Question Is there a 9th planet? If so, then how big, dense, and massive is it? What is its orbit around the sun and gravitational effect on the Solar System?

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Does Planet 9 exist?

  • yes

  • no

  • probably

  • not sure


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Jan 29, 2020
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Question. Is it possible such an arrangement in which planet x will create a solar eclipse, but at the same time will not cause strong cataclysms on the earth with its gravity? Some seismic activity is acceptable. If it were possible, we would receive historical evidence.
 

Catastrophe

The devil is in the detail
OP #1 "Please give distinctive details of your vision of planet 9 and try to name it."

For a solar eclipse you would have to place "planet X" between Earth and Sun, so it could be done if you place it inside Earth's orbit. Depending on its size, it could disrupt the inner Solar System.

It is an open question since OP offers you any choice of "your vision".

Cat :)
 
Jan 29, 2020
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Thanks. As far as I remember, Pluto is sometimes closer than Neptune. Maybe something like this? Perhaps there is no destruction, since there is no convergence due to resonance. Simply, if possible, it could explain both the Star of Bethlehem and the unauthorized eclipse during the crucifixion of Christ. It is known that if the dating is correct, then there could not have been an eclipse at that time. However, one apocryphal text says that the eclipse was exactly "as usual."
 
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Is it necessary to become attached to this period? Perhaps at the initial stage, the passage of this body was catastrophic and created a mass of asteroids and comets that remain to this day. This led to constant collisions, but gradually they became less and less frequent and the trajectory of the earth does not intersect with this planet.
 
Jan 29, 2020
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One more question. There is a rationale in Sitchin's theory. He said - at the site of the asteroid belt there was a water planet, which the planet x collided with. Part of the water planet became the earth and part of the asteroid belt and comets. This is indicated by a depression in the Pacific Ocean and a lot of ice in space. But at the same time, the planet x itself all the time returns to the asteroid belt.

Personally, I do not see a special hole in the asteroid belt for this planet. And it's strange that planet x can remain in its original orbit after the collision.

Is it possible to assume this - when colliding with a water planet at the site of the asteroid belt, planet x passed between this and the sun. Because of this, x dropped its speed and began to pass closer to the sun and also pulled the rest of the water planet earth into its current orbit? Perhaps it was originally orbit of the moon, which became a satellite. This ensures that the uniform distribution is not disturbed.
 
Nov 10, 2020
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I think moons do clear their orbits, if I understand your direction here. Are there any moons that have the same orbit? I know there are some moons that come close, one pair even swap orbits when the inner orbiting moon catches the outer one.


I give Brown and others credit for making the efforts to help get new and improved definition to "planets". Others, I know, don't agree but I don't dislike sentimental mindsets.
Regarding moons co-orbiting Tethys happens to have two trojans Telesto at its L4 and Calypso at its L5 Lagrange point with Saturn and likewise Dione has its own pair of trojan moons Helene at L4 and Polydeuces at L5 the latter of which is in a tadpole orbit as well.

Incidentally with regards to why Saturn's system has so many exotic orbital configurations recent research based off the Cassini mission's grand finale and observations of the changes in the orbits of Saturn's moons and the planets ring system find that both Saturn's rings the orbits for most of Saturn's moons are still dynamically "young" not yet having had time to reach a stable equilibrium configuration and there is limited evidence for any past resonances which could have stabilized the system. Current observations seem to best support the major moons of Saturn co-forming with the planets ring system around a billion years ago. Prior to this Saturn likely had little to no axial tilt however the ongoing tidal interactions with the planet and its moons and ring system are currently still tipping Saturn over a process which shows no signs of slowing anytime soon. At some point in the future these trojan moons are likely to collide with their respective primary moon and new moons continue to form from Saturn's outer rings. Titan is also destabilizing some of the moons orbits particularly in the case of Hyperion

After Mars, decreasing size of objects in the Solar System are:

Ganymede (moon of Jupiter)
Titan (moon of Saturn)
Mercury (planet)
Callisto (moon of Jupiter)
Io (moon of Jupiter)
Moon
Europa (moon of Jupiter)
Triton (moon of Neptune)
Pluto (dwarf planet)
Eris (dwarf planet)

Sometimes the last two are reversed. After that it is all moons and asteroids for quite a while: Haumea, Titania, Rhea, Oberon, Iapetus, Makemake, 2007 OR10, Charon, Umbriel, Ariel, Dione, and so on. You may find the order of these differs as, as you go down the list, the smaller the differences and the more subject to change.
Eris and above are all fairly spherical, as is Titania, but Haumea is definitely not. Rhea and Oberon are rounded, but Iapetus is rather oblate. After these, more will be less rounded.

