Article I, Section 8, of the Constitution, which enumerates the powers of Congress and provides Congress with the authority to make all laws necessary and proper to carry them out; also referred to as the elastic clause.
There is an exact numerical answer to this question. By definition, 1 light year is exactly 9,460,730,472,580,800 meters. By definition, 1 mile is exactly 1,609.344 meters. So, 1 light year is exactly 5,878,625,373,183 and 849/1397 miles, by definition.
1 light year is 5.878625 trillion miles 5878625000000 miles in one light Year Divided by 36,373 (the speed of New Horizons) = 161620570.203 Hours Divide Hours by 24 to get days = 6734190.42513 Days Divide Days by 365 to get Years = 18449.8367812 Years. It will take New Horizons, our fastest space craft, 18,450 years to go ONE light year.