Letter From Johannes Kepler to Galileo Galilei, Delivered in April of 1610:

          “There will certainly be no lack of human pioneers when we have mastered the art of flight.  Who would have thought that navigation across the vast ocean is less dangerous and quieter than in the narrow, threatening gulfs of the Adriatic , or the Baltic, or the British straits?  Let us create vessels and sails adjusted to the heavenly ether, and there will be plenty of people unafraid of the empty wastes.  In the meantime, we shall prepare, for the brave sky travelers, maps of the celestial bodies - I shall do it for the moon, you, Galileo, for Jupiter.”


from: The Watershed -A Biography of Johannes Kepler, by Arthur Koestler