Answer: parsecs

AnswerCrossword Clue
PARSECSAstronomical distances
PARSECSAstronomical measures
PARSECSLong distances
PARSECSMeasures for interstellar space.
PARSECSUnits of measurement, 19.2 trillion miles.
PARSECSUnits for astronomical distances.
PARSECSSpace distances
parsecsPARSEC, a unit of astronomical distance
parsecsA unit of distance used in astronomy, equal to about 3.25 light years (3.08 Î 1016 meters). One parsec corresponds to the distance at which the mean radius of the earth's orbit subtends an angle of one second of arc