Planet 10?

[Helio]

A study shows major terrestrial events every ~27.5 million years. [Here]

Hypothetically, a planet with an aphelion of 91 thousand [not million] AU (just inside outer Oort) and a perihelion of, perhaps, just inside or outside 1 AU (Earth’s distance) could explain this cycle. It’s current distance would beyond all optical scopes.

Terrestrial explanations are mentioned as well.

 

[Catastrophe]

Helio, I am well aware of the "ellipse with the Sun at one focus" bit, but I had always considered planetary orbits to be close to circular. I cannot find anything to stipulate this, but I assumed it followed from the planet formation mechanism.

Orbital eccentricity - Wikipedia

en.wikipedia.org

From: Orbital eccentricity it confirms my thought, in that most (major) planets' orbits are close to circular. Eccentricities are quoted. Considering this reference, I would have called your Planet 10 a comet, but I can easily be missing something. How would you explain a fairly massive object with such a high eccentricity?

Cat

P.S. Has not this same cycle been attributed to Earth's movement up and down through the galactic plane, as the galaxy rotates?

 

[Wolfshadw]

P.S. Has not this same cycle been attributed to Earth's movement up and down through the galactic plane, as the galaxy rotates?

I agree with this as the source of these "regular" terrestrial events.

-Wolf sends

 

[Helio]

Helio, I am well aware of the "ellipse with the Sun at one focus" bit, but I had always considered planetary orbits to be close to circular. I cannot find anything to stipulate this, but I assumed it followed from the planet formation mechanism.

Cometary orbits are often eccentric. Hyutake, for instance, is 0.9998. (0 is circular; 1 is parabolic)

From: Orbital eccentricity it confirms my thought, in that most (major) planets' orbits are close to circular. Eccentricities are quoted. Considering this reference, I would have called your Planet 10 a comet, but I can easily be missing something.

It may fit a dwarf planet definition since the farther an object is from the Sun, the more massive it must be to clear an orbit.

How would you explain a fairly massive object with such a high eccentricity?

The same way Planet 9 is explained - it’s inferred from other observations. But, like P9, confidence is weak. More evidence is needed, especially for this hypo dwarf.

 

[Catastrophe]

Helio, I posted:
"Helio, I am well aware of the "ellipse with the Sun at one focus" bit, but I had always considered planetary orbits to be close to circular. I cannot find anything to stipulate this, but I assumed it followed from the planet formation mechanism."
to which you replied:
"Cometary orbits are often eccentric. Hyutake, for instance, is 0.9998. (0 is circular; 1 is parabolic)".
I do not see the connection. I know comets' orbits can be very eccentric, in fact that was my very point. I am suggesting that if planets were formed from the planetary disc, how would some become that eccentric? IOW why not call P9 and P10 comets and have done with it. Here, I was working on P9 and P10 being what you called them - planets - and not dwarf planets.
The rest is self explanatory.

In brief, why do you need P9 and/or P10 at all?

Cat

 

[Helio]

I was too quick, apparently, to jump to a cometary definition.

Regardless of our label, is there a way we can falsify it? I’m reluctant to accept internal -events inside Earth - reasoning given the lengthy period and regularity.

 

[Catastrophe]

"A study shows major terrestrial events every ~27.5 million years. [Here]"

Sorry, I'm with the galaxy on this one!

Cat

 

[Helio]

"A study shows major terrestrial events every ~27.5 million years. [Here]"

Sorry, I'm with the galaxy on this one!

Cat

What do you mean by “galaxy”?

 

[Catastrophe]

As above. Over that period we are orbiting the galaxy, passing up and down through the galactic plane. Density varies during the journey so that means consequences do not follow an exact cycle. That's from memory, so I will go check.

Don't understand P 9/10 at all. How massive are you suggesting? And do I understand perihelion approx 1 AU and aphelion 99 million AU? Really???

Cat

The variation in the Galaxy as Earth travelled through accounts for the variation in effects:

""These new findings of coinciding, sudden mass extinctions on land and in the oceans, and of the common 26- to 27-million-year cycle, lend credence to the idea of periodic global catastrophic events as the triggers for the extinctions," said Michael Rampino, a professor in New York University's Department of Biology and the study's lead author. "In fact, three of the mass annihilations of species on land and in the sea are already known to have occurred at the same times as the three largest impacts of the last 250 million years, each capable of causing a global disaster and resulting mass extinctions."

