Preview: Sirius Planetary System In Construction.

[d.m.falk]

While reading over this thread, a few things came to my mind:

1: Neutron stars are encrusted in lead.

2: Ne\utron stars occasionally have surface quakes/explosions that crack or expel the crust.

3: This world could be the recipient of such lead.

While it is true that formation would mean the heaviest materials sink to the center, it is also true that all worlds are constantly bombarded by the debris not only of their systems' formations, but from the formation or destruction (or expulsion) of other worlds.

And don't forget Sirius B could be the source of some matter not found in Sirius A.

d.m.f.

[ajtribick]

Neutron stars have a lead crust? The sources I've come across on this matter suggest that the crust is iron, which becomes steadily more neutron-rich as you go down.

And DON'T try to suggest that there could be a neutron star in orbit around one of the components of Sirius - an object that massive would have been detected a long time ago!

As for sourcing materials from a second star - don't count on it! While you can get contamination (I think barium dwarfs form in this way), I strongly doubt you'd be able to dump enough lead on a planet that it reacts with all the stuff lead will react with, and leave some elemental lead over to form oceans. It took a LONG time to start building up significant oxygen levels in the Earth's atmosphere, even though the source was on the planet - for a distant source, particularly one as short lived as a red giant, no chance.

[d.m.falk]

I never suggested that there is any such neutron star in orbit in the Sirius system.

I did however, state that Sirius B could be the source for exotics on any world orbiting Sirius A, being that B is a white dwarf, a collapsed stellar core smaller than the Earth. (A is also listed as a "metal rich" star.)

As for neutron stars, while they are very dense, they're not nearly massive enough to collapse further into black holes, and are typically not too much more massive than our own Sun. Depending on magnetism and angle towards our system, we call them "pulsars".

I speculate it could be a passing neutron star that could give this world its ocean of molten metal.

(It is said that the most common element on Earth, aside from hydrogen and oxygen, is aluminum.)

d.m.f.

[Michael Kilderry]

Thanks, you've given me lots of good ideas, I'll see if I can try to include them all somehow in the description of the planets of Sirius I'm planning on including with the addon.

My version of how planet Elddim starts with the planet being close to a star that went supernova. It then got blown out of the system and accreted some heavy elements along the way. Eventually it found it's way into the Sirius planetary system, and there it became a Cytherean planet with a bit of a twist.

Of course, none of this is very realistic, but I'm thinking of the idea of splitting my Sirius addon into two different versions. A realistic one and a fantasy one.

The realistic version would have Elddim as more of an average Cytherean world. The lead seas would be turned into dry plains, possibly where oceans once existed. The fantasy version would include Elddim in it's present state with the liquid oceans and bizarre history.

As for the other planet, Renni would be included in it's present condition in the realistic version. In the fantasy version I could add some fancy stuff, like rivers of mercury (since Renni is a Mercury type planet) and some volcanoes which I may be able to include in the realistic version.

So what do you think of that idea?

[Malenfant]

I did however, state that Sirius B could be the source for exotics on any world orbiting Sirius A, being that B is a white dwarf, a collapsed stellar core smaller than the Earth. (A is also listed as a "metal rich" star.)

Why? White dwarfs are the cores of stars that haven't gone on to produce elements heavier than carbon (and lead is a LOT heavier than carbon). The only way you'd get lead is from a supernova.

I speculate it could be a passing neutron star that could give this world its ocean of molten metal.

How? Neutron stars can't just dump matter on any planets they pass, and if a neutron star is "passing" then it's not got a nebula full of heavy metals associated with it. Even if the planet did pass through such a nebula it wouldn't pick up THAT much lead.

(It is said that the most common element on Earth, aside from hydrogen and oxygen, is aluminum.)

This site states that in the Earth's crust at least Oxygen is most common, and then Silicon (which makes sense given that most rocks are silicates in them), and then Aluminium. Hydrogen is #10 on the list. I can't find any tables of elemental abundances for the whole Earth online at the moment, annoyingly enough - just of minerals/compounds. If you go here you'll see that there's about 100 times more Si in the solar system than Al, but that doesn't say much about the Earth's bulk composition.

Besides, Aluminium is a comparatively light metal that IIRC does not require supernova explosions to form. Lead on the other hand can only be formed in a supernova.

[Malenfant]

My version of how planet Elddim starts with the planet being close to a star that went supernova. It then got blown out of the system and accreted some heavy elements along the way. Eventually it found it's way into the Sirius planetary system, and there it became a Cytherean planet with a bit of a twist.

How did it get 'blown out of the system' it formed in? It couldn't form around the star that went supernova since those are too massive and short-lived to have planets. And after its journey (during which its atmosphere would have frozen solid since it has no star to warm it up, so it'd have to melt), when it arrived at Sirius it would have had to be captured into an inner orbit somehow, which would probably screw up the orbits of the planets around it (which would be very young worlds. In fact, the general likelihood that a star as shortlived as Sirius could capture any such planets is incredibly low).

Maybe what you suggest is the 'fantasy' version of events, but I'm mentioning this so you're aware that you have to consider things you probably haven't even thought of if you're making a realistic version.

[Michael Kilderry]

Yep, that's the fantasy version of events. In the realistic version, Elddim's just one of the planets which naturally formed around the Sirius star. In the realistic version, the lead oceans are just dry plains.

