Why is Pluto no longer a planet?

Question

Should we also worry about Earth meeting the same fate?
Where would we all go???

Answer 1

It is still there, but astronomers have decided that it should not be called a planet because it is too small and in a weird orbit. They always knew it was small and in a weird orbit and there was always some grumbling about calling it a planet and not an asteroid, but recently more small objects in weird orbits far from the Sun have been discovered, and new size measurements have shown that Pluto is even smaller than first suspected. So things just came to a head and all the astronomers finally admitted they were wrong to call it a planet in the first place.

By the way, the same thing happened to Ceres, the largest and first know asteroid. Ceres was considered a full fledged planet for about 50 years after it was discovered (in 1801), but it was finally demoted to asteroid, a name that was made up specially at the time to classify such small objects.

Answer 2

When Clyde Tombaugh discovered it, Pluto just happened to be crossing the "obital disc" of our solar system ( the plane of the ecliptic ). He was looking for another planet along the plane of the ecliptic for a very good reason...that's where you find all the other planets.

Pluto's orbit is offest from the plane of the ecliptic by 17.5 degrees. Sometimes it's as far away as 4.6 billion miles from the sun, and sometimes it's as close as 2.8. It's size isn't really a factor. There's an asteroid (Ceres) between Mars and Jupiter that's almost as big as Pluto, and it's never been considered a planet.

Pluto was lucky do have been discovered at all when it was. Now Pluto will be properly known as the 1st and most famous Kuiper Belt object.

WE LOVE YOU PLUTO!

Answer 3

Okay, so Earth is safe - I don't think you have to worry about packing up your stuff and moving to a new planet.

Pluto is no longer considered a planet because it must meet three requirements:
1. - It must orbit around the sun.
2. - Have a nearly-round shape (I phrased that as simply as I could)
3. - Has cleared the neighborhood around its orbit.

Pluto doesn't meet all of these requirements so it has been downgraded.

Pluto is considered a "dwarf planet" along with two other space objects: Ceres (which is an asteroid) and UB313 (which is an icy space object that is larger than Pluto)

So don't freak - our planet it cool right where it is -

Answer 4

Since the discovery of Xena (unofficial name), orbiting outside Pluto, the International Astronomical Union has finally decided to redefine what it means to be a planet, probably in the expectation of the discovery of more large, distant bodies!
Pluto is now a "dwarf planet" as explained nicely in this BBC article: http://news.bbc.co.uk/2/hi/science/nature/5282440.stm
Its large moon, Charon, has been "promoted" and forms part of a twin body system, since their combined center of gravity lies outside Pluto itself.
The large asteroid Ceres, between Mars and Jupiter, has also been "promoted".
So we now actually have 12 planets: 8 classical and 4 dwarf.
Pluto was always a strange planet, being small and with a highly elliptical orbit. On the new definition, Earth is quite safe and not ever likely to be "demoted".

Answer 5

Pluto is no longer a planet because it was a bad neighbor. It would borrow things and not return them. It would have wild parties with Jupiter and turn the music up all loud at 2:00am. Plus it never took care of its yard. So it had to go.

Answer 6

For the record, Pluto is no longer a Planet only in New York. Every place else it still is, one of 11, or 12 if you count Xena.

Answer 7

They approved new guidelines which define what a planet actually is.

The new definition is: "A celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid
body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."

Pluto is automatically disqualified because its oblong orbit overlaps with Neptune's.

It has been put into a new category of 'dwarf planets'.

Answer 8

Pluto is not a planet because it does not meet the definition of the word "planet". Earth does. and seven other ones. too.

Answer 9

because there are a rather large collection of idiots out there that like to call themselves scientists and they unanimously agreed that it would make better money if they decided to demote pluto. If Pluto is not a planet anymore, then please tell me why It still has its former name? Are they still debating at what would make them more money? They would probably do that for Earth given the chance.

Answer 10

Because the Japanese wanted their own new planets to get promoted and so little Pluto got fired.
No, not if you are nice to astronomers.
Go to Japan.