| A | B |
|---|
| trajectory | the path a projectile follows through space |
| ammeter | an instrument for measuring electrical current |
| tectonics | the process by which planetary features are formed |
| arc | a line in the sky from horizon to horizon, usually described by a celestial body |
| simulation | an artificial environment designed to imitate a real environment; normally used for training purposes |
| atmosphere | the gaseous mass of air surrounding a celestial body |
| orbit | the path an object follows around another object |
| atmospheric pressure | the force over a given area, caused by the weight of an atmosphere |
| mission status monitor | a television screen used during a mission to track astronaut activity |
| axis | a straight line about which a body rotates |
| meteorite | a meteor that survives passage through the Earth's atmosphere and then reaches the surface of the Earth |
| crater | a depression formed by the impact of a meteorite |
| mass | the amount of material in a object |
| density | the mass of a substance per unit of volume |
| longitude | the angular distance East or West from teh Prime Meridian |
| latitude | the angular distance North or South from the Earth's equator |
| diameter | teh length of a straight line through the center of an object |
| erosion | the process by which something is worn away |
| valve | a device used to control the flow of air or water |
| pulse rate | the number of heart beats per minute |
| escape velocity | the speed an object needs to be traveling in order to free itself from the gravitational pull of a planet |
| deploy | to release an object |
| balance | an instrument used to measure mass |
| volume | the amount of space an object takes up |
