A question, regarding a gas giant, for Worldbulding project?

[NeptuneRise]

Hi there! I'm new here , and I was looking for some information, if people here can provide me with that?

I'm working on a Worldbuilding project, where I'm creating a fictional universe, but I want the worlds that I and others would create, to be based on real scientific facts, with real astronomical data, and to be subject to our natural laws of physics, just like other worlds in our real universe.

So, what I was thinking is, could there be a planet, let's say, a huge gas giant, but with a solid core made of rock and water? Liquid water?

What conditions would such a planet demand? Under what circumstances could this happen?

And what role does the size of the planet play in the formation of a liquid water, in correlation with the distance from it's star?

If it really is possible, this is the second part of my question:

This planet that I'm talking about, is in the 4th orbit around it's star, making it the last one in the orbital order. How distant should this planet be in order for this liquid water to be maintained, and not freeze over?

Can the necessary heat for this (which already comes from the star), be achieved with the "heat aid" of 3 (or more) hot molten lava moons revolving in very close proximity to the gas giant?

Any answers that remotely satisfy the information I need for these questions would be very appreciated. I also hope that this might also turn into an interesting discussion among those who are heavily into astronomy and astrophysics. Thank you .

PS: If I get my answers to this question, I may post some more questions regarding the nature of the planet. It's an exotic world with more than one "strange" phenomena under it's name.

PSS: Also, whoever feels like she/he can contribute to this Worldbuilding project in any way possible, or wants to be a part of it, please let me know. I take all kinds of people, with all kids of ideas and all kinds of advices/help they offer, well ... 99.99% of the time hehe . As long as the project is still what the name suggests and does not turn into something else.

[Boikat]

I'm not a physicist, and I don't play one on TV, but just at a guess, i do not think that liquid water could exist at the core under the pressure extremes of a Jupiter sized gas giant. I'm not even sure if water molecules could even survive. Maybe they can. It would also depend on the size of your core. If you mean a "Jupiter sized" super-duper "earth", where the atmosphere is just a thin layer, then it may be possible for liquid water at the surface, but that would depend on how water behaves under the influence of the extreme gravity. not to mention the compression of the rest of the atmosphere under such gravity. But using a strictly Jupiter sized and structure, I do not know if it is possible, and I doubt anyone would be able to visit unless they do so in a diamond hulled submarine, and that's just to get through the atmosphere. Then there would be the temperatures to deal with.

Here's the Wiki on Jupiter:

http://en.wikipedia.org/wiki/Jupiter

The part about the structure should help.

How far away from the parent star the planet would have to be in order to maintain any sort of liquid water at the surface would also depend on the size and temperature of the star. In our solar system, that distance, known as the "Goldilocks Zone" extends from (IIRC) just outside the orbit of Venus to just inside the distance to the asteroid belt. If Mars had been Earth sized, it would likely have oceans, possibly liquid, if the CO2 concentration was high enough for a good greenhouse effect. As it is, even with the thin atmosphere currently present, day-time temps at the equator can reach the low 70's (I think).

Receiving heat from molten moons would be problematical, since explaining molten moons around a non-molten planet would imply the moons are molten for some reason, since the smaller bodies would cool off before the planet would, so they would have to be molten due to something like a large impact with a huge asteroid or another moon. Getting three of them to be molten would almost be imply something artificial was occurring, especially if the planet was reasonably intact.

[NeptuneRise]

First off, thank you very much for replying Boikat, you are the first, and the bravest one!

I'm not a physicist, and I don't play one on TV, but just at a guess, i do not think that liquid water could exist at the core under the pressure extremes of a Jupiter sized gas giant. I'm not even sure if water molecules could even survive. Maybe they can.

It doesn't have to be a gas giant per say. I need a planet that's 3 times the size of Jupiter, but the size being due to large number of layers of atmosphere. The solid part would only be equal to a third of the size of the entire planet, the rest being the layers of atmosphere. I need a deep atmosphere because one of the species on this planet lives there, and the rest of the species live on the solid part.

The reason I said gas giant was because I don't know any other planet type that can offer similar characteristics. If there is, let me know.

It would also depend on the size of your core. If you mean a "Jupiter sized" super-duper "earth", where the atmosphere is just a thin layer, then it may be possible for liquid water at the surface, but that would depend on how water behaves under the influence of the extreme gravity.