EDIT:

As for a description of the Sirius system, I've started my own little wiki website at Bluwiki, (http://www.bluwiki.org/go/Sirius). I picked Bluwiki since I like the wiki style and format there used on Wikipedia and other sites, but this also means that everyone can edit the pages. You're allowed to, but I would prefer that additional ideas for planets and other major changes be discussed on the discussion pages first, and approved by me before everyone starts changing the original pages too drastically.

[NoXion]

I personally think too much emphasis is being placed on realism, at the expense of imagination. Having a world with oceans of lead and clouds of sulphur? Cool, a world I would pay to visit.
A extrasolar version of Venus? Yawn. Pass the butter.

I don't know whether Michael's intentions are more towards realism or not, but correct me if I'm wrong his works lean to the latter.

This is not to deny that some "brainbugs" are not only scientifically laughable, but a sign of sheer laziness. For example, take completely one-note worlds that are nothing but a single type of terrain (Forest, grasslands etc)
Thankfully I have not seen such worlds in any Celestia addon, but too strict an insistence on scientific accuracy can give worldbuilders and imagineers tunnel vision IMHO, with similar results - a series of samey solar systems.
Something that I think using a little imagination can help to avoid that.

Just my 0.02.

[Malenfant]

Thankfully I have not seen such worlds in any Celestia addon, but too strict an insistence on scientific accuracy can give worldbuilders and imagineers tunnel vision IMHO, with similar results - a series of samey solar systems.

Look at the sheer variety of worlds we have in our own solar system, and then tell me that sticking to scientific accuracy limits a worldbuilder. I don't think it does at all.

My point was though that you could have worlds made out of meringue for all I care, so long as you make it clear that such worlds can't exist in reality. The danger is when you try to come up with an explanation for those that sounds realistic but actually isn't, because then you're misleading yourself and anyone else that such worlds are actually possible when they're not.

[ajtribick]

Point is, while the universe is undoubtebly full of surprises, there are some areas in which it seems to be extremely conservative. Chemistry seems to be one of them - there are only so many elements which are produced in reasonably high proportions in the universe, and that limits the chemistry out of which you can form planets.

Observations of forming solar systems have revealed olivine in the dust, which implies that any planets formed out of these discs will have similar chemistry to the terrestrial planets in our system. To my knowledge, there are no dust discs known which have belts of carbide dust (to go on to form carbon planets), and that is one of the more likely alternative chemistries.

Is this overly restrictive? I don't think so. Even with planetary chemistry from our system, you can end up with some extremely weird objects, such as hot Jupiters covered in sodium vapour, ice worlds with nitrogen cryovolcanism, iron planets, hypervolcanic sulphur moons, ammonia-water oceans beneath the surface of outer system worlds, planets which go from ice age to global hothouse each orbit, ocean worlds...

[NoXion]

You are right, but I've always felt disappointed that certain types of stars aren't very friendly to planet formation - I absolutely loved the Eta Carina addon, and was devastated to find out it was completely unrealistic
I would like to see a lot more addons released for the named stars in our sky, as well as unusual solar systems to go with unusual/exceptional stars, such as pulsar systems, white dwarf systems, brown dwarf systems, supergiant systems, you get my drift.

[Michael Kilderry]

I agree with NoXion, I think creating an interesting fantasy system is better than making a boring but realistic one.

I'm starting to think I should just have a fantasy Sirius system and not bother creating a realistic version. It's more fun for me that way.

[PlutonianEmpire]

I've already bothered with Deneb. Admittedly, it's quite unrealistic for a terran world to evolve by itself around a star like that, but one can dream, can't he?

[NoXion]

Is the Deneb system available for download?

[PlutonianEmpire]

Is the Deneb system available for download?

Not really.

But then again, I probably could upload it....

However, Many of the worlds there use textures that belong to someone else, so uploading would probably cause copyright rules violations.

[Malenfant]

I agree with NoXion, I think creating an interesting fantasy system is better than making a boring but realistic one.

Have you ever considered that you can make an interesting realistic one?

Again, how the heck can you call realism "boring"? Look at our own solar system! We've got a tidelocked world in a 3:2 resonance, a greenhouse world with amazing geology that once had oceans on it, a planet that barely survived a collision with a huge impactor billions of years ago to make it the garden world it is today, a small world with frozen oceans under its dusty surface, two hydrogen giants (one with an incredible ring system), a hypervolcanic moon, three moons with huge oceans of saltwater under their ice crust (two of which are bigger than a couple of the planets in the system, one of which has cracks forced open and shut every orbit by tides), a moon with a thick nitrogen atmosphere, a tiny cryovolcanically active moon, a moon that nearly was shattered by a large impactor, two icy giants (one of them tipped on its side), a patchwork moon, one large captured satellite with a thin atmosphere, an asteroidal satellite with a hugely eccentric orbit, and a small world where the atmosphere only forms when its close to the sun and that has one fully tidelocked satellite and two tiny ones beyond it.

And you can really look me in the proverbial eye and say that's BORING? To be honest, I think that kind of statement shows both a lack of knowledge about how amazingly interesting the bodies in our solar system are, and also a lack of imagination about what is actually possible in our universe. You seem to leap for the fantastic and ignore - and worse, dismiss - the vast possibilities of what is real.

[Cham]

I fully and TOTALLY agree with Malenfant.

The real world is the ultimate Fantasy and SF world. Nature always goes beyond human's imagination. SF and Fantasy are always late.

[Michael Kilderry]

I agree with NoXion, I think creating an interesting fantasy system is better than making a boring but realistic one.

Have you ever considered that you can make an interesting realistic one?

Again, how the heck can you call realism "boring"? