why pluto is expelled from the group of planets?

Answer 1

behaves more like an asteroid rather than a planet

Answer 2

The new criteria of being able to gravitationally sweep out your orbital neighborhood was added after the discovery of Eris, which is larger. Not the mention the fact that Charon isn't so much a moon as a companion. If Pluto was a planet, then there's no good reason why Eris and Charon and Ceres also shouldn't be planets, and likely thousands of other bodies to be found soon.

Answer 3

Mostly because it is too small. It was believed to be larger than Mars until a few years ago when it occulted a star allowing the most accurate diameter measurement ever, which conclusively proved it is smaller than the Moon. Also, the number of other small objects being discovered out there past Neptune was growing with the possibility of thousands of Pluto like objects being discovered in the next few years, like another asteroid belt, and nobody wanted to have thousands of planets.

Answer 4

because they were thinking of adding more planets to our system, scientists considered redefining a planet. one of the rules of a planet established by scientists is to have a gravitational pull that will someday "sweep out" the smaller objects in its orbital region. this would mean having a gravity strong enough to pull all the things smaller than the moon. guess what pluto failed to do?

Answer 5

allegedly it is too small to be considered a planet and now they are calling it a "dwarf planet"

Answer 6

Its not a planet they say.

Answer 7

because we always pick on the little guy. Who will speak up for the Plutonians and stop this bigotry.

Answer 8

Because they lacked planetary represention during the discussion. Just because they are small doesn't mean they are less.

Answer 9

They always kick the little guy out!!!!

Answer 10

He misbehaved, so we kicked him out.