Cat :)
Yep there is actually a pretty big gap between these objects and the next largest dwarf planet or moon personally I have always felt the greater degree of differentiation and more substantial masses would serve as a good distinguisher between these bodies and the smaller less spherical bodies
Probably worth noting that if ranking by mass this list doesn't really change much aside from Mercury moving ahead of Ganymede while being just behind Mars and Eris swaps places with Pluto as Eris is a bit more massive while Pluto is a bit larger i.e. less dense. Most of the smaller rounded bodies than Pluto and Eris have for the most part cooled below hydrostatic equilibrium even if they once were in equilibrium which is another factor which makes this a fairly good cut off if size and mass aren't enough. Its all a matter of semantics where you chose to draw the line but I would prefer some recognition of the distinctiveness of Pluto and Eris relative to other dwarf planets particularly with regards to their large eccentricities and orbits which are indicative of being tossed out into the Kuiper belt by Neptune's migration
 

Catastrophe

The devil is in the detail
"Yep there is actually a pretty big gap between these objects and the next largest dwarf planet or moon"
I am not sure what you mean by that. My impression is that they all clump up together, very often with changes in order. On that basis I will continue the list, but please don't tell me there are errors. The order keeps changing with new/improved/whatever measurements:

After,
Haumea 1960 km
Titania 1577 km
Rhea (Saturn V) 1527 km
Oberon (Uranus IV) 1523 km
Iapetus (Saturn VIII) 1468 km
Makemake (136472) 1440 km
2007 OR10 (225088)
Charon (Pluto I)
Umbriel (Uranus II) 1169 km
Ariel (Uranus I) 1158 km
Dione, (Saturn V) 1123 km it continues
Quaoar (50000) 1070 km
Tethys (Saturn III) 1062 km
Sedna (90377) 995 km
Ceres (I) 934 km / 952 km / 914 km take your pick
2002 MS4 (307261)
Orcus (90482) 917 km
Galacia (120347)
2002 AW197
Varda (174567)
2013 FY27 (532037)
2003 AZ84 (208996)
Dysnomia (Eris I)
Ixion 650 km
Enceladus (Saturn VI) 504 km
Miranda (Uranus IV) 471 km
Porteus (Neptune III ) 420 km
Mimas (Saturn VII) 396 km
Hyperion (Saturn VIII) 360 km
Nereid (Neptune II) 340 km
Amalthea (Jupiter V) 250 km
Phoebe (Saturn IX) 213 km
Janus (Saturn X) 203 k
Larissa (Neptune IV) 194 km
Galatea (Neptune VI) 176 km
Himalia (Jupiter VI) 170 km
Puik (Uranus XV) 154 km
Sycorax (Uranus XVII) 150 km
Despina (Neptune V) 148 km
Portia (Uranus XII) 135 km
Thebe (Jupiter VII) 116 km
Elara (Jupiter VII) 80 km
Thalassa (Neptune IV) 80 km
Naiad (Neptune VIII) 58 km

Note I have added a few moons as I went along, but lots are missing.

After that, I haven't put any and all bodies in (believed) order, but I can give you the largest asteroids in the Asteroid Belt, with 'diameter' in km. (BUT most will probably not be spherical, so take diameter as you wish)::

Ceres 934
Pallas 526
Vesta 510
Hygiea 408 0rb430
Davida 326
Interania 316
Europa 302
Juno 268
Sylvia 260
Euomnia 256
Euphrosyne 256
Psyche 254
Cybele 240
Bambergo 230
Patentia 226
Doris 222
Camilla 222
Herculina 222
Eugenia 214


Here are some Dwarf Planets: 'diam' km.

Eris 2326
Pluto 2306
Haumea 1960
Makemake 1440
Quaoar 1070
Sedna 995
Ceres 952
Orcus 917
Ixion 650



Cat :)
 
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Nov 10, 2020
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"Yep there is actually a pretty big gap between these objects and the next largest dwarf planet or moon"
I am not sure what you mean by that. My impression is that they all clump up together, very often with changes in order. On that basis I will continue the list, but please don't tell me there are errors. The order keeps changing with new/improved/whatever measurements:

