A ninth planet?

[Azivegu]

On 23-1-2016 at 7:00 PM, Camacha said:

If this thing turns out to be real, and it has not cleared its orbit, the whole Pluto/planet/orbit discussion is going to be held all over again. Obviously you cannot have a definition with a huge planet not being an actual planet, so it will be interesting to see what contrived definition will surface this time

I believe the definition of a cleared orbit is that the mass of all objects intersecting the orbit of the discussed body has to be significantly less then the discussed body. For example, the Moon is by far the largest object intersecting the earths path, but is only about 1.2% that of earth.

Charon on the other hand is more than 12% the mass of Pluto, and we havent even discussed other objects intersecting Pluto's path. That is why it failed to be recognized as a planet. Its the exact same story for Ceres. So if Pluto gets made a planet, then there is no reason not to do the same with Ceres, and then Pluto will never be number 9.

[Rakaydos]

6 hours ago, llanthas said:

Sorry, but didn't we already rule out a Planet X decades ago?  "The orbits wouldn't work" was the explanation, I believe....  Now the 'orbits wouldn't work' without it?  Make up your minds!

Different orbits. Decades ago we didnt even know about the objects we're now using to infer PlanetX's existance.

[Camacha]

1 hour ago, Azivegu said:

r hand is more than 12% the mass of Pluto, and we havent even discussed other objects intersecting Pluto's path. That is why it failed to be recognized as a planet. Its the exact same story for Ceres. So if Pluto gets made a planet, then there is no reason not to do the same with Ceres, and then Pluto will never be number 9.

Wait, are you saying that double planets are impossible by definition? In that case the definition is off, way off. I think a sister body does not actually counts towards the clearing its orbit requirement, since 1) its orbit ensures the two will never* meet and 2) both can be thought of as a single system or entity. The question is whether the Pluto constellation has cleared its orbit.

The issue some people have with Pluto being a planet is, formally, the other objects not in the Pluto system itself. Pluto has not cleared that path sufficiently and that is why it was demoted. Though one could argue that was not really the problem either. The orbital clearing definition has been concocted to deal with the many newly discovered TNOs and Pluto most likely being one of that. That is made it necessary to come up with a planetary definition that excludes Pluto.

It is pretty obvious the current definition is contrived and designed to fit our solar system. As soon as that solar system turns out to be slightly different, or other solar systems are mapped with any degree of accuracy, it likely quickly falls apart. That is not surprising, since we know so little about it. Adjustments are inevitable when we fill in the blanks.

*Any time soon

 

6 hours ago, llanthas said:

Sorry, but didn't we already rule out a Planet X decades ago?  "The orbits wouldn't work" was the explanation, I believe....  Now the 'orbits wouldn't work' without it?  Make up your minds!

That is a little bit like saying mankind could never fly, because we strapped wings to a man and it failed to lift off. A unsubstantiated idea that does not cooperate with the mechanics as we know it was disproven, but that does not mean that any and all ideas regarding an additional planet are false.

 

Edited January 25, 2016 by Camacha

[magnemoe]

1 hour ago, Azivegu said:

I believe the definition of a cleared orbit is that the mass of all objects intersecting the orbit of the discussed body has to be significantly less then the discussed body. For example, the Moon is by far the largest object intersecting the earths path, but is only about 1.2% that of earth.

Charon on the other hand is more than 12% the mass of Pluto, and we havent even discussed other objects intersecting Pluto's path. That is why it failed to be recognized as a planet. Its the exact same story for Ceres. So if Pluto gets made a planet, then there is no reason not to do the same with Ceres, and then Pluto will never be number 9.

Don't think moons count here but junk not in orbit.
An planet larger than earth would anyway be an planet.

Remeber that they assumed Pluto was far larger then they made it an planet, Mars sized at least. 
Then they start finding lots of tans Neptune objects so they had to either include all with an lower size requirement as in larger than Ceres, 
Much of the same story for Ceres it was found and recognized as an planet, then they found lots of other asteroids and it lost the title. 

[Mitchz95]

Brown apparently believes we can get a probe there in twenty years by doing a powered slingshot close to the sun.

https://www.newscientist.com/article/2074961-how-planet-nine-may-have-been-exiled-to-solar-systems-edge/

[Nothalogh]

4 hours ago, Mitchz95 said:

Brown apparently believes we can get a probe there in twenty years by doing a powered slingshot close to the sun.

https://www.newscientist.com/article/2074961-how-planet-nine-may-have-been-exiled-to-solar-systems-edge/

Holy smokes, he's going for the Oberth-Kuiper Maneuver

[K^2]

That... That could actually work. Twenty years is still a bit optimistic. I'm only getting a 70km/s escape from a Jupiter dive and a 10km/s burn. Diving from higher up would work, but that would still add to trip time. But decades instead of centuries? I'll take that.

