given that 1 km is 62.5 % of 1 mile pi = 3.142 distance to planet 1 = 0.35 au distance to planet 2 = 0.7 au distance to planet 3 = 1.4 au distance to planet 4 = 5.6 au distance to planet 5 = 9.1 au distance to planet 6 = 17.5 au distance to planet 7 = 29.4 au what they took to bed with them that evening would require some mathematical knowledge .