| A | B |
| alien | someone from another place; a noncitizen |
| celestial | of the sky or the heavens |
| extraterrestrial | occurring outside the earth |
| galaxy | star system |
| intergalactic | between galaxies, or between star systems |
| interplanetary | between planets |
| interstellar | between stars |
| invention | a new device or process developed through study |
| launch | to start something in motion, such as sending up a capsule |
| malfunction | a failure to work correctly |
| mission | a task |
| rendezvous | a prearranged meeting |