Should scientist have ruled out Pluto as a planet?

Answer 1

I really don't know.

Just as a progression of discovery, Pluto came at a time when it was unique in our solar system. Had Pluto not been discovered until this year, astronomers would not have classified it as a planet, but rather as a Kuiper Belt Object. KBO's are similar to asteroids in that there is a swarm of them orbiting the sun in a particular area of our solar system.

Times have changed since 1931.

When the first asteroid, Ceres, was discovered it was immediately called a planet. Within a few years several more asteroids were discovered and it became apparent they were a special class of bodies. Ceres was demoted lest we quickly add dozens or even hundreds of "planets" to the list. Same issue with Pluto, how can we include it as a planet and yet not dozens of other similar planetesimals? Or do we greatly expand the list of planets?

The problem with Pluto is that it was discovered decades before other KBOs were found, so its status as a planet became ingrained in our culture. Should scientists have ruled it out? Maybe, maybe not...and not all scientists agree. The debate may not be over.

Answer 2

They are the ones who originally ruled in in as a planet, so if anyone has the right to rule it out, they do. New information became available and they changed their minds. The new information is that last year Pluto passed in front of a dim star allowing astronomers to measure its size more accurately than ever before, and it is much smaller than once thought; smaller than the Moon. Also, other objects only slightly smaller were discovered, and they needed a definite dividing line between the smallest planet and the largest asteroid, and poor Pluto, at its newly known small size, just did not qualify as a planet!

Answer 3

well...yes
Pluto contains more ice then rock, and it's satellite Charon seems to have a higher density, so Charon is the planet and Pluto is the satellite, but they are so similar that you can call them "double planet."

However there are "rocks" in our solar system that are farter then Pluto and bigger too ! For example Eris.

Ceres that is in the Asteroids belt is quite big too, and very similar to Pluto, so why don't call it planet too ?

So there is the story :
From 1930 to 2006, Pluto (), the largest known Kuiper belt object, was considered the Solar System's ninth planet. However, in 2006 the International Astronomical Union (IAU) created an official definition of the term "planet".[3] Under this definition, Pluto is reclassified as a dwarf planet, and there are eight planets in the Solar System. In addition to Pluto, the IAU currently recognizes two other dwarf planets: Ceres (), the largest object in the asteroid belt, and Eris, which lies beyond the Kuiper belt in a region called the scattered disc.

Answer 4

i hated that they ruled it out. i loved pluto. i had a really cute name. but they say to be a planet, a heavenly body should revolve around the sun and not around another planet. pluto crossed orbits with neptunes you see.