Evidence of an unknown planet in our solar system?

GWGeorge007
GWGeorge007
Joined: 8 Jan 18
Posts: 2,850
Credit: 4,721,468,524
RAC: 3,292,451
Topic 231018

Scientists say they have found evidence of an unknown planet in our solar system.  New findings represent the ‘strongest statistical evidence yet’ that Planet 9 exists, researcher says.

https://www.independent.co.uk/space/planet-9-nine-solar-system-b2530985.html

A paper describing the work, ‘Generation of Low-Inclination, Neptune-Crossing TNOs by Planet Nine’

https://arxiv.org/pdf/2404.11594.pdf

George

Proud member of the Old Farts Association

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,550
Credit: 288,918,881
RAC: 87,785

Yes, they use computation of

Yes, they use computation of possibilities :

'... we carry out comprehensive N−body simulations that self-consistently model gravitational perturbations from all giant planets, the Galactic tide, as well as passing stars, stemming from initial conditions that account for the primordial giant planet migration and sun’s early evolution within a star cluster'

Seems all encompassing. Anyway this yields predictions* ie. go and have a look and see if anything is there!

'... herein offer a set of readily-falsifiable predictions, with near-term prospects for resolution'

Proper science then. They suggest a measurement of the orbital distribution of the class of objects considered. 

Notably the initial timestep was 100 days and an entire simulation time was 4 billion years! If they mentioned where they did the calculations, what hardware was used etc, I can't see that written.

Now if there is a Planet Nine found it will be an amazing thing indeed. For instance it's surface will probably be strewn with all those lost ballpoint pens ... the red ink ones especially.

* That overall methodology of predict-look-see has a long historical pedigree eg. Neptune was discovered (by Johann Gottfried Galle) via looking in the sky where calculations (by Urbain Le Verrier & John Couch Adams independently) said it should be. Post facto it had been seen by several others including Galileo. There's a similar story for Pluto. Gosh all those guys were smart.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

GWGeorge007
GWGeorge007
Joined: 8 Jan 18
Posts: 2,850
Credit: 4,721,468,524
RAC: 3,292,451

Mike Hewson wrote: Yes, they

Mike Hewson wrote:

Yes, they use computation of possibilities .....

..... Gosh all those guys were smart.

Cheers, Mike.

Yes, Mike, you are absolutely correct!!  I for one couldn't even DREAM of these planets!

George

Proud member of the Old Farts Association

mikey
mikey
Joined: 22 Jan 05
Posts: 12,059
Credit: 1,834,324,605
RAC: 24,074

Mike Hewson wrote: Yes, they

Mike Hewson wrote:

Yes, they use computation of possibilities :

'... we carry out comprehensive N−body simulations that self-consistently model gravitational perturbations from all giant planets, the Galactic tide, as well as passing stars, stemming from initial conditions that account for the primordial giant planet migration and sun’s early evolution within a star cluster'

S

Cheers, Mike.

Are the "N−body simulations" they use similar, or even the same, as the MilkyWay Boinc Project is using? I guess I'm wondering if the work being done by MilkyWay is or could be used to find "Planet Nine"?

mikey

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,550
Credit: 288,918,881
RAC: 87,785

Short answer : Yes they are

Short answer : Yes they are similar, but no you can't use their results. Each N-body simulation is different in the number of bodies and the so-called initial conditions plus some other stuff.

Long Answer : N-body simulation is a general idea rather than a specific technique. The idea is that the gravitational force law is expressed in terms of two bodies (let's assume they are using Newton's Law of Gravity or some expression derived from that). Now if you only have two bodies in your simulation the mathematics is the simplest, the orbits are all 'conic sections' : circles, ellipses, parabolas, hyperbolas etc, depending on the total energy in the system. Now if you put in even a single extra body (ie. N>2) you can no longer solve the equations in 'closed form', put another way there is no neat mathematical function that describes the situation. But one can solve for the evolution of the system - where are all the bodies and how are they moving - by simulation or mathematical approximation. This is a time step method and each body is assumed to move according to some average influence over a short enough interval. To mitigate the errors of approximation the time steps may vary and the whole situation is subject to checks so that conservation laws (energy, momentum, angular momentum) are upheld. But this explanation is too simple (& dated) to describe what they actually do. There are a lot of references in the paper to earlier studies that have dealt with the methodology. It seems quite a refined, and arcane, field of study so that if Planet Nine is verified as a true finding then the methods are also validated.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

mikey
mikey
Joined: 22 Jan 05
Posts: 12,059
Credit: 1,834,324,605
RAC: 24,074

Mike Hewson wrote: Short

Mike Hewson wrote:

Short answer : Yes they are similar, but no you can't use their results. Each N-body simulation is different in the number of bodies and the so-called initial conditions plus some other stuff.

Long Answer : N-body simulation is a general idea rather than a specific technique. The idea is that the gravitational force law is expressed in terms of two bodies (let's assume they are using Newton's Law of Gravity or some expression derived from that). Now if you only have two bodies in your simulation the mathematics is the simplest, the orbits are all 'conic sections' : circles, ellipses, parabolas, hyperbolas etc, depending on the total energy in the system. Now if you put in even a single extra body (ie. N>2) you can no longer solve the equations in 'closed form', put another way there is no neat mathematical function that describes the situation. But one can solve for the evolution of the system - where are all the bodies and how are they moving - by simulation or mathematical approximation. This is a time step method and each body is assumed to move according to some average influence over a short enough interval. To mitigate the errors of approximation the time steps may vary and the whole situation is subject to checks so that conservation laws (energy, momentum, angular momentum) are upheld. But this explanation is too simple (& dated) to describe what they actually do. There are a lot of references in the paper to earlier studies that have dealt with the methodology. It seems quite a refined, and arcane, field of study so that if Planet Nine is verified as a true finding then the methods are also validated.

Cheers, Mike. 

That helps alot thanks!!

Scrooge McDuck
Scrooge McDuck
Joined: 2 May 07
Posts: 872
Credit: 16,314,111
RAC: 5,136

If there is significant

If there is significant evidence (or probabilities) for a Planet Nine, scientists should quickly find an appropriate Roman name for it, while there is still plenty of time to think and consider.

mikey
mikey
Joined: 22 Jan 05
Posts: 12,059
Credit: 1,834,324,605
RAC: 24,074

Scrooge McDuck wrote: If

Scrooge McDuck wrote:

If there is significant evidence (or probabilities) for a Planet Nine, scientists should quickly find an appropriate Roman name for it, while there is still plenty of time to think and consider.

I would think there would be alot of support to just bring back Pluto as it was dropped because the then Pluto wasn't a planet after all.

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,550
Credit: 288,918,881
RAC: 87,785

My vote, not that anyone is

My vote, not that anyone is counting on me, is for Planet Claire. ;-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Scrooge McDuck
Scrooge McDuck
Joined: 2 May 07
Posts: 872
Credit: 16,314,111
RAC: 5,136

mikey schrieb: I would think

mikey wrote:

I would think there would be alot of support to just bring back Pluto as it was dropped because the then Pluto wasn't a planet after all.

This will lead to an outcry from these people: www.plutoisaplanet.org/

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.