A Honeymoon In Space by George Griffith

The period of Ganymede's revolution round its gigantic primary is seven days, three hours, and forty-three minutes, practically a terrestrial week, and on their return to their native world both the daring navigators of Space describe this as the most interesting and delightful week in their lives, excepting always the period which they spent in the Eden of the Morning Star. Yet in one sense it was even more interesting.

There the inhabitants had never learnt to sin; here they had learnt the lesson that sin is mere foolishness, and that no really sensible or properly educated man or woman thinks crime worth committing.