If you haven’t already done so, read The Moons-lings fairy tale and How long is a day on the moon? You might be surprised! It won’t take long. Then come back and let’s have some two moons-fun!
In The Moonslings, Margie and Hal are snatched from their beds by an evil sorceress who whisks them off to her castle on the “back side” of Lunera, Urth’s closer and brighter moon.
They can’t see Lunera anymore because they’re standing on it. But from their new position they can still see Urth’s more distant moon, Ru.
They’re accustomed to seeing Ru from Urth, where it waxes and wanes but never changes diameter (just like our moon does when seen from Earth).
But from their new perspective, Ru is behaving in a bizarre fashion. Its diameter is changing drastically as the month progresses. Sometimes it’s huge in the sky and other times it’s very tiny.
Why? Let’s look at some diagrams.
On the left, Lunera and Ru are on the same side of Urth. The two moons are very close together, and, from Marge’s unique perspective, Ru would be HUGE!
On the right, Lunera and Ru are on opposite sides of Urth. Now, poor Margie can barely see Ru at all. It would be tiny.
In the situation I described in this post, Margie is standing on the “back side” of Lunera. She is always on the side of the moon facing away from Urth.
|What would happen if Margie was standing on the “front side” instead? Would Ru still get huge and tiny in the sky?
I suggest you get out some paper and colored pens or pencils and redraw the diagrams showing Margie’s new position. You might be surprised at what you learn!
When you’re finished, please leave me a comment and let me know what you learned. I love to hear from my young readers!