six-year search of the outer solar system turns up 461 new objects (but no Planet 9)

[notFritzArgelander]

https://phys.org/news/2021-09-six-year- ... lanet.html

PS No you're not going all deja vu all over again, the editors failed to cut a repeated paragraph.....

[GCoyote]

Good, thought I was losing it there for a second.

[notFritzArgelander]

Good, thought I was losing it there for a second.

With that many new not-planet-9 objects an analysis of the orbits might be interesting. Is the alleged correlation of TNO orbits real?

[helicon]

I saw that. Kind of curious.

[notFritzArgelander]

I saw that. Kind of curious.

It's interesting, but I'd rate it "as expected".

IF TNOs have correlated orbits and I suspect that the "apparent correlation" Beelzebrown relies on is a mirage created by selection effects

AND IF the correlation was caused by a planet like body

THEN we know from https://phys.org/news/2021-02-evidence- ... ering.html from the thread https://theskysearchers.com/viewtopic.p ... t=Planet+9 that the odds are about 3 to 2 against it still being in the Solar System.

To reduce the odds even further, we already know that a planetary mass of the right size was ejected from the solar system during the great migration of planetary orbits to the current ones. I think it's a fool's errand to look but now that Mike Brown & Co. have let it out of the box it needs to be checked thoroughly.

[KingNothing13]

To reduce the odds even further, we already know that a planetary mass of the right size was ejected from the solar system during the great migration of planetary orbits to the current ones.

How do we know that? Not questioning the science, etc. behind it - I trust the scientist and the people that have been studying and working on it their entire lives - just wondering how we know this happened? What is the science behind it?

[notFritzArgelander]

To reduce the odds even further, we already know that a planetary mass of the right size was ejected from the solar system during the great migration of planetary orbits to the current ones.

How do we know that? Not questioning the science, etc. behind it - I trust the scientist and the people that have been studying and working on it their entire lives - just wondering how we know this happened? What is the science behind it?

Here we go, then, no worries. Articles from

Scientific American

https://www.scientificamerican.com/arti ... st-planet/

Astronomy Now

https://astronomynow.com/2015/11/03/jup ... years-ago/

An interesting admission from Brown that his Planet 9 left the Solar System in the Wikipedia article (see near the bottom)

https://en.wikipedia.org/wiki/Five-planet_Nice_model

And lastly, but certainly not least, the science behind it all from arXiv:

https://arxiv.org/abs/1509.05397

Models of the dynamical evolution of the early solar system following the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant mass, which gets ejected by a gas giant during the early solar system's proposed instability phase. We investigate the likelihood of an ice giant ejection event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus respectively. We show that planetary encounters that are sufficient to eject an ice giant, often provide excessive perturbations to the orbits of Callisto and Iapetus making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite orbit with the current orbit of Callisto following an ice giant ejection by Jupiter of ~ 42% and conclude that such a large likelihood supports the hypothesis of a fifth giant planet's existence. A similar calculation for Iapetus reveals that it is much more difficult for Saturn to have ejected an ice giant and reconcile a Kronian satellite orbit with that of Iapetus (likelihood ~ 1%), although uncertainties regarding the formation of Iapetus, on its unusual orbit, complicates the interpretation of this result.

It's all just Newton. The four planet Nice model is here:

https://en.wikipedia.org/wiki/Nice_model

Essentially Uranus and Neptune could not have formed in their present locations. The density of material in the proto solar system disk would be too low. This can be resolved by the Solar System being originally more compact with resonances and planetesimal driven orbital instabilities forcing transport to the remoter orbits we see now. The five planet Nice model with an ejected planet looks more like what we see now.

[KingNothing13]

Awesome, thanks nFA - I will add these sites to my reading list - which is growing.

[notFritzArgelander]

Awesome, thanks nFA - I will add these sites to my reading list - which is growing.

Glad to help.