Only together with the atmosphere they make a large planet, but the solid part would be smaller. No extreme gravity to make the water solid, but extreme nonetheless, yes.

not to mention the compression of the rest of the atmosphere under such gravity. But using a strictly Jupiter sized and structure, I do not know if it is possible, and I doubt anyone would be able to visit unless they do so in a diamond hulled submarine, and that's just to get through the atmosphere. Then there would be the temperatures to deal with.

Here's the Wiki on Jupiter:

http://en.wikipedia.org/wiki/Jupiter

The part about the structure should help.

No, the atmosphere is actually the opposite to thin lol. And the gravity is not that extreme too lol.

How far away from the parent star the planet would have to be in order to maintain any sort of liquid water at the surface would also depend on the size and temperature of the star. In our solar system, that distance, known as the "Goldilocks Zone" extends from (IIRC) just outside the orbit of Venus to just inside the distance to the asteroid belt. If Mars had been Earth sized, it would likely have oceans, possibly liquid, if the CO2 concentration was high enough for a good greenhouse effect. As it is, even with the thin atmosphere currently present, day-time temps at the equator can reach the low 70's (I think).

The planet is 2.3 A.U. away from it's parent star who is F5V main sequence type star. It's in the habitable zone. It's perfect for life to emerge.

Receiving heat from molten moons would be problematical, since explaining molten moons around a non-molten planet would imply the moons are molten for some reason, since the smaller bodies would cool off before the planet would, so they would have to be molten due to something like a large impact with a huge asteroid or another moon. Getting three of them to be molten would almost be imply something artificial was occurring, especially if the planet was reasonably intact.

They are in very close proximity to the planet, and they spin very rapidly around it. I believe the fast spin would make some pretty great disturbances inside the moons in question and cause extreme volcanic activity due to, tidal heating, I believe was the term? But I can erase those moons if they don't fit realistically with this planet. They were just a thought, acting as a help mechanism to add to the necessary heat needed to maintain water in liquid form on the planet.

Thank you for your input, you got me thinking

[Boikat]

Interesting idea, but *physics-wise*, based upon Jupiter, I do not see any way around the pressure problem. You may want to look into some form of "weird physics" or some peculiarity of the system. An example that jumps to mind is Larry Niven's "Integral Trees", which has habitable gas cloud circling the parent star called "The Smoke Ring". It's been a few decades...er...*years*..ahem... since I read it, so I don't remember how it was "explained".

I did a Google Search, and here's the poop on "The Integral Trees":

http://en.wikipedia.org/wiki/The_Integral_Trees

According to the article, the existence of the smoke ring is due to the parent planet "Gold" being close to the Roche Limit of the star. The Roche Limit is where the tidal forces from the parent body are so much stronger on the near side than on the far side of the satellite moon or planet, that it is torn apart. You could use the three moons you mentioned as being very large, as in very, very large, and the tidal influence strong enough to pull the atmosphere outward. I think that would cause strong "atmospheric tides" that would be pretty destructive, however, unless they were in a near stationary orbit, relative to the surface of the planet.

I seem to recall that Kieth Laumer also had a story of a "twin planet" that was so close they shared their atmosphere, both were pear shaped with the "pointy ends" pointed at each other, and the atmosphere was dense between the two points that the inhabitants were able to fly biplanes between the two planets. (The plot of that story was the inhabitants had invaded each others planets so many times that neither one of the two alien species knew which planet was their original home world.) But fond as i am of Laumer's works, he was not too much into the physics of his stories. It depends on how nit-picky your target audience is.

But that's some ideas. Maybe someone else will pipe in..

GUYS!! A little help here! Guys!!!!?????

[The Master]

I have never studied astronomy so I lack the technical expertise to answer your questions with any authority. In other words, your google is as good as mine!

That said, it is my understanding that a gas giant is, by definition, gas with some possibility that it has some heavy elements at the core (we don't really know). Thus, as Boikat said liquid water is not something I would imagine would be found on one. Most SF of which I am aware uses the moons that orbit gas giants as their potential settings, not the planet itself. Even in Star Wars notice that they went to the moon of Endor, not to the planet it orbits.

Another possiblity would be to create an entirely new type of lifeform that doesn't depend upon the same elements of life that we do. In other words, create a being that either doesn't need water to live, or that can gleen water vapor from the gases of its atmosphere rather than rely on liquid water.

As for an alternative planet type is much larger than earth physically without having crushing gravity I believe that mass is what is important for gravity, not necessarily physical size (although the two often correlate). The earth has heavy metals like iron at its core. If it was elements with lower mass the planet's gravity would be lower. Do not overlook the possiblity that life on a heavier gravity planet could simply be adapted to it with stronger bone structures, larger muscles, etc. I see no reason you can't make a larger atomosphere simply by having it be thinner.

