Note: this topic is from . Thanks ETL.
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Posted on 09/10/2018 6:35:05 AM PDT by ETL
-snip-
The researchers found that the real division between planets and other celestial bodies, such as asteroids, occurred in the early 1950s when Gerard Kuiper published a paper that made the distinction based on how they were formed.
However, this reason is no longer considered a factor that determines if a celestial body is a planet.
“The IAU’s definition was erroneous since the literature review showed that clearing orbit is not a standard that is used for distinguishing asteroids from planets, as the IAU claimed when crafting the 2006 definition of planets,” said Dr. Kirby Runyon, from the Johns Hopkins University Applied Physics Laboratory.
“We showed that this is a false historical claim. It is therefore fallacious to apply the same reasoning to Pluto.”
According to the team, the definition of a planet should be based on its intrinsic properties, rather than ones that can change, such as the dynamics of a planet’s orbit.
“Dynamics are not constant, they are constantly changing. So, they are not the fundamental description of a body, they are just the occupation of a body at a current era,” Dr. Metzger said.
“We recommend classifying a planet based on if it is large enough that its gravity allows it to become spherical in shape.”
“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.”
(Excerpt) Read more at sci-news.com ...
They appear for me when I go to the thread as well a in my comments section. I'm wondering if you're being sensored.
I agree the IAU was wrong in their reasoning, they got it right in the end.
Pluto isn’t a planet. If anything, it’s a large Kuiper belt object, if not just a couple of failed comets.
In reality, the Sun actually only has one Planet, Jupiter. The rest are mere specks in comparison and don’t really count. You can dump all of the extra matter (excluding the Sun) in the solar system into Jupiter and it wouldn’t change things.
Rubbish article.
The new distinction is between major planets and dwarf planets.
The goal of the distinction was to prevent our students from being drowned in ‘planets’
So we have 8 major planets.
And a bunch of dwarf planets - Pluto being the head of the group.
Again, Pluto is still a planet, just not a major planet.
The current list of dwarf planets is:
The five dwarf planets:
Ceres as seen from the Dawn spacecraft. It is the only dwarf planet in the asteroid belt.
Pluto as viewed by New Horizons space probe on July 13, 2015.
Eris and its moon Dysnomia viewed by the Hubble Space Telescope.
Makemake and its moon S/2015 (136472) 1 viewed by the Hubble Space Telescope.
NASA artist’s impression of Haumea.
It’s an excuse.
Note: this topic is from . Thanks ETL.
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Note: this topic is from . Thanks ETL.
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"To Pluto And Far Beyond" By David H. Levy, Parade, January 15, 2006 -- We don't have a dictionary definition yet that includes all the contingencies. In the wake of the new discovery, however, the International Astronomical Union has set up a group to develop a workable definition of planet. For our part, in consultation with several experienced planetary astronomers, Parade offers this definition: A planet is a body large enough that, when it formed, it condensed under its own gravity to be shaped like a sphere. It orbits a star directly and is not a moon of another planet. |
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