Is pluto really not a planet? is anyone else shocked and saddened by this?!?

Question

How come the people of the world didnt have a say in deciding whether or not it is a planet?

Answer 1

Did the people of the world have a say in the naming of the radioactive chemical elements Uranium Neptunium and Plutonium? Same three gods as the outermost three planets discovered and named since telescopes augmented human eyesight in scouring the heavens.

It is not practical nor is it appropriate to involve six and a bit billion people in the decision, Mainly because, logistics aside, they don't know the context of how many objects the Solar System is now known to be teeming with and the pace of discovery of extra-solar planets and asteroid belts. Which the IAU do know about and so the IAU are better able to decide upon how to categorise various bodies in view of their similarities to and their differences from one another.

This is an exercise in scientific classification and no different in kind from deciding to classify Indian and African elephants as two different species and later to develop a sub-species within those species when the evidence warrants doing so. It is a technical, specialist thing.

So grieve by all means but a sense of bereavement will not last and you will come to terms with why it was done if you find out more about it.

Pluto hasn't gone anywhere, it just got reclassified as a dwarf planet along with Ceres Charon, Xena and a dozen others, mostly Trans-Neptunian Objects like Charon and Xena, but three of them are, like Ceres, asteroids lying between Mars and Jupiter.

There is understandable dismay at Pluto being demoted in status but people need to understand the reasons the IAU had to grapple with definitions and categories at this time,:

(1) in 1930 we knew of just one body lying beyond the orbit of Neptune. Now we know of more than 1000

(2) we are discovering asteroids at a rate of 5000 a month

(3) we now know of 200+ extra-solar planets orbiting 170+ other stars, some of which we now know to have asteroid belts

It is conceivable the IAU may create more categories in the future in the light of more discoveries, The moment we find an extra-Solar System planet with extra-terrestrial life on it, for example, I would expect Habitable Zone Planet to be a new category and only Earth and Mars to be in it.

We already have the distinction between terrestrial planet (the inner 4 planets) and gas giant (the outer 4 planets) and are assessing new extra-Solar-System planets in the light of that distinction and a new category name for the informally-named "hot Jupiters" (i.e. large planets orbiting near to their star at less than 1 AU distance) of which we know several, may not be far away,

As science expands its knowledge, it needs more concepts and categories with which to describe that knowledge, That is perfectly normal and should neither surprise nor alarm us,

Creating new categories and reclassifying known objects in the light of them has happened before: in the 19th Century when the number of planets was pruned from 11 to 7 out of concern that being consistent and admitting other, newly discovered bodies to the planetary club that were similar to the ones they chose to kick out instead would have meant the number of planets could rapidly start to escalate and mushroom out of control,

To understand what is going on now, it helps to understand what went on then,

The number of bodies in the Solar System known to astronomers has been burgeoning for a long time now, but the general public seems unaware of this, given the way people blithely talk of Ceres (discovered 1801) Charon (discovered 1978) and Xena (discovered 2003) having "just been discovered", And given how one Yahoo answerer recently confidently asserted that Ceres, Charon and Xena were all "newly formed"!

(I wish people wouldn't make up astronomical theory on the hoof like that! The gullible will only go and repeat such Malapropisms as gospel truth!) (Gossip-tell truth would be a more apt description,)

There was a similar definitions crisis in the early 19th century and again in the mid-19th Century as the number of known objects in the Solar System started to grow and grow,

By 1807 the 8 Solar System bodies known to classical astronomy (the Sun, the Earth, our Moon and the 5 classical planets known from antiquity, Mercury, Venus, Mars, Jupiter, and Saturn) (1 star, 6 planets, 1 moon) had grown to 26. Uranus was found in 1781 making 7 planets. There were 4 Jovian moons, 7 Saturnine moons and 2 Uranian moons, 14 in all

And then there was the discovery of the first four asteroids. These were 1 Ceres on January 1, 1801, 2 Pallas on March 28, 1802, 3 Juno on September 1, 1804, and 4 Vesta on March 29, 1807,

What were astronomers to call these new objects? They weren't moons as they rotated around the Sun, so they had to be planets, didn't they? As there was, initially, no other category but moons or planets to put them in.

After 2 Pallas was discovered though, Sir William Herschel (the discoverer of Uranus) coined the term "asteroid" meaning "star-like"), in 1802.

But Ceres was meantime assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno and 4 Vesta) for about half a century until further asteroids were discovered.

So we now had 1 star, 11 planets and 14 Moons, the beginnings of a distinction between major and minor planets and a sense of unease as to what we would do if more asteroids were discovered as the first four were all disappointingly small in size, so did they really belong in the planetary club? (Similar doubts were expressed about Pluto, right from the outset in 1930,)

38 years pass and then in 1845 the asteroid 5 Astraea is discovered and on September 23, 1846 the planet Neptune and a mere 17 days later on October 10, 1846, Neptune's moon, Triton. (We now have 1 star, 12 Planets 15 Moons and 1 non-planetary Asteroid.)

The pace of discovery then starts to really hot up. Four more asteroids in nine months: 6 Hebe on July 1, 1847, 7 Iris on August 13, 1847, 8 Flora on October 18, 1847, and 9 Metis April 25, 1848

Then on September 16, 1848 an 8th moon of Saturn called Hyperion is discovered,

Plus a further 6 asteroids are found in just over two years: 10 Hygiea on April 12, 1849, 11 Parthenope on May 11, 1850, 12 Victoria on September 13, 1850, 13 Egeria on November 2, 1850, 14 Irene on May 19, 1851 and 15 Eunomia on July 29, 1851.

And on October 24, 1851 a 3rd and a 4th moon of Uranus: called Ariel and Umbriel were discovered.