I think molton moons are neither realistic scientifically nor plausible for a story. In other to have been captured by the planet's gravity they would have to be far less dense. As boikat said I think they would have cooled off far before the planet did. At best you might have some volcano activity due to a still active core, but its not going to be enough to significantly affect the planet it orbits.

I hope some of that is helpful. Again I must bow to my ignorance of the hard science that might apply here. I'm strictly from the "I made it up" school of SFF

[Asp Zelazny]

Admittedly, this is somewhat late to the original question posting, but you might gain some insight into the problems of creating a world of this nature by reading any of the later editions of Hal Clement's book Mission of Gravity, first published in 1954. In this story, he postulates a *solid* giant world, with variable gravity dependent upon the distance from the equator, and provides a very interesting story of a human explorer stranded on the planet and his interaction with an intelligent native life form. It's a good book, and worthy of a look, even though it is not a gas giant planet like you hope to create. In the later editions, though, there is an appended section that goes into quite a bit of detail (presented in a fashion that is perfectly understandable to any reasonably intelligent reader, and not requiring an advanced degree in planetary science) on the physics of creating a 'realistic' world at the extremes of size, rotation, gravitation, and orbit. His expostion of the planet Mesklin may be the kind of thing you are looking for.

Good luck with your world building!

[NeptuneRise]

According to the article, the existence of the smoke ring is due to the parent planet "Gold" being close to the Roche Limit of the star. The Roche Limit is where the tidal forces from the parent body are so much stronger on the near side than on the far side of the satellite moon or planet, that it is torn apart. You could use the three moons you mentioned as being very large, as in very, very large, and the tidal influence strong enough to pull the atmosphere outward. I think that would cause strong "atmospheric tides" that would be pretty destructive, however, unless they were in a near stationary orbit, relative to the surface of the planet.

As for an alternative planet type is much larger than earth physically without having crushing gravity I believe that mass is what is important for gravity, not necessarily physical size (although the two often correlate). The earth has heavy metals like iron at its core. If it was elements with lower mass the planet's gravity would be lower. Do not overlook the possiblity that life on a heavier gravity planet could simply be adapted to it with stronger bone structures, larger muscles, etc. I see no reason you can't make a larger atomosphere simply by having it be thinner.

Admittedly, this is somewhat late to the original question posting, but you might gain some insight into the problems of creating a world of this nature by reading any of the later editions of Hal Clement's book Mission of Gravity, first published in 1954. In this story, he postulates a *solid* giant world, with variable gravity dependent upon the distance from the equator, and provides a very interesting story of a human explorer stranded on the planet and his interaction with an intelligent native life form.

I just want to thank everyone for their answers . They were a lot of help. I apologize for the late reply, but I have been very busy for an entire year and didn't have the time to come and thank you properly.

I have used the weird gas giant in my fictional universe, but less far-fetched, and lifeless. But I have turned the idea of the life forms that should have been hosted by the gas giant down to them existing on a Super-earth type of planet, few times the size of Earth, but lower than expected gravity, as the planet is less massive less than expected), and significantly lesser density (I've read this can allow for more giant lifeforms to exist on a planet that's larger than Earth), and it would also explain the large atmosphere with many layers.

My more simpler life forms have been evolved into a very rich biosphere, totally different than what i was going for. I decided to put only one moon on it, and it is hinted in the narrative that it could be of an artificial extraterrestrial origin.

Anyway, thanks again for you help, much appreciated .

[Asp Zelazny]

You're welcome, and thanks for letting us know that there is still someone out there writing good ol' science fiction (please don't tell me that you've populated your Super-earth with dwarves and fairies ...).

Keep us informed about how you're doing.

[NeptuneRise]

You're welcome, and thanks for letting us know that there is still someone out there writing good ol' science fiction (please don't tell me that you've populated your Super-earth with dwarves and fairies ...).

Keep us informed about how you're doing.

Hahahaha, no no ...

I do write fantasy fiction too sometimes, but even there, when creating a fantasy universe, as any universe, it has its own nature and laws. So whatever I would be creating, would still have to obey those laws, just like a real universe. I do like well-thought out concepts and lots, and I do mean lots of details .

As far as science fiction, and the super-earth planet, its populated by life-forms that are neither plant nor animal, but sort of both, and are nitrogen|phosphorus-based as opposed to us humans, carbon-based.

Here's one of the designs if you are interested in the looks of it , there's some background story under the picture.

Yeah, I'll keep in touch