[fredinno]

On January 21, 2016 at 0:44 PM, K^2 said:

What does that have to do with discoverers' names? These are Shakespearean characters. And being fictional characters, it's not much different from naming planets after Gods.

Well, someone's an optimist...  With periapsis of 200AU, and it might be significantly higher, we could get a probe to periapsis in a few decades, yes. But this orbit has a period of 10-20ky. So it's very unlikely to be anywhere near periapsis right now. Given the kind of rockets we can realistically build, we might be able to make a probe that gets to it in a few centuries.

Assuming we can make or would make a probe lasting for a few centuries. Either way, it's more that Shakesperean names sound really weird in the view of the other planetary names. 

[fredinno]

On January 22, 2016 at 8:30 PM, Jeanjvs said:

OMG! It's a scam! NASA knows that something of the magnitude of New Horizons won't happen again soon, so they have been hiding this planet all these years!

 

WAKE UP SHEEPLE!!

 

Brought to you by the YouTube comment section of [any video about space exploration]

It would be easier if NASA just said they would develop Kinetic Bombardment Weaponry.

[Mitchz95]

I think any mission to this planet should be an orbiter, simply because it's so hard to get there. Obviously it would have to be a pretty heavy-duty craft; I don't even want to think about the delta-v requirements. Some kind of ion engine, but with an on-board nuclear reactor to generate power (because obviously solar won't cut it that far from the sun).

Would it be possible to do multiple flybys of this planet to bring the perihelion up, then do a final insertion burn after a few solar orbits?

[fredinno]

On January 22, 2016 at 8:34 PM, Starwaster said:

OH NOES! IT IS THE END OF DAYS! PLANET NIBIRU COME TO KILL US ALL!!!

I can't read this. Please translate.

 

On January 22, 2016 at 8:59 PM, Nothalogh said:

 

And what is so hard to believe?

The design is not limited by physical or technical constraints, only political

And economical.

On January 22, 2016 at 9:28 PM, K^2 said:

It's a Nice giant, which makes it an ice giant. Unless it's a capture, but then we're just guessing.

What's a "Nice giant?" Is it a giant planet that is nice to the other planets and tries not to sling comets into the rest of the Solar system?

On January 22, 2016 at 9:31 PM, AccidentsHappen said:

Wow, I didn't even think of that. Would you classify that as "semi-terrestrial" or "super-dense-comet-10-times-the-size-of-Earth"? I was thinking in the direction of a Gas Giant devoid of internal heat, and so cold that parts of its atmosphere have condensed, frozen and fallen, compacting at the planets core and creating a "surface". I'm really not sure, but I love the theories.

Like Mann's planet. That is what we should call this planet.

On January 22, 2016 at 9:57 PM, legoclone09 said:

What if it had internal heating but it collapsed into a huge ocean of liquid water? That would be AWESOME!

Too cold for that.

On January 22, 2016 at 10:30 PM, legoclone09 said:

Why not call it a liqanet? Like a liquid-planet combo.

AKA an ocean planet?

3 minutes ago, Mitchz95 said:

I think any mission to this planet should be an orbiter, simply because it's so hard to get there. Obviously it would have to be a pretty heavy-duty craft; I don't even want to think about the delta-v requirements. Some kind of ion engine, but with an on-board nuclear reactor to generate power (because obviously solar won't cut it that far from the sun).

Would it be possible to do multiple flybys of this planet to bring the perihelion up, then do a final insertion burn after a few solar orbits?

No, because one you flyby it, you're pretty much done. It's moons probably won't affect you too much, so insertion will have to be fully propulsive. The planet orbits so slowly it might as well be stationary for all practical puposes.

[Mitchz95]

Right. I forgot that you have to be at escape velocity to reach it in the near term.

Still, a propulsive orbital insertion would be nice. But again, it would have to be a pretty hefty probe.

Edited January 26, 2016 by Mitchz95

[Findthepin1]

Maybe its atmosphere condensed and it ended up with a surface of liquid/supercritical Hydrogen and methane ice underneath that. Geology would be weird. The thing would still have internal heat so you could end up with a core of rock and whatnot, then a regular ice giant mantle, then a layer of liquid then solid methane and similar compounds, on top of that a mainly hydrogen ocean covering the whole globe. Then atmosphere. A more complex situation analogous to, say, Titan. A core of rock, molten?, then definitely solid rock, then ice-six, then water, then normal ice, then liquid methane. See, weird. 

Edited January 26, 2016 by Findthepin1
Titan is weird it has 3 different liquids in or on it

[fredinno]

On January 22, 2016 at 7:39 AM, Scotius said:

Question: if this world is so cold even hydrogen is close to freezing, how can we explore it? Our probes, landers and bodies would radiate so much energy, everything around them would be vaporised. If we cooled down every part coming in contact with environment, that part would become brittle - to the point of shattering under its own weight.

