IAU Demotes Pluto to 'Dwarf Planet' Status 426
davidwr writes "It's official. Pluto's been demoted. It's now one of several 'dwarf planets.' I guess we can drop the 'Period' from 'Mary's violet eyes make John stay up nights.'" (Of course, no one says you have to privately agree with the International Astronomical Union.) Several readers have contributed links to the BBC's coverage of the downgrade, as well as the usefully illustrated story at MSNBC.
Astrologers panic! (Score:5, Insightful)
So will this render all astrological predictions which took Pluto into account as invalid? I'm sure the kooks will come up with some excuse to explain how their previous charts were accurate at seeing the future as if they ~knew~ this all along.
Why is this "breaking news" (Score:4, Insightful)
Now that would be breaking news!
Re:Astrologers panic! (Score:5, Insightful)
Re:That changes everything (Score:5, Insightful)
Stupid (Score:2, Insightful)
Create the new definition with a stipulation that for historical reasons, Earth's generally accepted planets will remain in the planet class. There's nothing wrong with that. It's not like any meaningful astronomy research is going to get confused.
Re:So why does Neptune qualify? (Score:3, Insightful)
Re:Pluto's just being picked on for being small... (Score:2, Insightful)
From before Pluto was a planet (Score:2, Insightful)
Re:Stupid (Score:5, Insightful)
Given the level of scientific illiteracy, what the hell is the point of taking something that everyone does know and declaring it to be wrong?
"Everyone" knew there were eight planets prior to 1930. Did the world end when it was changed to nine, especially with something that wasn't even obviously a planet?
Guess what? A whole generation of children will grow up with the new, consistent rules and won't know any different. What's unarguable is that the new rules are better. I'm all in favor of fixing things that are broken, even if certain curmudgeons are too mentally inflexible to make the adjustment. See also: the metric system in the US, which is kept down by the same curmudgeons.
Pluto and Neptune (Score:3, Insightful)
Doesn't that mean that Neptune also hasn't cleared it's neighborhood? It's orbit overlaps that of Pluto. So why is IT a planet?
Re:my take on it: (Score:1, Insightful)
Re:my take on it: (Score:3, Insightful)
Not that it really matters all that much. As other astronomers have commented, they mostly just say "body" and give a list of specs. Terms like "planet" are a bit too vague to be useful as technical terms. After all, Mercury, Luna and Pluto are more like each other than either is like Venus, Earth or Titan. This by itself tells us that "planet" can't be a very useful term for any technical purposes.
This is of interest mostly to mass-media journalists and authors of school textboks.
Re:my take on it: (Score:3, Insightful)
Clyde Tombaugh is surely spinning!
In astronomy, they don't call it spinning, but "ro...tat...ing" (making finger quotes as I type). You have to give some respect to the man who discovered the biggest snowball that side of the asteroid belt
Re:my take on it: (Score:3, Insightful)
.. but given enough time... (Score:3, Insightful)
But isn't the Moon's distance from Earth slowly increasing thus, surely, the binary planet definition will also apply to the Earth+Moon eventually?
Re:my take on it: (Score:2, Insightful)
That's the part I don't get.
We have a rather large body in the neighorhood of our orbit. We call it Luna. Are we not a planet?
Jupiter has groups of asteroids [wikipedia.org] that share its orbit. Not a planet?
Neptune hasn't cleared Pluto out of its orbital space. Not a planet?
Scale up the Pluto/Neptune situation and consider a hypothetical stellar system with an Earth-sized body in an highly ellipical orbit that crossed that of a gas giant. Would neither be planets?
Some astronomer help me out here...
Re:my take on it: (Score:3, Insightful)
Legal issues.
If we get off this rock, we will probably allow asteroid mining. It would then be OK to reduce an asteroid to rubble to extract the ore that you want. Now imagine Pluto has some valuable Ultra-rareium at its core. Is it OK for a company or a country to smash it to pieces?
These definitions are important so laws can be made. Is it OK to bury radioactive waste in an asteroid? What about Mars? Does this apply to all planets, or just rocky planets?
So, while it might not matter scientifically, (like political borders don't matter to geologists), they may be important anyway.
Re:my take on it: (Score:3, Insightful)
I agree...screw Neptune.
The problem is that the public wasn't right. (Score:3, Insightful)
No. We've known for decades that the "planet" Pluto was far smaller than any other planet and made of fundamentally different stuff. And through all that time, astronomers let it go because every time one of them mentioned that Pluto wasn't really a planet he was shouted down by the public. Now that we know there are dozens of bodies just like Pluto - and some even larger - what little scientific accuracy there was in calling Pluto a planet is completely lost.
Face it, the astronomers weren't going to come out of this looking good no matter what:
1. They develop a definition of "planet" that includes Pluto and, by association, dozens of other bodies. Effect: The public freaks out about "those crazy scientists". (For proof, just read the previous article on this subject here at
2. They develop a definition of "planet" that excludes dozens of small bodies and, by association, Pluto. Effect: The public freaks out about "those crazy scientists". (For proof, read this thread).
3. They develop an entirely new set of definitions using brand new words that no one's ever heard of before. Effect: The public freaks out about "those crazy scientists" who are trying to complicate a "perfectly simple situation".
And, of course, there's the fact that any one who gets upset over this really has far too much free time on their hands.