prove pluto is a "dwarf planet" because of its size?

Question

yes, but it does have enough mass/gravity to form itself into a sphere. correct?

by this it fits into a planet definition.

dwarf planet definition does not give numbers concerning mass amounts (weight)

or am I mistaken

http://en.wikipedia.org/wiki/Pluto#IAU_decision_to_reclassify_Pluto

http://www.sciam.com/article.cfm?chanID=sa006&articleID=93385350-E7F2-99DF-3FD6272BB4959038&pageNumber=2&catID=2

Answer 1

TOUGH challenge.... pluto's radius is 1,195 km, eris' radius (a larger dwarf planet) is 1,200 ± 50 km. earth;s radius is 6,371.0 km (approximately). since eris was discovered after pluto, and both have characteristics that question whether or not it coudl be called a planet, it was 'demoted' to dwarf planet. a controversial decision, but probably the best decision considering

A planet, as defined by the International Astronomical Union (IAU), is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, not massive enough to cause thermonuclear fusion in its core, and has cleared its neighboring region of planetesimals

a dwarf planet is a body in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (near-spherical) shape, has not cleared the neighborhood around its orbit, and is not a satellite

this is only PROOF based upon the widest-accepted planetary definitions. not everyone accepts them, so perhaps nop proof is possible

no i daresay you are correct. but an object only meets a definition in this case if all the parts apply. the key to eris, pluto & ceres NOT being planets is that they have not cleared the neighborhood in their orbits of other bodies.

the real question still at large in the astronomical community is how a body can be a planet, and then after decades not be one? should pluto be 'grandfathered' in? i am of two minds there, and while i tend to reluctantly agree with the IAU, i still feel as if dr tombaugh has been slighted somehow

Answer 2

there was also something about accreting most of the objects around it and I don't remember it all and then I think the def was changed. Even the man that discovered Pluto said it was not a planet. It's a Kuiper belt object and there are lots of others out there.
And as far as Pluto being a planet or not. As more bodies are discovered, it is necessary to redefine what little was know. I think we can all grasp the idea that Pluto is a dwarf planet now. No wonder science changes so slow. . .

Answer 3

planet or dwarf....what is the difference ?
i mean we shouldnt care about it at all, there are more aspects that we should care about a planet..."dwarf planet" is just a name...but if you are concerned about classifications then i have to say , i dont like the term "dwarf".... it has been a planet for many years and i think they should bring up an exception this time...

Answer 4

compare it to Uranus