1. I wish I’d seen the Moon shortly after it formed, 4.5 billion years ago. That was in the Hadean Eon—Earth’s first eon. The Moon was three to five times closer to Earth. Big. A storybook moon. Like the one in Italo Calvino’s story “The Distance of the Moon.” In the story the Moon had an elliptical orbit. When it came near, you could go out in a boat on the ocean, put up a ladder, and climb up to it. And why do this? Because. On the Moon, moon-milk could be obtained.

Pterosaurs. Flying reptiles with long beaks, brightly colored crests, and membranous wings. Some species were small but someazhdarchids—were as