why pluto is no more a planet?

Question

there was an meeting of scientists about deciding tht they have to considard pluto a planet or not. So they dicided tht pluto is no more a planet. Why?

Answer 1

The International Astronomical Union decided that Pluto was no longer a planet. The reason is that while Pluto is round, orbits the sun, and has three moons, it has not cleared (via gravity) its own orbit of debris. Instead, they decided to classify it as a "dwarf planet".

See the details below.

RESOLUTION 5A
The IAU therefore resolves that "planets" and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:

(1) A "planet" [footnote 1] is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape [footnote 2] , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects [footnote 3] except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".


Footnote 1: The eight "planets" are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Footnote 2: An IAU process will be established to assign borderline objects into either dwarf planet and other categories.

Footnote 3: These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

RESOLUTION 6A
The IAU further resolves:

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.

Answer 2

The final nail in Pluto's coffin was the discovery of Eris, the so-called 'tenth planet'. Eris is larger than Pluto and scientists decided not to call either of them planets

Answer 3

The International Astronomical Union (IAU), the official scientific body for astronomical nomenclature, defines a "dwarf planet" as a celestial body that, within the Solar System:

(a) is in orbit around the Sun;
(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape;
(c) has not cleared the neighbourhood around its orbit; and
(d) is not a satellite

The term "dwarf planet" applies only to objects in the Solar System and is quite distinct from "planet" and "small solar system body".

from Wikipedia, the free encyclopedia.

According to that it was reclassified as a 'dwarf planet'.

Given reason: It has not cleared the neighbourhood around its orbit.

Answer 4

Pluto has never really been a planet. It is too small, not round enough, has a very elliptical orbit, and is unlike all the other planets.

Answer 5

You answered your own question. Because these almighty scientists decided it was no longer a planet. Like it really matters, what they think.Pluto will go on as usual.

Answer 6

this is easy pluto is no longer a planet because pluto is to small to be a planet like other planet are way bigger than them like imagine your the smallest thing in the world do you think you could be that thing forever? no well you ask quite easy things.....

Answer 7

because its mass is nearly equal to its moon Cheron, neither of which is half the size of mercury.

Io(jupiter) is not concidered a planet either because it orbits a larger body

pluto and Cheron orbit eachother, and so no planet status for either

Answer 8

Cause the name is taken by a dog.

Answer 9

That becouse it don't move in lts specific track ..