A metric unit of distance equal to 1012 kilometers. This is equivalent to about 621.371 billion miles or 0.1057 light year. The distance from the earth to the nearest star (other than the sun) is about 40 petameters
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}