About two hundred fifty million years ago, Earth’s land masses existed as a single supercontinent called Pangea, and through plate tectonics, or continental drift, the continents broke apart and continue to move about an inch each year, producing volcanic eruptions and earthquakes. The seasons result not from Earth being closer to the Sun in summer and farther away in winter, but from the tilt of Earth’s axis: in summer Traverse City is pointed more directly at the Sun, while in winter it is tilted away so the rays arrive at a greater angle, more energy is lost through scattering and reflection in the atmosphere, and less heat reaches the ground. Because Earth’s orbit is not a perfect circle, it is actually three million miles closer to the Sun during Traverse City’s winter. On July 11, 1969, the Apollo 11 crew gave the world a man on the Moon, with Neil Armstrong and Buzz Aldrin walking on the surface while Michael Collins piloted the Command Module around the Moon fifteen times over twenty-four hours. Footprints left there will remain because there is no weather on the Moon to erode them, and the American flag was held out by a horizontal rod because it could not flap in a breeze; when the astronauts lifted off, engine exhaust blew the flag over. Sunlight takes 8.3 minutes to reach Earth.