| A | B |
|---|
| What does the prefix Geo mean? | Earth |
| What does the prefix Helio mean? | Sun |
| Who wrongly taught that the Earth was the center of the universe? | Ptolemy (taw' luh may) |
| What does the prefix retro mean? | Backwards |
| Why does Mars seem to go backward in our sky? | Earth is passing Mars Retrograde motion) |
| What two factors keep planets in orbit? | Inertia and Gravity |
| What planet did Galileo see that had moons going around it which proved not all objects orbit Earth? | Jupiter |
| What planet did Galileo see had phases which proved it orbited the Sun? | Venus |
| What is the name for the theory that all objects orbit the Earth? | Geocentric |
| What is the name for the theory that all objects orbit the Sun? | Heliocentric |
| What is the shape of orbits in our solar system? | Ellilptical (oval) |
| What Polish astronomer is given credit for the Heliocentric (Sun-centered) solar system? | Nicholas Copernicus |
| What would happen to an orbiting planet if gravity suddenly quit? | The planet would fly off in a straight line |
| What law says the planets try to keep moving in a straight line? | Inertia (of motion) |
| What does the word elliptical mean? | Oval |
| What did the ancient astronomers call the bright lights "wandering" among the stars? | Planets |