You would need really good insulation.

On January 22, 2016 at 0:14 PM, magnemoe said:

Uranus is 15 times the mass of earth, if this is 10 its an small ice giant, thick atmosphere, most of the mass is ices, iron and rock core.
If smaller and only x times earth it become super earth / ice planet, much like large jovian moons but far larger, that is this limit?
This is more interesting than an small Uranus.
Does it has an atmosphere or will everything freeze. ?
How about subsurface lakes? unlike moons pressure rise fast as you go down and ice behave strange under insane pressures. 

Probably too high of a pressure for that.

On January 22, 2016 at 0:17 PM, KerikBalm said:

which still makes me wonder if there was some weird orbital resonance that actually would result in the titus bode law being an reasonable approximation... a weird resonance that falls apart with greater distance from the sun/longer orbital periods (stuff happens too slow and something else dominates instead)... such that it fall apart past uranus...

Anyway, whatever predictive power it may have had (predicting *something* between mars and jupiter) is long gone.

I'm not convinced by anything in the images, but I don't have the expertise to really get into the math.

The images showing the orbits of known objects, and there positions (all close to perapsis), do however convince me that there must be a lot more objects out there, after all these things spend far more time out near apoapsis than perapsis.

If this planet 9 theory? hypothesis? is correct, then there wouldn't be as many as previously predicted, because it would have cleared/ejected a large portion of them, no?

That's not how resonances work. Resonances are when objects stabilize each other's orbits by gravitationally interacting with each of her at specific ratios of their orbits. For example, 1:2, 3:7. I doubt all the planets would be locked in a resonance (+Ceres, -Neptune.)

32 minutes ago, Findthepin1 said:

Maybe its atmosphere condensed and it ended up with a surface of liquid/supercritical Hydrogen and methane ice underneath that. Geology would be weird. The thing would still have internal heat so you could end up with a core of rock and whatnot, then a regular ice giant mantle, then a layer of liquid then solid methane and similar compounds, on top of that a mainly hydrogen ocean covering the whole globe. Then atmosphere. A more complex situation analogous to, say, Titan. A core of rock, molten?, then definitely solid rock, then ice-six, then water, then normal ice, then liquid methane. See, weird. 

It would likely be molten in the center due to its size-but y the time it gets to the surface, it's too cold, so only hydrogen is in a liquid format, resulting in a hydrogen cycle, and infinite rocket fuel ready to use .

[K^2]

1 hour ago, fredinno said:

What's a "Nice giant?" Is it a giant planet that is nice to the other planets and tries not to sling comets into the rest of the Solar system?

Nice Model. As in city in France. Solar System formation comes out all sorts of wonky with just four giants. Adding a fifth giant, which gets knocked out of the early Solar System makes the simulation evolve pretty much into a replica of Solar System. So in that regard, the model is, actually, quite nice. Given that Nice Model and latest research point to an ice giant of roughly the same size, it's not a stretch to assume that they are one and the same. At any rate, that's way more likely than a rogue capture.

[fredinno]

On January 22, 2016 at 3:20 PM, RuBisCO said:

I think it is best to consider what solid methane is like even at extreme cryogenic temperatures: it would have the mechanical strength of lard (lard at our temperature of course). A planets surface made of lard is not like anything we know of.

Also consider Uranus's cloud deck temperature is 120-55 k and it's black body temperature at its average distance from the sun (19.2 AU) is 90 K, Neptune is averaging 73 K, and its blackbody temperature at 30 AU is 72 K. So there is very little internal heating. This theorized planet is getting far less sunlight, enough equivalent to blackbody temperatures of 11-27 K. Using Neptune and Uranus as very poor rules of thumb as they don't have such wide temperature regimes, it is perfectly possible this planet has an average temperature below 20 K, and that hydrogen liquifies naturally. It could have a Helium atmosphere and hydrogen rain, seas of hydrogen-methane sludge. 

Only problem is methane solidifies much before hydrogen.

On January 22, 2016 at 3:52 PM, Bill Phil said:

It might have some really weird colors.

No, likely blue, if it is like an ice giant.

On January 23, 2016 at 5:25 PM, Bill Phil said:

Planet 9 From Outer Space

What is this from?

 

1 minute ago, K^2 said:

Nice Model. As in city in France. Solar System formation comes out all sorts of wonky with just four giants. Adding a fifth giant, which gets knocked out of the early Solar System makes the simulation evolve pretty much into a replica of Solar System. So in that regard, the model is, actually, quite nice. Given that Nice Model and latest research point to an ice giant of roughly the same size, it's not a stretch to assume that they are one and the same. At any rate, that's way more likely than a rogue capture.

