| A | B |
|---|
| Greenhouse | atmospheric warming caused by the ability of the air to retain heat |
| Ions | Positively charged atoms |
| revolution | movement of the earth as it orbits the sun |
| rotation | movement of the earth as it spins on its axis |
| ozone | ultraviolet radiation is absorbed in this layer |
| 24 hours | earth completes one rotation |
| gravity | keeps us from falling off the earth as it spins |
| astronautics | science dealing with space travel and spacecraft |
| absolute zero | temperature at which atoms are at their lowest possible energy level |
| orbit | to revolve around |
| satellite | any object that orbits a larger object |
| stage | a set of rocket engines and their fuel tanks |
| payload | the cargo carried in the nose of a rocket |
| spring tide | tides that are higher or lower than the normal tide because the gravitational pull of teh sun and moon are combined |
| neap tide | seems to be no tide at all |
| lunar month | name given to the amount of time it takes the moon to revolve around the earth |
| maria | plains of the moon |
| solar eclipse | moon moves directly between the earth and the sun, blocking the sun from our view |
| full moon | entire sunlit side of the moon is visible |
| new moon | sunlit side of the moon is hidden from view and no moon appears |
| Sir Isaac Newton | formulated the three laws of motion |
| Wernher von braun | German born scientist who made the U.S. the leader in space exploration |
| Robert H. Goddard | "Father of Modern Rocketry" |
