"Researchers Say the Reason Pluto Lost Its Planet " Topic

…Status is Not Valid.

"In 2006, the International Astronomical Union (IAU) established a definition of a planet that required it to clear its orbit, or in other words, be the largest gravitational force in its orbit. Since Neptune's gravity influences Pluto, and Pluto shares its orbit with frozen gases and objects in the Kuiper Belt, that meant Pluto was out of planet status. However, in a new paper published August 29 in the journal Icarus, Florida Space Institute researcher Philip Metzger and co-authors reported that this standard for classifying planets is not supported in the scientific literature.

Dr. Metzger and his colleagues from the Planetary Science Institute, the Southwest Research Institute and the Johns Hopkins University Applied Physics Laboratory reviewed the scientific literature from 1801 to the present.

They found that William Herschel's 1802 paper is the only case in the literature that used the clearing-orbit requirement to classify planets, and it was based on since-disproven reasoning…"
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Amicalement
Armand

I don't care. Pluto is still a planet to me. And a dog.

Dan

And a god with a hot wife.

I suspect the "clear its orbit" criteria was disingenuous anyway. They realized that there were definitely two, certainly a dozen, probably dozens, and maybe thousands of objects like Pluto in that zone, and no one wants there to be a thousand planets, only eight of which are not ice balls in the Kuiper Belt. So Pluto had to be kicked out, so they invented a justification.

Really, we should have redefined "planet" as soon as we figured out how different Mars and Jupiter were. Once Copernicus figured out the solar system the word "wanderer" was obsolete, and once you realize that Jupiter is not the same sort of thing as Mars it's time for new words.

"Gas Giant" is dumb, too. Giant what?

If we had come up with new vocabulary for terrestrial planets and gas giants back when we should have the whole Pluto fracas would have been obviated. Then when we discovered Pluto we would probably have put it in the terrestrial planet category, but fewer people would have minded when we re-classified it as an ice ball.

But instead we will be fighting about this silly, silly distinction for at least another decade. Pluto does not care what we call it. It doesn't have a different legal status based on this classification. It matters not a whit what we call it. What does it say about us that we keep bickering over this? Do we really believe that how humans refer to these things matters?

"And that's not just an arbitrary definition. It turns out this is an important milestone in the evolution of a planetary body, because apparently when it happens, it initiates active geology in the body."

"Pluto, for instance, has an underground ocean, a multilayer atmosphere, organic compounds, evidence of ancient lakes and multiple moons," he added.

"It's more dynamic and alive than Mars. The only planet that has more complex geology is the Earth."

So I guess that makes a lot of Jupiter's and Saturn's moons "planets" as well.

And a god with a hot wife.

A wife he kidnapped and raped

A wife he kidnapped and raped

Those Greek/Romans loved to party.

(smile)

Amicalement
Armand

Any definition that makes Pluto a planet makes the total planet count jump into the mid teens immediately. Most astronomers were fine with that, but oddly enough there is a group of people that want 9, and only 9, planets. They fought to exclude the other kpo's but couldn't come up with a definition that didn't also exclude Pluto, and in the end this intransigent group was more willing to live with 8 planets, rather than 20+.

There will be reluctance to go with Pluto as a planet, because "we" are actively searching for Planet Nine.
Sorry, but that's Pluto.
Then there's Edna and Phwroar and Gargle. And of course Ceres and all those lovely moons.

Can't call Planet Nine Planet X either. That's already taken, and not for the good.
Call it Planet Odin. Is Loki taken? Thanos? Have any problem with Marvel Supervillains?
Problem solved. Now all God's Children that are round can be called planets. I'm good with that.

I would bet a beer and pizza that sticking with Nine planets is imbedded in astrology.

Yeah, the discovery of more planets makes astrology look even more ridiculous than it already does, if that were possible.

I've never had a problem with adding more planets, and the definition is simple: round due to its own gravity and not undergoing fusion (or having done so in the past). Thus, planet. The distinction between planets and moons is secondary, based on an object's orbit around a central mass, but otherwise, yes, a planet in its physical makeup can also be a moon in its orbital movement. (The Moon originally was one of the "planetes", or "wanderers" in Greek astronomy.)

Time to learn to count higher and drop the pizza mnemonic.

Beer and Pizza… Hummmm!….

Amicalement
Armand

Yeah, the discovery of more planets makes astrology look even more ridiculous than it already does, if that were possible.

Astrology doesn't need any such help.

the definition is simple: round due to its own gravity and not undergoing fusion (or having done so in the past). Thus, planet.

You're purposely leaving out another qualifier for the current definition of planet. Science changes and definitions change. Like you, I also grew up with Pluto as the 9th planet. But I don't have an emotional attachment to that fact.

I also grew up with Brontosaurus being a dinosaur. Now it's a genus, together with Apatosaurus, all within the sub-family Apatosaurinae. Things change as new information is available.

The Moon originally was one of the "planetes", or "wanderers" in Greek astronomy

That doesn't mean the Moon is a planet. The "wandering" only is a description of the erratic orbits in the incorrect context of a geocentric solar system. The "wandering" was explained correctly by Copernicus