Notes on the eclipse…

Isaac Asimov in his extended Foundation series (it brings together the Foundation Trilogy, the robot novels, and The End of Eternity) commented toward the end during the search for Earth that humans’ home is an E-type planet with a very large moon. Some gas giants have even larger moons, of course, but Earth’s satisfies the Goldilocks Principle twice over: its distance from the Sun and its diameter are just right so that it just blocks the Sun. That occurs about every eighteen months on Earth...