on the moon |
