How many planets are in the Solar System?

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

-Slacker-

Golden Member
Feb 24, 2010
1,563
0
76
Christ, people on the internet act like they have some sort of personal stake in something as trivial as Pluto's "planethood". 'The hell difference does it make to you, as someone who is almost certainly not a professional astronomer?
 

IronWing

No Lifer
Jul 20, 2001
72,970
34,172
136
Christ, people on the internet act like they have some sort of personal stake in something as trivial as Pluto's "planethood". 'The hell difference does it make to you, as someone who is almost certainly not an astronomer?

Pluto losing its planethood stripped me of my personhood. I think that is a pretty big deal. Wouldn't you agree?
 

-Slacker-

Golden Member
Feb 24, 2010
1,563
0
76
If you don't even care about this thing, as you shouldn't, then why make a thread about it?
 

Lemon law

Lifer
Nov 6, 2005
20,984
3
0
How can a planet named after a Walt Disney character's dog be so cruelly demoted to a mere planetoid status?

Is nothing sacred? Seeing is believing, and I saw it in an animated cartoon.
 

gorobei

Diamond Member
Jan 7, 2007
4,030
1,528
136
THERE ARE EIGHT PLANETS!!!!!
2e1axrq.gif
 

HeXen

Diamond Member
Dec 13, 2009
7,837
38
91
This reminded me of when they were selling plots of land on Mars. I wonder what became of all that.
 

Mr. Pedantic

Diamond Member
Feb 14, 2010
5,027
0
76
Pluto has much more in common with other dwarf planets than the rest of the planets; by comparison, it really is very dissimilar to the other planets.

If Pluto is a planet then so are Ceres (in the asteroid belt), Pluto, Haumea, Makemake, Eris, 2007 OR10, Sedna, Quaoar, Orcus, and probably many other undiscovered "dwarf planets".

Personally, I'd define a planet as an object big enough to retain an atmosphere, but not so big it starts nuclear fusion in its core. Which would rule out Mercury as well. :sneaky:

Posted from the second planet in a system of seven. ;)

Technically, that would mean Titan would be a planet, as would Rhea, Triton, Dione, and most comets.

Also, Mercury has a (faint, high-turnover) atmosphere.
 

sao123

Lifer
May 27, 2002
12,653
205
106
Counting Phaeton, I believe there are still 9, though we still have not located the supposed 10th planet in the OORT cloud.
 

dennilfloss

Past Lifer 1957-2014 In Memoriam
Oct 21, 1999
30,509
12
0
dennilfloss.blogspot.com
They had a chance to adopt a simple, logical definition of a planet as a body that directly orbits a star and is massive enough that gravity would impart a spherical shape but not massive enough to start any core fusion. There was no need to bother with whether it forms from coalescing debris in the stellar cloud or whether it so-calls 'clears its orbit'. That was just a political play by the statistical astronomers, who waited until there was barely a quorum to get the new definition passed en catimini. So what if that meant there were more planets found further than Pluto and that Ceres would be classified a planet? How is having 13 or 14 planets so different from having 8 or 9? At least here was a logical, physical-propriety (mass) based definition that could be applied to exoplanets. Right now we have so many exoplanets for which there is no data whether they have cleared their orbit. All we know about them that matters is their mass (big enough to make them spherical) and orbit. If that's enough for them to be considered planets, then why not Pluto and Ceres, etc...