Parsec
A parsec was an astronomical measure of length that stood for "parallax arc-second". It was based on the Earth method of measuring interstellar distances using trigonometry. A star located one parsec away from an observer would have a "parallax angle" of one arc-second.

Based on this, one parsec was exactly equal to 360×60×60 / 2π au (206,264.8 au or ∼3.26 light years).

Comparative list of lengths 

 
 The  was 2.2 milli-parsecs from the . There were no other vessels within 2 parsecs of there. ()

 The  was one-sixteenth of a parsec from 892-IV when it identified the  debris. ()

 The Enterprise used sensors to scan a one-half parsec radius, then increased to a one parsec radius. ()

 The Enterprise-D was supposedly thrown 0.54 parsecs from their position near the Paxans' homeworld. ()

 The Enterprise was to pass one parsec from a Klingon outpost. Pavel Chekov thought this was "close enough to smell them." ()

 The Varro generational ship passed within one parsec of the Natori system more than two months before encountering the . () 

 According to Data's reading of inertial guidance, the Enterprise-D traveled 1.4 parsecs in Nagilum's void without finding any sign of an exit. ()

 Zalkon was 2.3 parsecs distant from where the Zalkonian warship met the Enterprise-D. ()

 When the interphase began, the Enterprise was thrown 2.72 parsecs from where the Tholians' field captured them. ()

 When Tom Paris broke the warp 10 barrier, Harry Kim was unable to locate his shuttlecraft on sensors within 5 parsecs of the 's position. ()

 Chardis was discovered 5 parsecs from his homeworld of Mislen. ()

 In 2371, Neelix protested Dr. Ma'Bor Jetrel's request to examine him for metremia, saying he didn't want the doctor within 10 parsecs of him. ()

 Attenpting to recover Voyagers stolen main computer processor, Kathryn Janeway told  she had a client who needed a computer to run a colony about 20 parsecs distant. ()

 The regions of space known as 2279 PL and 2466 PM were both located approximately 22.3 parsecs beyond Cestus III and the Federation's chart limits during the late 23rd century. ()

 The Vega Nine probe traveled 23 parsecs beyond the borders of the Federation, as well as any manned expeditions, to explore the Beta Stromgren system. ()

 All Starfleet units and personnel were evacuated from an area covering 100 parsecs from the planet where Lazarus was found. ()

 The Metrons hurled the Enterprise 500 parsecs distant from their previous location. ()

At 98% of its pre-temporal flux strength, the Krenim Imperium spanned 5,000 parsecs of the Delta Quadrant. ()

See also 
 Cubic parsec

External link 
 

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Measurements