I know about the Nice model, just not a "Nice Giant".

[fredinno]

On January 23, 2016 at 9:43 PM, RuBisCO said:

So I ran the numbers my self, we would need a spacecraft averaging 47 km/s top reach this theorized planet in 20 years, if it was at perihelion, which it probably is not, if it is at its 1200 AU aphelion, we would need a spacecraft averaging 285 km/s! A Dual-Stage 4-Grid ion engine propelled spacecraft with a specific impulse of 19300 would need to be 23-79% propellant by mass to get there in 20 years.  

You would need an enormous nuclear reactor and radiators to power the energy-hungry DS4Gs.

On January 23, 2016 at 10:00 AM, Camacha said:

If this thing turns out to be real, and it has not cleared its orbit, the whole Pluto/planet/orbit discussion is going to be held all over again. Obviously you cannot have a definition with a huge planet not being an actual planet, so it will be interesting to see what contrived definition will surface this time

It will likely be based off the approx minimum mass of a object that has cleared its orbit.

On January 23, 2016 at 1:05 PM, Nothalogh said:

There are two approaches to mitigate ground effect fallout, ocean surface launch, or a graphite coated launchpad.

As for chemical boosted Orion, that's like using a horse to get your car up to 20mph before engaging the engine.

 

And, again, you're trying to compare weapons testing to the use of pulse propulsion devices, it's disingenuous at best

That will still be horrible for the Earth, and be incredibly unpopular. Even LEO might be bad, as it is within the magnetosphere.

On January 24, 2016 at 6:09 AM, Rdivine said:

I've wondered, what if we hit that 0.007% of it not existing at all? There's always a chance  

Then it becomes an intersellar probe, and uses its remaining life and propellant studying the interstellar space.

On January 24, 2016 at 1:07 PM, Pawelk198604 said:

So you say it's Rouge Planet???

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

 

Cool

 

No, this planet is supposed to orbit the Sun.

 

[KerikBalm]

1 hour ago, fredinno said:

That's not how resonances work. Resonances are when objects stabilize each other's orbits by gravitationally interacting with each of her at specific ratios of their orbits. For example, 1:2, 3:7. I doubt all the planets would be locked in a resonance (+Ceres, -Neptune.)

Well, yea, that is sort of what I was wondering. The titus bode law would describe specific orbital distances, which would then have specific orbital periods, which would have specific ratios. They may not come out to a nice integer ratio though (maybe not even as good as the 355/113 approximate ratio for Pi)

Somehow, the titus bode law became a somewhat accurate crude approximation for the semi major axis of relatively stable concentrations of mass (planets+asteroids belt) within the "inner solar system" (a term hard to define, especially if this planet 9 is there expanding our definition).

If we consider the Nice model, it too is ultimately an equation/algorithm... just much much much more complicated. Basically I wonder if its pure chance that the law worked for so many planets, or if there are very complex orbital mechanics going on that would tend to repeatedly produce this set of ratios for the inner solar system

[KerikBalm]

2 hours ago, fredinno said:

No, because one you flyby it, you're pretty much done. It's moons probably won't affect you too much, so insertion will have to be fully propulsive. The planet orbits so slowly it might as well be stationary for all practical puposes.

I think its additionally worth pointing out... that at the distances we're talking about... multiple flybys for gravity assist to raise PE would take longer than recorded human history... longer than it took human to get from the earliest human structures (these, as far as we know: https://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe#Chronological_context which predate pottery, writing and agriculture) to the Moon landing (or the internet, or atomic power, or whatever moden achievement you wish to use as a land mark... because when we're talking over 10,000 years, who cares about several decades...

[magnemoe]

7 hours ago, Nothalogh said:

Holy smokes, he's going for the Oberth-Kuiper Maneuver

That looks like an project for an probe who would fly low over one of suns poles, using Jupiter to bend your orbit and Venus to get you to Jupiter. 

[fredinno]

9 minutes ago, magnemoe said:

That looks like an project for an probe who would fly low over one of suns poles, using Jupiter to bend your orbit and Venus to get you to Jupiter. 

Like Ulyesses?

[magnemoe]

46 minutes ago, fredinno said:

Like Ulyesses?

yes, that was it, I thought it also passed Venus but mix up probes.  

[Findthepin1]

6 hours ago, magnemoe said:

yes, that was it, I thought it also passed Venus but mix up probes.  

Almost nobody remembers Ulysses anymore. 

[fredinno]

42 minutes ago, Findthepin1 said:

Almost nobody remembers Ulysses anymore. 

It any case, it died in 2006. WE should get something new out there, but I don't really think that's scientifically high priority.

[RuBisCO]

21 hours ago, fredinno said:

It any case, it died in 2006. WE should get something new out there, but I don't really think that's scientifically high priority.

INTO THE SUN!!!