Now there are twelve planets, apparently, thanks to a draft resolution from the International Astronomical Union's General Assembly.
Really I don't care that much if Pluto is a planet or not. Astronomers, for all of their empirical, stiff exterior, however, have an emotional attachment to it—one way or the other, for or against. It's not about numbers, no matter what the verbiage in the draft resolution says—Pluto remains a planet because it has always been a planet.
And that's OK with me.
Pluto would always have nostalgia saving its status. Maybe not just nostalgia—inertia. Emotional inertia. Discovering another planet in the solar system is a big deal. For all of my cynicism, I recognize that. It's like discovering a new continent or island on Earth, or discovering a new element. To try to take away the prestige of a fundamental discovery would not even be seriously considered. The solar system is our neighborhood, and when new neighbors are discovered it makes the place that we live more interesting. As residents, we become accustomed to the neighborhood and we are comfortable that we know all of its other residents. Even though all of these objects have always existed in the solar system, they never had status, and now that there is the opportunity for status, there is the opportunity to identify more residents and to slightly change what we know about our identity.
It's funny what a title can do. Suddenly, Ceres has status. Now it is important. On 15 August, Ceres was an asteroid. On 16 August it is a planet. We learn about the asteroid belt as students, floating there uninterestingly between Mars and Jupiter, not taking on any life or importance of its own. A footnote—something that has to be covered after the rocky planets but before you get to the gas giants.
Now Ceres is a planet. And so is Pluto's moon Charon, and an object known as 2003 UB313 that is so far away that it takes approximately 560 years to make one revolution. What's more important is that there are likely more objects out there that will be known as planets. They just have to be found.
There are candidate planets...
- 2003 EL61
- 2005 FY9
- (90377) Sedna
- (90482) Orcus
- (50000) Quaoar
- (20000) Varuna
- (55636) 2002 TX300
- (28978) Ixion
- (55565) 2002 AW197
- (4) Vesta
- (2) Pallas
- (10) Hygiea
Yeah, I certainly sound like a space cadet about all of this, but I don't mind. My cynicism has hardened me sufficiently to avoid getting too excited about personally exploring space, but the discovery of the strange things that are out in the solar system or universe—or any discovery on Earth—still excites me. It's the only part of my self that still connects to the six-year-old in me.
Why is the planet status taken away from Pluto all of a sudden? I can understand how an asteroid can evolve into a planet, but how can a planet no longer be called one?? :O
Pluto is still considered a planet, but its status as a planet has been debated for years. As a planet, it is relatively small; it is the seventeenth largest body in the solar system (by radius). It is smaller than the other eight "classical" planets, and also the four Galilean moons of Jupiter, Europa, Io, Callisto, and Ganymede; our Moon; Saturn's moon, Titan; Neptune's moon, Triton, and 2003 UB313 (Titan and Ganymede are also larger than Mercury). The debate centered on the fact that Pluto was too small to be a planet, but there was no absolute definition of what a planet was—which is what this draft resolution is aimed at resolving.
Though Pluto didn't change, the perception of what is a planet changed.