After,
Haumea 1960 km
Titania 1577 km
Rhea (Saturn V) 1527 km
Oberon (Uranus IV) 1523 km
Iapetus (Saturn VIII) 1468 km
Makemake (136472) 1440 km
2007 OR10 (225088)
Charon (Pluto I)
Umbriel (Uranus II) 1169 km
Ariel (Uranus I) 1158 km
Dione, (Saturn V) 1123 km it continues
Quaoar (50000) 1070 km
Tethys (Saturn III) 1062 km
Sedna (90377) 995 km
Ceres (I) 934 km / 952 km / 914 km take your pick
2002 MS4 (307261)
Orcus (90482) 917 km
Galacia (120347)
2002 AW197
Varda (174567)
2013 FY27 (532037)
2003 AZ84 (208996)
Dysnomia (Eris I)
Ixion 650 km
Enceladus (Saturn VI) 504 km
Miranda (Uranus IV) 471 km
Porteus (Neptune III ) 420 km
Mimas (Saturn VII) 396 km
Hyperion (Saturn VIII) 360 km
Nereid (Neptune II) 340 km
Amalthea (Jupiter V) 250 km
Phoebe (Saturn IX) 213 km
Janus (Saturn X) 203 k
Larissa (Neptune IV) 194 km
Galatea (Neptune VI) 176 km
Himalia (Jupiter VI) 170 km
Puik (Uranus XV) 154 km
Sycorax (Uranus XVII) 150 km
Despina (Neptune V) 148 km
Portia (Uranus XII) 135 km
Thebe (Jupiter VII) 116 km
Elara (Jupiter VII) 80 km
Thalassa (Neptune IV) 80 km
Naiad (Neptune VIII) 58 km

Note I have added a few moons as I went along, but lots are missing.

After that, I haven't put any and all bodies in (believed) order, but I can give you the largest asteroids in the Asteroid Belt, with 'diameter' in km. (BUT most will probably not be spherical, so take diameter as you wish)::

Ceres 934
Pallas 526
Vesta 510
Hygiea 408 0rb430
Davida 326
Interania 316
Europa 302
Juno 268
Sylvia 260
Euomnia 256
Euphrosyne 256
Psyche 254
Cybele 240
Bambergo 230
Patentia 226
Doris 222
Camilla 222
Herculina 222
Eugenia 214


Here are some Dwarf Planets: 'diam' km.

Eris 2326
Pluto 2306
Haumea 1960
Makemake 1440
Quaoar 1070
Sedna 995
Ceres 952
Orcus 917
Ixion 650



Cat :)
Yeah the use of radius or diameter as a gauge of size is tricky since the bodies get considerably less spherical which actually was one of my criterion for the cut off at Pluto and Eris Haumea is for instance much shorter on one axis than the other with its bulge having a diameter comparable to Pluto and Eris but its polar axis being much much smaller. It does seem that it was once in hydrostatic equilibrium with a very high angular velocity but whether it is still in equilibrium or is just frozen into that shape is quite difficult to gauge.

There has been recent work which suggests that icy objects with diameters between 400 and 1000 km might be intermediary objects with uneven differentiation which makes assessing dwarf planethood problematic.

On this subject there are also weird bodies like Hygiea which appear to be differentiated despite lacking sufficient mass to self differentiate via accretion/collapse.

Also Saturn is a bit weird as its smaller moons still contain examples which appear to still be in hydrostatic equilibrium which is highly improbable if they are as old as the solar system though given that the system appears to be much younger than other planetary systems "only" around a billion years old rather than the 4 and a half billion years age of the solar system as a whole (Closer to 4.7 Gya for the Sun but on these kinds of timescale a few hundred million years is negligible)
 
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Jun 1, 2020
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I think that if we are getting sights of some of these, esp. TNOs, it should be difficult to miss P9 or P10 unless its albedo is virtually zero.

Cat :)
The inverse 4th law makes it more difficult than one would expect. A P9 at 10x Pluto’s distance makes it 10,000 times dimmer (assuming identical to Pluto).

A P10 — I’ve shelved this idea — at 50,O00 AU would be ~ 1 trillion times dimmer.

Even a Jupiter at ~ 10,000 AU becomes invisible to the HST, IIRC.

iPhone
 
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May 14, 2021
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At one time, I had a college level astronomy textbook from 1948 that had Pluto’s diameter as 6600 miles (no, American textbooks didn’t use metric yet) considering the technology of the day (Polomar 5 m scope wasn’t a thing yet). So, it was rightfully a planet at the time. Then, when Charon was discovered, and found that Pluto was actually tiny, it was demoted. When my granddaughter was in elementary school, they had a science night, and I was there for astronomy and my scope, not long after Pluto wa demoted. They asked why the demotion. I explained the reasons given by IAU, and said it was either that or we learn bunches of new planet names. They said ‘OK, let’s make Pluto not a planet’.
 
Jun 1, 2020
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At one time, I had a college level astronomy textbook from 1948 that had Pluto’s diameter as 6600 miles (no, American textbooks didn’t use metric yet) considering the technology of the day (Polomar 5 m scope wasn’t a thing yet). So, it was rightfully a planet at the time. Then, when Charon was discovered, and found that Pluto was actually tiny, it was demoted.
Charon (“Karen”) likely wasn’t a reason for demotion.

