When dealing with astronomical objects, distances are seldom specified in kilometers, because the numbers rapidly get too big to be manageable. Instead, AU, LY, and Parsecs are used

1 Astronomical Unit (AU) - Distance from Earth to Sol
150 million km

1 Light Year - Distance light travels in one standard year 63,240 AU / 9.46 trillion km / 9.46 x 1012 km

1 Parsec - Distance at which 1 AU would subtend and angle of 1" of arc
3.26 light years / 206,000 AU
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Development Notes
Text by M. Alan Kazlev

Initially published on 09 October 2001.