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A ninth planet?


Spaceception

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5 hours ago, RuBisCO said:

Yeah sure, again make it work and I'll believe you. 

Make the public be willing to send up multiple *thermonuclear bombs* into orbit... and make other countries like China and Russia be cool and not at all paranoid about it, and make the US congress (or change names of countries and governing bodiesas desired, selecting from among nuclear armed states with ICBM capabilities) willing to pay for it...

FYI, the public complains a lot about just sending up RTGs.

Nukes work, we've shown that many many times.

Shaped charges work. IIIRC, they've even already built shaped charge nukes for bunker busting capabilities.

Shock absorbers work

Ablative materials that can withstand the energies and heating involved have alreayd been tested.

 

Its all there, what isn't there is the will to spend the money, and take the risks of trying to loft a "doomsday package" to orbit.

One such rocket would basically be a nuclear arsenal that would be the envy of many states. A launch vehicle failure would be a disaster particularly if the warheads fall in an area where some "non-coopertive" nations are able to recover them.

And a launch from the surface under orion drive power... whelp, there goes all the progress done by the test ban treaties... oh, and then there's the EMPs generated high in the atmosphere as it circularizes

 

Edited by KerikBalm
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35 minutes ago, K^2 said:

It'd be a total speculation, and pushing the plausible range from the data so far, but for a KSP mod, it'd be fun to build an ice Super-Earth version of Nine. 10M is right there at the edge of Super-Earth definition, but in principle, this could allow for a hard surface made up primarily of Methane ice, with lakes of liquid Hydrogen and a Hydrogen-Helium atmosphere. The atmospheric pressure would be within a few bar limit, and surface gravity would be within tolerable for a landing. I'd also throw in a few moons. Could make for some really interesting challenges, and it'd be different.

Edit: So here are some numbers to go along with that. Assuming Nine has a rocky core, but still covered by a lot of ice, I would guess that it'd be rather dense for an ice giant, and rather fluffy for a rocky world. So I went with 3g/cm³. That might be a little high, but we're stretching things here to make it fun for the game. That puts radius at a little under 17,000km. Almost 3x the Earth's. The neat thing about that is that the surface gravity, ends up being mere 13.8m/s². About 40% higher than Earth's! You'd be able to survive on that world, provided sufficient heat insulation. The orbital velocity would be rather high, at about 15km/s, which is about twice that for Earth, but it's nothing insane. Finally, the atmosphere. Depending on typical temperature, it could be anywhere from 1 to 10 bar. On the plus side, scale height should be comparatively small, making it a little easier to escape.

Scaling that to KSP, I'd do basically the same thing they did with Kerbin. Take radius at 1/10th and keep the surface gravity. That would put radius of KSP Nine at 1,700km and surface gravity at 1.4g. That puts orbital velocity in KSP at 4,834 m/s. Then I would set surface pressure at 4 atm and scale height at 4km. That will make ascent from Nine about as challenging as ascent from Eve, especially since there won't be any significant mountains on the surface to help you along.

Doubt it would look like that. Since it would be so close to Super Earth/Ice giant, it would likely have an extremely think atmosphere, to the point where gases get supercritical (like on Venus), but even then, they would likely be things closer to 0*C water in temperature, due to internal heating. It might be possible to land, but good freaking luck getting out of the gravity well.

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7 hours ago, ChrisSpace said:

So basically it's one step 'behind' Titan? So the Methane on P9 is like water ice on Titan and rock on Earth, and the Hydrogen is like Methane/Water?

I don't see any way there could be a patch of liquid Methane/Water/Ammonia on such a cold planet.

I'm with fredinno on this one. Remember that since the planet is so much colder, it can hold onto much more Hydrogen and Helium despite being smaller than the gas/ice giants.

Only problem is that if it was ejected from the early solar system (which is the leading theory right now) it would not be able to gather on much more stuff before it left the dust/gas belts forming the planets and Kuiper belt anyways. That's also likely why it's smaller than Uranus and Neptune.

7 hours ago, K^2 said:

It's also significantly smaller than either of these ice giants, with far weaker greenhouse effect, due to lower illumination. Expecting it to be only 20K colder than Uranus or Neptune is unfounded. RuBisCO's estimate of 40K upper bound is much more plausible.

Lower mass also means significantly less Hydrogen, and methane freezes at 90K. So unlike the ice giants, which are basically huge methane slushies, Planet Nine actually has a pretty good chance to have solid methane "land". All depends on just how much Hydrogen it has.

If it was all frozen methane, it would look nothing like we could imagine. The immense pressure would make for some really weird and exotic ices. Assuming you can send a probe down to that layer, something which would be a serious engineering challenge.

7 hours ago, Rdivine said:

Of course it must be solid! How else are the Annunakis gonna stand on the planet Nibiru itself!? :wink:

 

But in all seriousness, i'm guessing that it's a gas giant similar to jupiter. I read previously that models suggested that a gas giant may have formed between Saturn and Jupiter, and then flung out into deep space. Additionally, the planet may not be radiating much energy is because it might not have received enough energy from the Sun in the first place.

No GAS giant, it was an ICE giant that was proposed by that 'extra planet formed' theory. And internal heating happens regardless of external energy sources.

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9 hours ago, K^2 said:

It is. But if it's the Fifth Giant, we are likely looking on the smaller end of that estimate. So it'd still be the smallest of the Ice Giants.

