Back in the dark ages, when I was a kid, there were nine planets. Mr. McClain, our science teacher, taught us a mnemonic to remember them. “My very educated mother just served us nine pizza-pies.” Lots of kids learned this mnemonic, though some mothers served other P-foods. Other mothers showed their kids nine planets instead. Still, it helped us learn the order of the planets in the solar system. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
Then, when I was in second grade, chaos took hold of the elementary science classroom. Neptune’s and Pluto’s orbits cross, so from 1979-1999, Pluto was actually closer to the sun than Neptune. So the mnemonic changed. My very educated mother just served us pistachio nuts. Problem solved. In 1999, we reverted back to the pizzas, and we shouldn’t have to worry about the pistachio nuts for another 250 years.
But then in 2006, Pluto was declared a dwarf planet. That’s good, because there are lots of dwarf planets, and our mnemonic sentence was in danger of becoming a mnemonic paragraph. But with just eight planets to remember — now that’s not so bad. So old mom has been variously serving “noodles,” “nachos,” “naan,” and, well, “nothing.”
Now, the International Astronomical Union recognizes three dwarf planets. These bodies are large enough to have enough gravity to be round, but they are not large enough to have cleared the neighborhoods of their orbit. Right now, there are three named dwarf planets: Pluto, Ceres, and Eris. But there are at least 42 other bodies floating around up there that might also fit this definition.
National Geographic Children’s Books thought it would be a good idea to have a mnemonic so school children can memorize the names of all eleven planets now. So they had a contest to come up with one. Ten-year-old Maryn Smith of Great Falls, Montana had the winning entry. “My Very Exciting Magic Carpet Just Sailed Under Nine Palace Elephants.” Poor Mom was left out of the picture entirely.
The mnemonic is being recorded into a song by Grammy-nominated singer and songwriter Lisa Loeb. There’s no word yet on what’s going to happen when the other 42 dwarf planets are named.