#!/usr/bin/perl -w

use constant pi => 3.14159265358979;
use integer;

%planets = (Mercury => [88, 58.05e3],     Venus => [224.7, 108.45e3],
              Earth => [365.25, 150e3],    Mars => [687, 228.6e3],
            Jupiter => [4331.9, 780e3],  Saturn => [10760.3, 1431e3],
             Uranus => [30681, 2877e3], Neptune => [60266.3, 4059e3],
              Pluto => [90582, 7395e3]);     # but Pluto's orbit varies

sub circumference {
    no integer;
    pi * 2 * $_[0];
}

while (($planet, $data) = each %planets) {
    print "The speed of $planet is ",
      circumference($data->[1]) / ($data->[0] * 24), " megameters/h\n";
}