Uranus is 15 times heavier than earth so I guess this will be like Uranus or Neptune but smaller,

if its in the smaller end it might not keep hydrogen and helium but have an fairly dense atmosphere like titan and ice surface, not an ice giant like Uranus and Neptune but more like an super earth or water planet. 
 

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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.

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Why is everyone talking like it is a fact? There is nothing yet that 100% proves its existence, let alone what it is made of. Don't get me wrong, it would be amazing if there was a new planet, but we're not at the stage to be absolutely certain that it's there...

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Maybe it'll be an ice giant that froze and all its gases fell and gave it solid ground. Maybe it'd have lakes of hydrogen. Since WISE didn't detect it, it must be below a certain temperature. Does anyone know what the limit is for WISE to detect something like this? It'd be quite significant in what kind of planet it is because we could then calculate its temperature based on parameters we already theorized.

Edited by Findthepin1
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A planet of the mass proposed is going to have a hot core from when it formed, which will be several thousand Kelvins. When the middle is that hot, whether the outside is at 20 K or 200 K doesn't make a lot of difference to how long it takes to cool.

Whether it has a solid surface then depends on how the gradients in pressure and temperature with depth compare to the melting point of whatever it is made of. There are I think two plausible structures. Either way there will be an outer atmosphere of helium and probably hydrogen. If that atmosphere is thin the pressure and temperature at its base will be such that methane is solid and there will be a solid surface. If the atmosphere is thick enough though it will grade into methane gas or supercritical fluid, with no solid surface.

Considering how much hydrogen and helium Neptune and Uranus have, at 15 Earth masses overall, I think for a planet of ten Earth masses the latter structure is *far* more likely.

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23 hours ago, relin said:

So we essentially got lucky in finding Pluto? That's crazy.

Yeah, it is.  Right place, right time, a certain amount of luck.

A similar accident led to the discovery of Ceres, the largest asteroid in the Main Belt.  A mathematical "law" was derived that showed a simple pattern in the relative distances of the planets from the Sun (called the Titus-Bode Law).  It worked pretty well, except that it predicted a planet between Mars and Jupiter.  So a whole lot of astronomers were hired to look for something at that distance -- and Ceres was there.

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2 hours ago, 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.

We would likely orbit, or send a penetrator probe into it until it's crushed. Realistically, it's so big, it probably won't have a terrestrial 'surface'. It might resemble it somewhat, but an ice giant is still an ice giant- meaning it has no real surface. If it is closer to a gas dwarf super-earth, then landing on it will be more impractical than Venus due to higher pressure- meaning we probably won't worry about it until after the next 1-2 centuries.

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1 hour ago, chadgaskerman said:

The problem I have with planet nine is that A. How come why didn't notice it from the changed orbits of the trans-neptunian objects and B. the orbital changes don't look right to me

 

 

 

Do tell me that's not just me

Thaye did do A. That's how they found it. Also, a large object clears its orbit (at least partially) so it would influence Oort Cloud objects and TNOs.

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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. 

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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?

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Just now, Just Jim said:

With all due respect, I'm 53, and most of my life I've heard theories that Pluto was "just a snowball"... turned out to be anything but...  :wink:

By snowball I mean that it's made of solid ices. Pluto is still made of lighter materials, but solidified.

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10 hours ago, fredinno said:

Doubt it would look like that. Since it would be so close to Super Earth/Ice giant, it would likely have an extremely think atmosphere, to the point where gases get supercritical (like on Venus), but even then, they would likely be things closer to 0*C water in temperature, due to internal heating. It might be possible to land, but good freaking luck getting out of the gravity well.

Atmospheric pressure is limited by vapor pressure of constituents. Methane is going to be frozen out, and Helium won't be sufficiently abundant. That leaves a Hydrogen-dominated atmosphere. And in plausible temperature ranges, that gives us upper limits on pressure in 1-10 bar, perhaps as high as 100 bar if there is a strong greenhouse effect, but that's a stretch already. Anything else will condense and rain down as Liquid Hydrogen.

These are very low pressures. Conditions much closer to what we see on rocky worlds than gas giants. I'll grant you, that this is very unusual for a Gas/Ice Giant, or even a large Super-Earth, but only because our study is focused on much warmer worlds. We tend to see the smaller worlds have a solid surface, and large worlds have layers. But the boundary depends on size and temperature of the world. A good example, once again, is Venus. It's an Earth-sized world, but due to its temperature, it already starts exhibiting some of the features we expect of a large Super-Earth. Likewise, Nine should be an ice giant. And had it remained in the outer system, it would certainly be one of these layered planets with no well-defined surface. But with temperatures as lows they should be on that world, I expect an environment that at the first glance looks very terrestrial. A well-defined surface, either icy with lakes of Hydrogen, or a global Hydrogen ocean, and above it, an atmosphere of a few bar with clouds of Hydrogen mist. All on a world with a surface gravity 30%-50% higher than that on Earth. If it weren't for temperatures, I'd say it'd make a good world for a colony.

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43 minutes ago, Veeltch said:

So basically those smaller bodies all have similar perihelions and are more or less in the same plane, which can't be a coincidence, right?

There is no such thing as "can't be a coincidence," in physics, unfortunately, but when odds are less than a tenth of a percent, the safe bet is on there being some sort of a mechanism involved. And of known mechanisms that could account for it, a planetary body is the most plausible. Very far from certainty, but between that and Nice Model suggesting there was another giant in the early Solar System, it seems more likely that Planet Nine is there than that it isn't. Certainly enough of a reason to put an effort in finding it visually.

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