A metric unit of distance equal to 1015 kilometers. This is equivalent to about 621.371 trillion miles, 105.7 light years, or 32.408 parsecs. One exameter is approximately the distance from the earth to the Hyades star cluster in Taurus
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}