Why can’t two successive full moons be totally eclipsed?
Most people suppose that eclipses occur at random or in some pattern so complex you need a big computer to make predictions. You know the geometry is fairly simple, so you can build a simple argument to analyze this question. Remember that a total lunar eclipse occurs when the moon passes through Earth’s shadow. Earth’s shadow always points toward the ecliptic exactly opposite the sun, and most of the time the moon will pass north or south of Earth’s shadow, and there will be no eclipse. A lunar eclipse can happen only when the sun is near one node and the moon crosses Earth’s shadow at the other node. Now you can apply what you know about the moon’s phases. An eclipse season for a total lunar eclipse is only 22 days long, but the moon takes 29.5 days to go from one full moon to the next. If one full moon is totally eclipsed, the next full moon 29.5 days later will occur long after the end of the eclipse season and there will be no eclipse. Now use your knowledge of the cycles of the s
