Pluto is a dwarf planet. "Planet" is right there in the name, so yes, it's literally a planet.
Ceres is also a planet. You'll be including that one too, right?
Pluto is a dwarf planet. "Planet" is right there in the name, so yes, it's literally a planet.
Ceres is also a planet. You'll be including that one too, right?
That was a friendly neighborhood OPA representative to talk about why Ceres should also be included
If you count dwarf planets, that puts our count at 13.
And we can't do 13 planets. It's unlucky.
I remember looking at an astronomy book at school and seeing Pluto's weird ass slanted orbit and thinking that it shouldn't be counted amongst the others. Felt really vindicated when Jim Carrey's kids in Me, Myself and Irene argued about Pluto not being a planet. The official definition was just cleanup.
This is what they took from us 
Pluto stole the attention back, not by name, but by best known of its class. Still the king.
However, Eris is more massive...
(Actual colors not as depicted.)
I imagine nasa would be perfectly fine with Pluto still categorized as a planet. It was just a handful of people at a IAU conference(many had left by the time the vote happened) that made the change.
Historically it's fine. Technically it's not. The thing is, it's still a type of planet, it's not like it's now called something completely different. It's more specific to fall in line with the likely many, many neighbors that are out there.
I would completely agree with you except IAU specifically said Pluto is a dwarf planet and that, for some reason, a "dwarf planet" is NOT a sub category of planet. It's its own thing and not a planet.
It was a weird conference and a weird vote.
Edit: "planet" IMHO is more of a traditional category like constellation. Some how a tiny rock like mercury is more like Jupiter than the tiny rock Pluto. It doesn't make much scientific senseso it seems more traditional. It would be like removing the name for a constellation because one of the stars is really a bright nebula or something.
It was a weird conference and a weird vote.
Nah, the other option was to add a bunch of planets, including Ceres right between Mars and Jupiter. If you wanted to keep things as close to what they were before, removing Pluto was the more conservative option.
There could be many options. My favorite is a reclassification. Terrestrial planets(first 4), gas planets (next 4) and drwarf planets (numerous). Though mercury could fit into the dwarf planet category which is fine with me. The current classification was made specifically to demote pluto with rules that particularly apply to it so that mercury would not fit into it. It was to keep the "planet" category special and to not have too many(keep it traditional). Seems a bit geocentric and less scientific.
The problem is that since Pluto was discovered, we've found many similar bodies. Astronomers suggest there could be hundreds.
If you define "planet" so that it excludes Pluto, 8 objects in our solar system qualify as planets. Any definition that includes Pluto qualifies at least 13 planets with a high likelihood that that number will increase every few years.
It is convenient to classify it as a dwarf planet but that doesnβt mean that βdwarf planetβ and βplanetβ are scientific categories in the purest sense of the term
What's the "purest sense of the term"? A planet is presently defined as a body which orbits a star, has enough mass to be roughly round, and has cleared its orbit of other objects. Dwarf planets are defined as fulfilling the first two criteria, but not the third.
I mean that these descriptions are somewhat arbitrary. Roughly round is not a very precise delineation, there will be edge cases where itβs not clear which category they fall into
Roughly round is not a very precise delineation
The actual qualification is "hydrostatic equilibrium", but I didn't want to complicate the point with technical mathematical jargon.
there will be edge cases where itβs not clear which category they fall into
Which is pretty par for the course so far as scientific classifications go. Classification is a human endeavor to attempt to neatly categorize things to better understand them, but the universe is what it is and defies tidy categorization. Just about any scientific classification you can devise will have edge cases and ambiguity.
Yes, the vote was held at the end of the final day of the two-week IAU conference, when fewer than 500 of the 2500 attendees were still there. This scheduling was almost certainly a deliberate move to take advantage of the predictably low number of members who would still be present.
If you're counting Pluto then you also need to count Ceres, Eris, and Sedna.
says who? I can't just accept pluto because I'm emotionally attached?
if red pandas can be pandas without actually being pandas than Pluto can be a planet dadgummit!!
Funny that the robot is from NASA - NASA didn't make the decision to declassify Pluto as a planet, and probably doesn't GAF. This was decided in 2006 by the International Astronomers Union at the end of the last day of their 2-week conference. The vote was taken after more than 80% of the 2500 attendees had already left.
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