After reviewing the wish list my son wrote for “Santa” (he’s a solid skeptic but plays along out of pity for his nostalgic parents), I had to ask him what he specifically had in mind when he wrote “giant plastik dinasors” on his list. Not only did I wonder what the wildly imaginative boy meant by “giant,” but I also inquired whether he might want to try something different from his usual favorites, the T-rex and Velociraptor.

He raised an eyebrow and looked at me like I was insane when I suggested my old favorite from school, the gentle Brontosaurus. “Mom!” he giggled. “There’s no such thing as a Brontosaurus! It’s an Apatosaurus! I’m only 7 and I know that.” Of course he’s right; the long-necked plant-eater I learned about in grammar school no longer exists as a Brontosaurus, but the name and classic image is too ingrained in my memory to forget.

I guess we have to keep on our toes if we want to keep up with an ever-changing world and possibly even convince our children we occasionally know what we’re talking about. Even some of the most basic facts are subject to change, right before our eyes. When I was in school there were only four oceans on our planet, and one morning I woke up and there were five.

Some of us are still getting used to the fact Pluto isn’t a planet anymore. Just a few days ago I was helping my daughter assemble a solar system model she received as a gift, and I was instantly reminded of the classic nine-planet model I must have assembled a hundred times as a child. It just wasn’t the same without the little ball that used to be known as the smallest and 9th planet from the sun.

Not to mention the demotion of Pluto totally spoils the nifty mnemonic device we always used for remembering the names of all the planets: My Very Educated Mother Just Served Us Nine Pizzas. Now there’s no pizza. Now what?

Pluto was first discovered in 1930 by an astronomer working from the Lowell Observatory in Flagstaff, Arizona. Scientists had already predicted the presence of a 9th planet in the solar system, which they called Planet X, and after many years of studying the sky a young astronomer finally spotted the mass. The discovery of the new planet, later named Pluto, made headlines across the world and allegedly inspired Walt Disney to add a new character to his collection, Mickey Mouse’s now beloved canine companion Pluto.

Pluto (the big rock, not the pup) officially lost its planet status back in 2006, after scientists realized it was not only much smaller than originally estimated, but there were other objects of similar or even larger size just beyond it. Pluto was ultimately designated a “dwarf planet,” along with similarly sized discoveries named Eris and Ceres.

Not everyone supported Pluto’s demotion, and many suggested promoting Eris and Ceres to planet status instead, giving us a total of 11 planets. My daughter Kaya fully supports this idea, and she considers herself a passionate advocate for the planetary reinstatement of Pluto, citing it’s “just not fair to award something as important as being a planet and then just take it back. That’s just not cool.” Indeed, and if it turns out there’s some form of sentient life on the frozen planet I’d imagine they’re highly offended.

By now there are already two additional dwarf planets added to the mix, Makemake and Haumea, allowing for a potential of 13 planets, had scientists not ultimately decided to change the definition of “planet” to exclude Pluto and the other newly discovered dwarf planets. That’s too bad because I kind of enjoyed the suggested mnemonic for 13 planets: My Very Excellent Mother Constantly Just Serves Us Nachos, Pizzas, Hamburgers, Meatballs and Eggplants.

We’re all sad for Pluto getting snubbed although it’s probably for the best, as scientists believe there could be thousands of objects similar to Pluto in the outer known parts of our solar system. We could simply make them all planets, but it would make for some pretty complicated solar system models. I don’t wish that sort of homework assignment on anyone! Not to mention the mouthful of a mnemonic it would take to help some hapless future generation memorize the 17,000 planets in our solar system.

Just because Pluto’s not a planet anymore doesn’t make it any less interesting for study. Since Pluto is so far away from the earth, little is known about its exact size or surface conditions. However, very soon we’ll know a great deal more about the cold and remote former planet.

In January 2006 NASA launched its New Horizons mission, which aims to be the first probe to study Pluto, its moons and other bodies within the Kuiper Belt, where Pluto lies. After traveling nearly a million miles per day for nine years, the spacecraft will make its closest approach to Pluto in July 2015.

Beginning as soon as January of next year (just a few weeks!), the spacecraft will begin using long-range photography to capture images of the former planet. The photography will continue as the craft makes its closest approach, where it will eventually travel at a distance close enough to see buildings if it were flying over Earth at the same distance.

An important step in the mission was completed this past Saturday when the long-traveling spacecraft finally “woke up” as scheduled and sent the signal that all systems were functioning normally. NASA scientists were thrilled by the good news. They’re extremely excited about the upcoming information, saying it could change just about everything we know about Pluto and give us amazing new insight into the mysterious universe around us.

Stay tuned fellow olds! There’s no telling what will be in our grandchildren’s textbooks!