"The team analyzed the ages of 89 well-dated major geological events of the last 260 million years. These events include marine and land extinctions, major volcanic outpourings of lava called flood-basalt eruptions, events when oceans were depleted of oxygen, sea-level fluctuations, and changes or reorganization in the Earth's tectonic plates."

 

[Catastrophe]

Here we are:

"The Sun and planets cycle through the crowded mid-plane of the Milky Way Galaxy about every 30 million years. During those times, comet showers are possible, leading to large impacts on the Earth. The impacts can create conditions that would stress and potentially kill off land and marine life, including widespread dark and cold, wildfires, acid rain, and ozone depletion"

Dark matter's shadowy effect on Earth | Astronomy.com
https://astronomy.com › magazine › 2019/07 › dark-m...

31 Jul 2019 — Earth's periodic passage through the galaxy's dark matter disk could ... that mass-extinction events followed a 26 million-year cycle.

Mass extinctions of land-dwelling animals occur in 27-million ...
https://www.dailymail.co.uk › article-9042601 › Mass-e...

11 Dec 2020 — ... of land-dwelling animals follow a 27-million-year cycle and could be ... The researchers suggest they could be dictated by Earth's orbit ...

https://imgur.com/a/HoZzMy5

View: https://imgur.com/a/HoZzMy5


Cat

 

[Helio]

As above. Over that period we are orbiting the galaxy, passing up and down through the galactic plane. Density varies during the journey so that means consequences do not follow an exact cycle. That's from memory, so I will go check.

I would bet our bobbing up and down through the plane would encounter no more new matter than without bobbing. A kid jumping straight up and down on a train encounters the same track as the kid sitting.

Don't understand P 9/10 at all. How massive are you suggesting?

Well, too massive would affect Earth’s orbit. Too small would likely affect the object, thus disrupting the “heartbeat”. But I’m weak on celestial mechanics.

And do I understand perihelion approx 1 AU and aphelion 99 million AU?

Yikes! A 1500 lyr. orbit is an iPhone glitch. I meant 91,000AU perihelion, thus yielding the ~27.5 million year period. [P^2 = a^3]

[update: Oops, “a” is only half that of aphelion for e close to 1. Thus, this object would travel beyond the Oort, too far to be possible. This may be enough falsification!]

What inside Earth could cause such a reliable, periodic activity?

iPhone

 

[Catastrophe]

"What inside Earth could cause such a reliable, periodic activity?"

Nothing I know of.

"I would bet our bobbing up and down through the plane would encounter no more new matter than without bobbing. A kid jumping straight up and down on a train encounters the same track as the kid sitting."

Very poor analogy [sorry], but, if you must, "banging his head on the ceiling" and "falling badly back on the floor" - not to mention stuff hanging around in the air.

I am by no means gullible and, if you check it out, it makes a lot of sense to me. Concentrations of objects in the plane are responsible for more impacts et cetera, and variation in object density give the variation in severity.

Still, I know, if one does not like a theory to begin with, one may never give it the chance of consideration. Maybe I feel that way about P9 / P10?

Cat

 

[Helio]

Very poor analogy [sorry], but, if you must, "banging his head on the ceiling" and "falling badly back on the floor" - not to mention stuff hanging around in the air.

I regret that I agree.

But the point implies that something would have to be in the plane where the Sun passes and it this something that would also be traveling along at the same orbital speed as the Sun (tracks).

Worse, perhaps, is that the bobbing period is ~ 67 million years (33.5 myrs. per pass). Yet, that’s not far off, so I wonder if an adjustment could be justified, as needed.

I am by no means gullible and, if you check it out, it makes a lot of sense to me. Concentrations of objects in the plane are responsible for more impacts et cetera, and variation in object density give the variation in severity.

That’s plausible. Any serious reference? I would assume astronomers have studied this section of the galactic disk we pass through.

Still, I know, if one does not like a theory to begin with, one may never give it the chance of consideration. Maybe I feel that way about P9 / P10?

Since I have fun shooting from the hip, I have to be quick to let my weak ideas go.

The name of the game in science is always objectivity. Subjective feelings can help, but they can hurt progress as well.

 

[Helio]

Speaking of shooting from the hip...

If every 4th pass was responsible for Earth’s disruption, then an aphelion of 72k AU would be needed for our celestial culprit.

 

[Catastrophe]

Helio, don't forget you have to allow some relative motion. If the Galaxy moved like a cast iron wheel, there would be no relative motion.
How do you calculate 72k AU aphelion on Galaxy rotation model?

Cat