| Answer | Crossword Clue |
|---|---|
| RANGEFINDER | Instrument for determining the distance of an object |
| rangefinder | an instrument for finding the distance of an object |
| rangefinders | RANGEFINDER, an instrument for finding the distance of an object |
| stroboscope | An instrument for studying periodic motion or determining speeds of rotation by shining a momentary bright light at intervals so that a moving object appears stationary |
| stroboscopes | An instrument for studying periodic motion or determining speeds of rotation by shining a momentary bright light at intervals so that a moving object appears stationary |
| parsec | a unit of measure for interstellar space that is equal to 3.26 light-years and is the distance to an object having a parallax of one second as seen from points separated by one astronomical unit |
