I love eclipses, and astrophysics, and orbital mechanics. Suppose you're a rocket in orbit of the Earth. You can apply forward thrust (along the direction of your orbit), reverse thrust, upward thrust, and downward thrust. What thrust or combination of thrusts would you use to change the phase of your orbit? It's a fascinating introductory exercise to the concept! And did you know that we have solar eclipses every night here on Earth? They're simply not called that, because we have another word for them: "nighttime." When it's your own celestial body that's eclipsing the sun, it's called night. At least in a star system with only one star!