Who Knew?

I saw the astounding news today that scientists believe a ninth planet has been found, which they are calling, mundanely, "Planet Nine."{1} As I was reading about the evidence for this yet-unseen ninth planet, I thought to myself, "Wait a minute. Aren't there already nine planets?" I started listing them off, like you do when you're trying to remember the seven dwarves or the nine members of the Supreme Court: Earth, obviously; Mars; Venus; Saturn; Neptune; Uranus, that one's hard to forget; Pluto; Jupiter; and the one I always do forget, Mercury. That's nine. So, how can this new planet be the ninth? I hate a mystery, which is really to say that I love them, so even though I was supposed to be getting ready for work, I investigated further and found out, unbeknownst to me, that Pluto got demoted to less than a planet - a dwarf planet - in 2006. In the story about Pluto's demotion, bringing the number of planets to eight, this definitive statement appeared: "I promise you this, though, we're never going back to nine planets . . . ever."{2} That story was written in May, 2013 and here we are, less than 3 years later. With all of this technology at our fingertips, I think there's a trap to think we've got everything figured out, that we already know it all, when, actually, we don't. Did you know it's been estimated that "every year, researchers report more than 15,000 new species, and their workload shows no sign of letting up"?{3} The top new species for 2015 included a gor...
Source: Science - The Huffington Post - Category: Science Source Type: news