Why is pluto not considerd as a planet any more? Who decided it?

Question

I have heard this is the news and still have not understood why?
Can anyone help?

Answer 1

According to the new definition, a full-fledged planet is an object that orbits the sun and is large enough to have become round due to the force of its own gravity. In addition, a planet has to dominate the neighborhood around its orbit.

Pluto has been demoted because it does not dominate its neighborhood. Charon, its large "moon," is only about half the size of Pluto, while all the true planets are far larger than their moons.

In addition, bodies that dominate their neighborhoods, "sweep up" asteroids, comets, and other debris, clearing a path along their orbits. By contrast, Pluto's orbit is somewhat untidy.

In a move that's already generating controversy and will force textbooks to be rewritten, Pluto will now be dubbed a dwarf planet.

But it's no longer part of an exclusive club, since there are more than 40 of these dwarfs, including the large asteroid Ceres and 2003 UB313, nicknamed Xena—a distant object slightly larger than Pluto discovered by Brown last year.

The new definition also establishes a third class of objects that orbit the sun—"solar system bodies," which would apply to many asteroids, comets, and moons

Answer 2

pluto is a planet still . the body that decides, the classification of objects in the solar system,the international astronomical union(IAU)has no plans to change plutos status as a planet nd has decided against assigning it a minor planet number.Other scientists nd organisations may have different opinions about the clasification of pluto, but the official decision belongs to IAU.
There has been some confusion over this issue because a number of large icy bodies have been discovered in orbits beyond Pluto, in an area known as the Kuiper Belt. These bodies are believed to be hundreds of kilometers in diameter, leading to speculation that still larger bodies (essentially giant comets) exist in this region, including some approaching the size of Pluto. Recent studies of Pluto's composition have also led to the idea that Pluto was once one of these bodies. However, Pluto's chemical make-up and origin don't affect Pluto's designation as a planet (any more than the Earth's make-up and composition would cause us to reclassify it as a giant asteroid.)

Whether these other bodies in the Kuiper Belt will ever be designated as planets remains to be seen.

There is no set scientific law as to what constitutes a planet, but as a rule of thumb, there are three properties of a planet: (1) It must (directly) orbit a star, (2) It must be small enough that it has not been undergoing internal nuclear fusion (i.e. it is not a star or star-like object), (3) It must be large enough that its self-gravity gives it the general shape of a sphere. You might notice that under these rules, the asteroid Ceres could qualify as a planet - I guess we're hedging our bets by calling it a "minor planet".

In the final analysis, the designation of "planet" is more a historical issue than a scientific one. It seems likely that Pluto will always be considered a planet.

Answer 3

The scientists agreed that for a celestial body to qualify as a planet:

* it must be in orbit around the Sun
* it must be large enough that it takes on a nearly round shape
* it has cleared its orbit of other objects

Pluto was automatically disqualified because its highly elliptical orbit overlaps with that of Neptune. It will now join a new category of dwarf planets.

-article about Pluto-
Pluto loses status as a planet

Astronomers have voted to strip Pluto of its status as a planet.

About 2,500 scientists meeting in Prague have adopted historic new guidelines that see the small, distant world demoted to a secondary category.

The researchers said Pluto failed to dominate its orbit around the Sun in the same way as the other planets.

The International Astronomical Union's (IAU) decision means textbooks will now have to describe a Solar System with just eight major planetary bodies.

Pluto, which was discovered in 1930 by the American Clyde Tombaugh, will be referred to as a "dwarf planet".

There is a recognition that the demotion is likely to upset the public, who have become accustomed to a particular view of the Solar System.

Answer 4

It's still a planet, though, there was one recently found that is slightly further from the earth than pluto. The newly discovered planet I think is called Xena/Zena not really sure about the spelling.

Answer 5

Its a moon . A scientist it has no atmosphere is the reason it's a moon.