What does a children’s nursery rhyme and astronomy have in common? Plenty, and the former is quite helpful in understanding one aspect of the latter: the moon’s phases. Everyone is familiar with the ...

The short, nonsense rhyme “Hey Diddle Diddle” might be the most recognizable nursery rhyme of them all. It even gave birth to a common phrase—”over the moon”—which is part of the rhyme, as we’ll see ...