When my granddaughter was in elementary school, they had a science night, and I was there for astronomy and my scope, not long after Pluto wa demoted. They asked why the demotion. I explained the reasons given by IAU, and said it was either that or we learn bunches of new planet names. They said ‘OK, let’s make Pluto not a planet’.
That is the main reason. :). But it is a planet, kinda,... a dwarf planet.
 
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Catastrophe

The devil is in the detail
Is there a 9th planet? If so, then how big, dense, and massive is it? What is its orbit around the sun and gravitational effect on the Solar System?

There are loads of rocks out there - probably some big ones. If (or when) they find one, some are bound to shout "That's Planet 9"

Cat :)
 
Mar 13, 2021
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Planet X. or Planet 9 ?? Ancient Astronomers etc...

Before Pluto was "demoted" to the status of a "minor Planet" which was controversial, ( & apparently there is a movement to again get Pluto recognized as the 9th planet ), people used the term "Planet X" to speculate about the presence of an as yet undetected 10th planet beyond Pluto. This roman numeral "X" for 10, also had an intriguing "X-Factor" mystery ring to it, and some folks still prefer to use the term Planet X. Although modern study of the effects of gravity in our distant solar system using advanced mathematics is reviving this question, the ancient Sumerians & Babylonians apparently speculated about a similar distant long orbit planet they called Nibiru ! ....J.Gieni
 

Catastrophe

The devil is in the detail
What does anyone think is important if someone finds another 'Pluto'? The atmosphere now is totally different from 1930. These days, we know that there are zillions of rocks, a few large, billions smaller, out there in the Oort Cloud and the Kuiper Belt. And don't forget TNOs. Some are comets, because they have those chemical compositions. Some rocks. like Oumuamua may came from further still. It has been found recently that there are more rogue planets and even rogue stars, than formerly believed. What if Oumuamua had come into orbit? Would that have been called a planet, or another dwarf planet?

Cat :)
 

Catastrophe

The devil is in the detail
Helio, I was making a point. That is if anything, round, oblate or stick-like enters orbit, some will yell "Planet X". I just suggested a possibility impinging on the 'Planet Whatever' syndrome.

Cat :)
 
Jul 27, 2021
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If Earth dominates its orbit with a large Moon, so does Pluto have an even larger moon proportionately (Charon), and 4 other minor moons.
"The vote took place at the August 2006 IAU meeting in Prague, which included 424 voting members (out of a total membership of 9,000). The majority vote was for Pluto to be redesignated as a dwarf planet, along with a number of other "trans-Neptunian objects" discovered in the few years before the vote"

However, Pluto crosses the orbit of Neptune and has more akin with Eris and other dwarf planets. So Pluto was the 9th planet; now there are 8 plus a number of dwarf planets, TNOs and other similar sized, and smaller, objects.

Cat :)
The IAU rules and conventions. Could be voted, reconsidered? For instance simulations might add 'virtual' planets with a certain list of evidences.
 
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Catastrophe

The devil is in the detail
Helio Post #75

Sorry, I missed this. I think it was from the IAU link, which included inter alia the following extracts:

Quote
The naming process for Eris stalled after the announcement of its discovery in 2005, because its size was comparable to that of Pluto. The IAU sought to resolve the naming of Eris by seeking a taxonomical definition to distinguish planets from minor planets.
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"If Neptune had cleared its zone, Pluto wouldn't be there", he has said, despite the fact that the IAU category is nearly identical to his own category of überplanets.[6]
Quote
However, Stern himself co-developed one of the measurable discriminants: Stern and Levison's Λ. In that context he stated, "we define an überplanet as a planetary body in orbit about a star that is dynamically important enough to have cleared its neighboring planetesimals ..." and a few paragraphs later, "From a dynamical standpoint, our solar system clearly contains 8 überplanets"—including Earth, Mars, Jupiter, and Neptune.[3] Although he proposed this to define dynamical subcategories of planets, he still rejects it for defining what a planet is, advocating the use of intrinsic attributes[7] over dynamical relationships.
Quote

It was on the subject of planet definition and clearing orbit.

Cat :)
 
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Jul 27, 2021
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Astronomers detected new large sub-Neptune alien world (TOI-2406 ).
the planet is expected to be a good candidate for transmission spectroscopy in the warm Neptune regime with NASA's James Webb Space Telescope (JWST).

 
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Sep 5, 2021
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Ah, I'm not sure about that then. There is a theory that it's just a black hole because of the gravitational pull. I don't believe it is a planet.
There's no chance to be a black hole. If it was, earth and rest of the whole system could be somewhere in the deep space. There is a theory that says, even if a small black hole pass nearby the solar system, all the planets will move pretty far from its current position and it'll be catastrophic. So, I guess there's no black hole. Actually, I think astronomers hide the truth about this 9th planet.
 

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