Since when did Pluto stop being a planet?

Answer 1

Pluto, the last planet to join the heavenly pantheon, became the first to leave it. The status of Pluto had been under discussion for some time, but with the discovery of 2003 UB313, nicknamed Xena, the question became acute, for it seemingly had as much right as Pluto to be called a planet.

On August 24, 2006, the International Astronomical Union surprised the world by voting in a new definition of planet, one that would exclude Pluto and bring the total number down to eight. (There had previously been been strong speculation that the redefinition would bring the total up to 12 instead of down.)

Pluto was instead classified as a dwarf planet, along with Ceres and the aforementioned Xena. The main difference between a dwarf planet and the real thing is that the dwarf variety has not cleared the area of its orbital path.

This redefinition met with a wave of protests from those who wanted to see the ninth planet grandfathered in, including but not limited to supporters of the late Clyde Tombaugh, who discovered Pluto in 1930. His widow, however, said he would have been accepting of the IAU's decision since "he was a scientist" and understood that astronomers had to take into account newly discovered objects in the Kuiper Belt (where Pluto is located).

But opponents of Pluto's demotion remain unconsoled and have generated a thriving industry in T-shirts, mugs and other memorabilia. Among the many slogans of this movement was one which played on the mnemonic for the names of the erstwhile nine:

Answer 2

It never was a real planet and Scientists have known that for a long time, they just declared it a few weeks ago though. I remember learning in 3rd grade that Pluto doesn't meet any of the planet standards and the guy that discovered it couldn't decide if he wanted it to be deemed a planet. Its funny how so many people are so upset, I think just because they've been taught lies all there lives. My brother and I have been waiting for over 10 years to see when they would finally announce what everyone should've already known. For those that seem so passionate about Pluto and think it should be a planet, what are your reasons? it doesn't have an orbit like all of our planets. It cant sustain itself, and has no gravitational pull, our moon isn't a planet and Pluto is smaller that the moon, only 1/5 the size of it. Pluto's moon is almost the same size as it.

Answer 3

About a month ago scientists finally got together and decided to oust Pluto out of the planetary lineup. They agreed that Pluto did not fit into the catagory of a planet. There are three characteristics scientists look for in an object. If the object fits all three than it it a planet. First it must be round or almost round. Second it must orbit our Sun. Third it must have it's own orbit and not cross into another planets orbit. Pluto crosses Neptunes orbit.

Also there are some scientists who say that because Pluto is so small and made mostly of ice if it were to be closer to the sun it would melt and form a tail therefore becoming more like a comet than a planet.

Pluto has had it's critics since the beginning and while I see their point it's still a little sad to me that my children will only learn about 8 planets in our solar system.

Answer 4

The definition of a Planet was too vague in the past and they didn't know enough about Pluto at the time to say otherwise, so some American that discovered it called it a planet when really it should'nt have been. It has been a topical debate ever since and now with new discoveries of the outer solar system to keep everything else in line, it had to be demoted.

Answer 5

There are three main conditions for an object to be called a 'planet', according to the IAU resolution passed August 24, 2006.

1. The object must be in orbit around the Sun.
2. The object must be massive enough to be a sphere by its own gravitational force. More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium.
3. It must have cleared the neighborhood around its orbit.

Pluto fails to meet the third condition.

The IAU further resolved that Pluto be classified in the simultaneously created dwarf planet category, and that it act as prototype for a yet-to-be-named category of trans-Neptunian objects, in which it would be separately, but concurrently, classified.

Prior to this decision several other definitions had been proposed, some of which might have ruled out planetary status for Earth or Mercury or may have classified several of the asteroids as planets. This version was democratically chosen in a successful attempt at avoiding these non-traditional results.

Answer 6

It stopped being a planet a few weeks ago. I still can't believe it's not a planet anymore. So who cares if it doesn't have any moons? The piont is that Pluto was and still should be a planet.

Answer 7

the scientist that studied the planet made the desicion thatit was too small to be a planet..so they took it off the solar system map...but now it looks like 2 more may have been found..so how knows what these sientists r playing at..but as far as i am conserned who are they to say thats not a planet..it has been a planet for millions and millions of years then one day a few people over a cup of coffee say "you know what...i dont think pluto should be a planet its too small" bloddy sientists...who r they to change something that has been for millions of years.

Answer 8

About 3 weeks ago, also it is not named pluto enaymore, since names are only reserved for planets, pluto is now called asteroid number 134340

Answer 9

about a month ago. Scientists have discovered that it may not actually fit the definition of a planet - so it's no longer a planet.

Answer 10

Not long ago. But when I learned the planets in 3rd grade they were 9... now they are 8 ? Hard to take.....