"I don't know," Hannah confessed, for the class had progressed beyond simply finding constellations, and now had to do with half a dozen charts simultaneously used to track and predict the movements of planets, stars, and other celestial bodies in relation to one another. Two years before she had been able to keep up, but now that she was having to do much more multitasking, Hannah's comprehension of the subject was slipping. "If I could hex off sixty-two of Jupiter's moons and leave them with just one, like us, I really would," she swore, flipping open her book to the chapter that spoke about the planet and its unbearably high tally of orbiting objects.