October 23, 2017  SUN & MOON & STARS

Do planets really have moons? Well, yes and no. In 1992 my youngest son came home from school one day with a howler. He was agog: His teacher said their class was going to write a letter to NASA (the USA’s National Aeronautics and Space Administration—my employers) to ask why our moon had no name.

“No name? What do you mean?” I asked. He enlightened me:

“Our teacher said Jupiter has many moons; and he rattled off the names of those moons. “But our moon has no name of its own.” I was dumbfounded by this conundrum out of the blue, but it was a “teachable” moment and I rose to the challenge.

“Long ago,” I explained, “our ancestors gave everything its name. The star that gives us light and energy by day they called ‘Sol’ or ‘Sun’; the dull globe that shines above at night they called ‘Moon.’ So Moon is the natural satellite that goes around our planet, Earth. I reminded my son of that catchy Disney song, ‘There’s just one Moon and one golden Sun/And a smile means friendship to everyone.’”

My son looked a bit unsure what I meant. An adult has no problem recognizing a metaphor as such; not so children; it was tough making an eleven-year-old child see that subtle point. I had to elaborate.

“Who is he smartest scientist you ever heard of?”

“Einstein,” my son answered.

“So if someone said you were the Einstein of your class, you know what he means?”

“Yes,” it means I was the smartest person in our class,” he answered with a smile and no hesitation.

“Correct,” I replied. “Calling you Einstein is like calling Callisto (a satellite of Jupiter) a moon.”When we do so we are using a metaphor–to describe what is new or strange by likening it to something we already know. When astronomers found that other planets also had natural satellites going around them, they thought those satellites were “like moons.”

His teacher’s ignorance was a different matter. It was a case of teaching from newspapers in stead of doing a bit of research first. My elementary school teacher used to say, “A little education is a dangerous thing.” So I wrote a letter to the teacher of my son’s class offering to come and explain “moon” to her class. She never replied. Either she did not believe me (there are people like that!) or she was too embarrassed to respond.