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themorikelifeThis rant is inspired by every instance of "It's okay Pluto, you're still a planet to me" that you can find on the internet.
The Kuiper Belt is home to so many objects that we are still discovering the big ones. The last time I checked in on what's what with regards to dwarf planets, there were only five. In my research for this post (because I do my fucking research), that number increased to nine.
Which is to say, there's always something new being discovered in the Kuiper Belt, so you can't assume that whatever you learned in middle school astronomy or wherever is going to stay the same forever. Astronomy isn't math, though I hear mathematics is also prone to new insights, just not at the current rate of astronomy. (Hello, exoplanets, I see you there.)
Three, it's discovery was kind of accidental? It took almost two decades to even confirm the existence of a ninth planet in our solar system. When Pluto was discovered, miscalculations abound. You see, astronomers did not correctly calculate the masses for Uranus and Neptune, and that discrepancy is where astronomers thought planet X existed. In their search for a legend that didn't exist, they found Pluto. Pluto which was a lot smaller than the calculations showed. Pluto that is weirdly reflective.
It wasn't until the Voyager and Voyager 2 missions in the 1980s that we even got an accurate measurement of the masses for Uranus and Neptune. There was no mysterious Planet X. There never was. The calculations for Planet X were incorrect to begin with. It's all very much like looking for a legend, and then finding some schmuck that turned out to be a weird little clown that everyone still likes for some goddamn reason.
Pluto was a lot smaller than expected, and it had a weird orbit. And it just defied the general definition of a planet for a very long time. A very, very long time. (And that's not even touching on the argument that Pluto and Charon are actually a binary planetoid thing.)
But Eris! Eris was discovered circa 2005. It remains the biggest TNO ever discovered and has more mass than our beloved Pluto. And scientists were on the verge of not calling it a planet, and some other scientists went, "Wait wait wait wait . . . what? This object is bigger than a known planet and you're not even going to call it a planet?"
That's when the International Astronomical Union (IAU) decided to official define the term "planet." Which is it's own section and explanation.
Anything that fits into two of the three criterion is called a dwarf planet. This includes Pluto and Eris, but it also includes Ceres which orbits in the asteroid belt, and so many other objects in both the Kuiper Belt and and scattered disc. A complete list of celestial objects that are currently considered dwarf planets can be found at this elegant and finely-crafted link. (And please ignore the fact that I keep linking to Wikipedia.)
Before I let you go, I suppose we have to answer one other question:
And I think that's beautiful.
(Also, Pluto and Charon are tidally locked and orbit a central point between them so even with these new astronomical terms, Pluto has to keep defying us. What the fuck?)
Thank you for coming to my TedTalk.
Some Astrology Facts to Know
You may have heard of the asteroid belt, where a bunch of asteroids hang out in the orbit between Mars and Jupiter. It's possible that if I say Kuiper Belt (pronouned KAI-per), you might not know what I'm talking about. So here is a simplified explanation: the Kuiper Belt is similar to the asteroid belt in that its an orbit of debris beyond the orbit of Neptune but on a much grander scale than the asteroid belt.The Kuiper Belt is home to so many objects that we are still discovering the big ones. The last time I checked in on what's what with regards to dwarf planets, there were only five. In my research for this post (because I do my fucking research), that number increased to nine.
Which is to say, there's always something new being discovered in the Kuiper Belt, so you can't assume that whatever you learned in middle school astronomy or wherever is going to stay the same forever. Astronomy isn't math, though I hear mathematics is also prone to new insights, just not at the current rate of astronomy. (Hello, exoplanets, I see you there.)
Something to Know About Pluto
It's status as a planet has always been in jeopardy. Since it's discovery in 1930, it has been an outlier. For one, it's smaller than any other planet, including Mercury. Two, it has a weird orbit not on the regular plane of rotation where the other planets sit.Three, it's discovery was kind of accidental? It took almost two decades to even confirm the existence of a ninth planet in our solar system. When Pluto was discovered, miscalculations abound. You see, astronomers did not correctly calculate the masses for Uranus and Neptune, and that discrepancy is where astronomers thought planet X existed. In their search for a legend that didn't exist, they found Pluto. Pluto which was a lot smaller than the calculations showed. Pluto that is weirdly reflective.
It wasn't until the Voyager and Voyager 2 missions in the 1980s that we even got an accurate measurement of the masses for Uranus and Neptune. There was no mysterious Planet X. There never was. The calculations for Planet X were incorrect to begin with. It's all very much like looking for a legend, and then finding some schmuck that turned out to be a weird little clown that everyone still likes for some goddamn reason.
Pluto was a lot smaller than expected, and it had a weird orbit. And it just defied the general definition of a planet for a very long time. A very, very long time. (And that's not even touching on the argument that Pluto and Charon are actually a binary planetoid thing.)
And then Eris happened
The thing that kept happening, especially in the last two or three decades in astronomy, is the continual discovery of other Trans-Neptunion Objects (TNOs). As the name suggests, a TNO is a celestial body that is in orbit around the Sun beyond the planet Neptune. Most TNOs that we know of are in orbit within the Kuiper Belt. Some objects exist in the scattered disc, which is a disc of dust beyond the Kuiper Belt. There is at least one object beyond the scattered disc that is close to being named a dwarf planet. It is so far out there that Neptune, the furthest planet in the Solar System, does not have a gravitational effect on it. Astronomers those objects detached.But Eris! Eris was discovered circa 2005. It remains the biggest TNO ever discovered and has more mass than our beloved Pluto. And scientists were on the verge of not calling it a planet, and some other scientists went, "Wait wait wait wait . . . what? This object is bigger than a known planet and you're not even going to call it a planet?"
That's when the International Astronomical Union (IAU) decided to official define the term "planet." Which is it's own section and explanation.
Planet vs. Dwarf Planet
In order to be called a planet, a celestial body must meet three criterion. It must:- have its own orbit about the Sun
- be of sufficient mass to be spherical, and
- have cleared its orbit of any other debris.
Anything that fits into two of the three criterion is called a dwarf planet. This includes Pluto and Eris, but it also includes Ceres which orbits in the asteroid belt, and so many other objects in both the Kuiper Belt and and scattered disc. A complete list of celestial objects that are currently considered dwarf planets can be found at this elegant and finely-crafted link. (And please ignore the fact that I keep linking to Wikipedia.)
Before I let you go, I suppose we have to answer one other question:
IS a dwarf planet a planet?
I say that depends on you. A lot of people do. A lot of people don't. I think the continual controversy around Pluto and its status as either a planet or a dwarf planet mostly speaks to people getting stuck on a piece of outdated information and they don't grow past that. Science is a continual accumulation of knowledge and that means definitions change. Dinosaurs had feathers. Whales used to walk on land. Pluto is not a planet-planet, but it is a dwarf planet, and that means the Solar System is bigger and more complicated than we originally thought.And I think that's beautiful.
(Also, Pluto and Charon are tidally locked and orbit a central point between them so even with these new astronomical terms, Pluto has to keep defying us. What the fuck?)
Thank you for coming to my TedTalk.
