The Lake County Astronomical Society

Observing the Moon: The Cat in the Moon

Jack Kramer

We've heard the nursery rhyme about the cat and the fiddle, and the cow jumping over the moon, but what ever became of that fiddlin' cat? Well, it's memorialized on the moon. If you take a look around the bright crater Aristarchus when it's near the terminator shortly before the full phase (about a 10 to 12 day old moon), you may see a combination of two craters and a valley that looks like the face of a cat.

In case you have trouble visualizing the face of the cat, I'll help out a bit with the illustration below (and add a few details that aren't really there!). Schroter's Valley forms one side of the mouth, and the shadow of an upland area forms the other side of the mouth.

Though I had observed this area of the moon many times, I first noticed this caricature when Shroter's valley was particularly prominent. In more advanced phases when the Sun is higher, the valley doesn't stand out nearly so well. I've shown the images with south up and west to the left. Some manipulation of your mental image may have to take place, since depending on your scope's orientation, the poor cat may be standing on its head!