So now we had 42 objects: 1 star 12 planets 18 moons and 11 asteroids. If the latest asteroids were all to be regarded as planets, making a total of 23 planets (and 10 Hygiea was bigger than 3 Juno, just like Xena is bigger than Pluto), it was likely to start getting silly (by 1868 the number of asteroids was to rise to 107 and Victorian schoolchildren would have needed a massive 115-word mnemonic to remember all the names).

The unease grew to a crisis, a redefinition was clearly necessary and an inevitable decision was taken to regard all 15 asteroids as a separate category from planets and Ceres, Pallas, Juno and Vesta were kicked out of the planetary club, just like Pluto has been kicked out now.

There are some clear parallels between the situation in the 1850s and the situation now, Four under-sized runts had obtained planetary status, with seemingly more to follow as they were discovered, creating an overwhelming feeling among astronomers that the currency would be devalued if all these further objects were to then be automatically awarded planetary status. So they cried Whoa! And called a halt. And created a new category, Just like the IAU has now done,

SO HOW MANY OBJECTS HAVE WE GOT IN THE SOLAR SYSTEM NOW?

Stars: 1

Planets: 8

Moons: over 80 known moons of the dwarf planets, asteroids and other small solar system bodies.

(The asteroid 87 Sylvia has 2 moons for example as does the Kuiper Belt Object KBO 2003 EL61.)

AND another 162 moons orbiting around planets: Mercury has none, Venus has none, Earth has 1, Mars has 2, Jupiter has 63, Saturn has 56, Uranus has 27, Neptune has 13.

Kuiper Belt Objects: over 800 (all discovered since 1992).

Trans-Neptunian Objects: over 1000 (includes the 800+ KBOs) i,e, there are 200+ in the Scattered Disk and the Oort Cloud.

Asteroids: Hundreds of thousands of asteroids have been discovered within the solar system and the present rate of discovery is about 5000 per month. As of July 23, 2006, from a total of 338,186 registered minor planets, 134,339 have orbits known well enough to be given permanent official numbers. Of these, 13,242 have official names.

Current estimates put the total number of asteroids above 1 km in diameter in the solar system to be between 1.1 and 1.9 million

So you can see

(a) why some definitions are needed and why reclassification is necessary

(b) how totally unaware of the state of scientific knowledge the general public is and how uninformed people are when they get excited at tales of "3 new planets being discovered" and wonder if there might perhaps be more where those came from,

Finally, these issues need to be seen in the context of the 205 extra-solar planets we now know to exist and the asteroid belts that have now been detected in some of those stellar systems,

Consistency being a desirable thing to achieve in science, whatever definitions and categories the IAU now adopt, they need to be applicable to every star with other objects in orbit around it, throughout the entire universe, That is the context in which Pluto's status is now being discussed,

Answer 2

They have to have a system to decide on what is a planet and what isn't. Otherwise you'd have people saying that everything in space is a planet and people saying there is only Earth as a planet etc.

Therefore, if there is found to be a fault in the system, it needs to be corrected.

This is how I believe the people who decided to not class Pluto as a planet anymore may have thought.

I don't know, I'm just trying to see their point of view.

The other side's point of view, the one you seem to be on, seems to dislike the change maybe because it is confusing and you would find it easier if we decided one system and that was the end of that.

On the whole, I think that every now and again the system does need to be reviewed and changes need to be made if necessary. Am I the only one here who thinks this?

Answer 3

In science, it is necessary to classify things according to their properties so that when discussing phenomena and new discoveries everyone understands exactly what it is. Pluto doesn't fit the new description of what a planet is, so it got demoted to 'dwarf planet'. This new category of 'dwarf planet' gives scientists an extra word to describe objects in space that previously didn't have a classification.

This way, when they are talking about smaller objects with irregular orbits, and not enough gravity to make it a sphere they all know that is what they are talking about, instead of having to say 'we've found a planet with irregular...'

Answer 4

I believe it isn't since the new descovery says so, but i like the idea of grouping pluto and the pluto-like findings as Dwarf planets, it's a better description for the former planet now.

Answer 5

Pluto is not bothered about what we call it.Pluto is pluto.If some life is there in Venus and they call earth as not planet will it affect us?If you put to scientists in a room and lock,when the door is opened they will come out with three opinions or theories.

Answer 6

It's not a huge tragedy, just the inevitable consequence of improvements in scientific instruments in the 70-odd years since Pluto was discovered. At the time, there were few other comparable objects that were visible - now there are more and we're able to create a new classification for them.

Answer 7

Astronomers and others need to figure out the proper definition of a planet,moon,star ect. It might be a few years but I think Pluto will eventually get it's vendication and prove all theese astronomer bozos wrong.

Answer 8

It is now not a planet...

I asked this question a week ago and everyone said it was still a planet, except for one guy who told me it would be decided in Chec. That was the only person on yahoo answers that even came close to the right answer. Now pluto was demoted to a sub-planet along with ub-233.

Whats next Mars...
for the record I new this was coming.LOL

Answer 9

This is another example of the 'powers that be' removing yet another traditional plank on which our lives are built. They clearly have forgotten the phrase 'if it ain't broke, don't fix it'.

What difference would it have made if they used their new definition to cover new types of planetoids and bodies and left Pluto among the 'classical' planets?

They want to unsettle us because unsettled people are easier to manipulate and control. We should simply refuse to accept the redefinition of Pluto itself.

Answer 10

I am saddened but not shokced. Given all the evidence a lot of us have been dismissing it as a planet for years.

Answer 11

Great, now we have to start a "I'm so sad Pluto got de-listed" support group.
And classify the depression and Plutotitis.
and according to severity,Plutotitis A, B or C.........