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Ninth planet discovered?

There is now (tentative) evidence for a ninth planet in the solar system! If it exists, this planet would be in a highly elliptical orbit and would be fifteen times further from the sun than Pluto at its closest approach. Most excitingly though, it appears to be massive - with a radius four times that of earth!

This is all very hypothetical right (I don't think a paper has been published yet) but if this is true, it would be an extremely exciting discovery with major ramifications on our models for solar system formation since we cannot currently explain how such a massive object could exist so far away from the sun.

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Why wasn't it discovered when the previous planets were?
Original post by GeologyMaths
Why wasn't it discovered when the previous planets were?


Because back then they weren't looking for a planet far away enough that we can plant Donald Trump on it and now they are.
Reply 3
Avatar for Alexion
Alexion
17
Original post by GeologyMaths
Why wasn't it discovered when the previous planets were?


Hmm, let me see...

The planets we all know oh so well were discovered over the last few hundred years by observation. We could see them all, as they're close enough to be bright enough to be observable from our position in the solar system.

This new 'planet' has not been observed, and won't be visible from Earth (or from its orbitals) due to the fact that it is at minimum 15x further away than Pluto (as quoted above). Evidence for its existence is only based on the effects it has on rocks in the outer reaches of the solar system.

Basically, we can see the other planets, we can't see this one.
Original post by GeologyMaths
Why wasn't it discovered when the previous planets were?


The previous planets weren't discovered at the same time
Reply 5
Avatar for Nephthys
Nephthys
1
It's Nibiru
Original post by GeologyMaths
Why wasn't it discovered when the previous planets were?


It's very far away from the sun so reflects practically no light to the earth and it is so far away that its gravitational influence on most objects we can easily observe is very small. The reason why we think it exists is because of the unusual behaviour of some Kuiper belt objects that are by themselves difficult to observe. It's a bit unintuitive that we can "easily" observe exoplanets that are light years away from us yet we can't observe a planet that's only a few hundred AUs away but exoplanet discovery methods work with giant planets that orbit very close to the parent star (which results in a measurable change of velocity of something very massive and easily observable) or in rare cases which massive planets transit across a star (which obviously isn't applicable in this case).

It does actually highlight the danger posed by "dark" objects in the solar system because there are potentially hazardous objects that exist in the solar system that are practically unobservable.
When do we draw a line with what is actually in our solar system exactly?
We've been making all these discoveries but missed something right under our nose apparently
(edited 8 years ago)
mercury venus earth mars jupiter saturn nepturne uranus pluto

that should be the 10th planet jebus
Original post by cbreef
When do we draw a line with what is actually in our solar system exactly?


This. If its 15 times further then pluto then surely it would be closer to another star then ours.
Original post by cbreef
When do we draw a line with what is actually in our solar system exactly?
We've been making all these discoveries but missed something right under our nose apparently


I'd say if it's orbiting our Sun, then it's in our solar system. There will be a certain distance from the Sun where it's gravity will have no tangible effect, so we could call it there.
Original post by Zargabaath
I'd say if it's orbiting our Sun, then it's in our solar system. There will be a certain distance from the Sun where it's gravity will have no tangible effect, so we could call it there.


But that must stretch for lightyears surely. For our sun to have ZERO effect on something must be a very, very large distance indeed
(edited 8 years ago)
I just want them to reinstate Pluto :frown: it was my favourite planet!
Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn
Reply 14
Avatar for RMNDK
RMNDK
3
Original post by cbreef
When do we draw a line with what is actually in our solar system exactly?
We've been making all these discoveries but missed something right under our nose apparently



It's generally agreed that the edge of the solar system is 50,000 to 100,000 AU which are the lower and upper limits of the the radius of the Oort Cloud.

Basically this is just a huge megastructure consisting of rocks, dust and other space junk that surrounds the sun in a spherical 'cloud'. The reason why this is the limit is cos this is considered the 'end' of the gravitational pull of the Sun. Like, beyond this point, the Sun's gravitational attraction is negligible.

This possible planet is within this range.
Original post by RMNDK
It's generally agreed that the edge of the solar system is 50,000 to 100,000 AU which are the lower and upper limits of the the radius of the Oort Cloud.

Basically this is just a huge megastructure consisting of rocks, dust and other space junk that surrounds the sun in a spherical 'cloud'. The reason why this is the limit is cos this is considered the 'end' of the gravitational pull of the Sun. Like, beyond this point, the Sun's gravitational attraction is negligible.

This possible planet is within this range.


50,000 AU is how many lightyears/metres/kilometres???
Whichever you prefer
Original post by Platopus
I just want them to reinstate Pluto :frown: it was my favourite planet!


Your name should have been 'Plutopus' instead.
Original post by Mentally
This. If its 15 times further then pluto then surely it would be closer to another star then ours.


No. You grossly underestimated how far our sun and solar system is away from the next star.

This predicted new planet is 0.001 light years away from the sun. The next nearest star is 4.24 light years away from our sun. This is over 4000 times the distance away than that of the sun to this predicted new planet.

That was worked out from a 2 minute google search, just sayin'.
What if that planet has alien life and is only making itself known to us now, because the inhabitants want to make contact with us! Like they have been monitoring us for hundreds of years and we are finally technologically advanced enough for them to make contact with us. What if on another planet, in another galaxy the life forms make sci-fi films where we are the aliens and we kill people? What if the aliens that live on this hypothetical planet have the secret to eternal living or the cure to all known diseases or the solution to global warming, a renewable fuel source...
Just makes you think...
Original post by cbreef
But that must stretch for lightyears surely. For our sun to have ZERO effect on something must be a very, very large distance indeed


Well if you're going by zero effect of gravity, the entire universe would be our solar system as the gravity of any mass effects the whole universe, just not in any tangible way. I mean the point where gravity is so exponentially weak, it can't make any object fall into an orbit.

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