Does it matter whether we call Pluto a planet? If so, why?

Question

Astronomers have been debating whether it ought to be reclassified as a "minor" planet in the same way as objects like Ceres and Vesta

Answer 1

Are you kidding? There are hundreds of Star Trek episodes on the line here!!

ONce again, I think that the word "planet" is about as useful as fur string bikini. It seems that there are several round massive objects orbiting the sun. They are diverse in composition and nature and it's time that we acknowledge that.

Pluto, Earth and Jupiter have about as much in common as well, the planet Pluto and the disney character... Designation only. So how scientist want to designate Ceres and Pluto as a "Pluton" makes little sense.

I say split the solar system up into categories based upon composition. Mercury, Venus, Earth, Mars and Ceres have a rocky crust, mantle and at one point, all had molten cores. These are your "Terresstrials." Jupiter, Saturn, Uranus and Neptune are so light in density, that if you had a chunk of them, they'd float in water!! They have several moons and most of them have rings. These are your "Jovians" or Gas Giants. Pluto, Charon and Xena are as far as I'm concerned, glorified snowballs. Yet, they are round and have moons orbiting them as the sorbit the sun.... If they were closer to the sun, they would grow tails like any other comet, but they don't get that close and they take 200+ years to orbit the sun. These are your KBOs or call these the Plutons.

I think it's easier to categorize the solar system this way and it actually makes it easier to understand what these things are instead of using useless acronyms to pass a school test. I hate using arbitrary size specifications to say "this is a planet, this is a minor planet and this is a giant planet." It's arbitrary and bnased upon human criteria. How can so called scientist be so stupid? Our job is to observe nature, not to try and make it up.

Answer 2

The question isn't so much regarding Pluto as it is defining our language better. Planet, by definition, was too vague for someone to not confuse it with other things. Kind of like calling a "tree" simply a "plant". While a tree is a plant, it's not very descriptive. And a tree and a rose are too very different things...and don't smell the same (to contradict another answer on this thread).

So now, the word "planet" can distinguish the difference between an asteroid, a Kuiper Belt Object, a Comet, a meteroid, a moon, etc...

And for those that have trouble remembering that there are 9 planets (and now a total of 12) in our solar system, you might try practicing some simple memorization games. If people can remember the stats of hundreds of baseball players over many decades, I'm sure they can handle the names of a few planets.

Answer 3

For thousands of years very little was known about the planets other than that they were objects that moved in the sky with respect to the background of fixed stars. But today, hosts of newly discovered large objects in the outer regions of our solar system present a challenge to our historically based definition of a "planet."

At first glance, one would think that it is easy to define what a planet is - a large and round body. On second thought, difficulties arise. Where is the lower limit? How large and how round should an asteroid be before it becomes a planet?

The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919. As a result, it convened the Planet Definition Committee that crafted the new definition.

Basically scientists just wanted to be clear on what exactly Pluto constituted.

Answer 4

it always matters what terminology someone uses. words have be be defined or they are useless as a means of communication. the international astronomical union seems to be defining planet as any body who's mass is more than about 5 x 10+20 kg, so it is spherical, orbits a star, and has less mass than a brown dwarf. i think i can accept this definition. this new definition also requires that an asteroid, ceres, and pluto, charon, and 2003 UB313 will all be planets. pluto, charon, and 2003 UB313 will be called plutons.

look here:
http://www.iau2006.org/mirror/www.iau.org/iau0601/iau0601_release.html

Answer 5

I think it matters, as some answerers have pointed out, but not to science. Trekkies will care because all those past episodes have suddenly become dated. Publishers will care because they can revise and sell updated science books. And on and on...it will matter to some people, but it will not change science.

Pluto is still Pluto, Charon is still Charon, and the unforgetable 2003 UB313 is still ... Their physical and chemical characteristics will not change because of a status change.

I tend to believe that, if there is a debate over choosing one thing over another, it does not matter to science. Why? Because if it mattered, whatever it might be, there would be no debate over it. There would be consensus.

Because all this status change stuff came after long and wrangling debate, it does not matter what status you give these solar bodies. If it did matter, there would not have been the debate.

Answer 6

I wouldn't think it would really matter, it's still a ball of rock and ice no matter what anyone calls it.

I wish they would make these planets:
Sedna discovered 2003, Ranges from 7 billion to 90 billion miles from the sun, Diameter is 600 - 1100 miles, Orbital period is 10,500 years, Coldest body in the solar system at -400 F.

DW2004 discovered 2004, Distance from sun 4.4 billion miles, Diameter 1000 miles, Orbital period 250 years.

Quaoar discovered 2002, Distance from sun 4 billion miles, Diameter is 800 miles, Orbital period is 285 years.

Answer 7

I THINK IT IS IMPORTANT NOW TO DEFINE PRECISELY WHAT A PLANET IS. UNDER THE GREEKS IN DAYS YONDER, A PLANET SIMPLY MEANS A WANDERER. THE PLANETS ARE THE ONLY "STARS" TO WANDER IN THE SKY, UNLIKE THE OTHER STARS.

THE PROBLEM NOW IS, THERE ARE JUST TOO MANY OF THESE OBJECTS ARPOUND IN THE SOLAR SYSTEM. SO HOW DOES SCIENCE CLASSIFY THEM?

IT IS EVIDENT NOW THAT PLUTO IS SMALLER THAN THE 10TH PLANET, XENA. SHOULD SCIENCE STILL REGARD IT AS A PLANET. IF IT DOES, WHAT ABOUT THE NUMEROUS OTHER KUPIER BELT OBJECTS THAT ARE YET TO BE DISCOVERED. HOW DO WE CLASSIFY THEM?

ANOTHER PROBLEM TO ARISE IS THIS. IF PLUTO WERE TO BE DISCARD FROM THE PLANET CATEGORY, WHAT ABOUT THE INNER PLANETS? THEY, COMPARED WITH THE OUTER PLANETS ARE JUST AS DIFFERENT. THEY ARE ROCKY PLANETS WHILE THE OUTER PLANETS ARE BASICALLY GASEOUS.

WHAT IS NEEDED NOW IS A PRECISE DEFINITION OF WHAT A PLANET IS.

Answer 8

It matters what kind of astral body we class as a planet simply because everything need a category, go to small and you will be calling a rock floating in space a planet but I believe they class a planet by whether it's mass is great enough for its own gravitational pull to make it into a spherical shape or near spherical anyway
hope this helps
cheers
Chris

Answer 9

yeh - its kind of an on-going debate. no one can be sure for certain at the moment. i think you just pick whether you beleive its a planet or not. it has various signs to show that it is not actually a true planet, such as:
- it would beciome a comet if it moved v. close to the sun.
- it has a v. elliptical orbit
- it is in a twin orbit with its moon Charon.

omg, i can't believe i remember that all from my Astronomy GCSE lol.

Answer 10

I thought that had been decided a long time ago like about 1930. What difference does it make any way. It is just another piece of debris floating around. I guess people have to find a place for everything and give it a title.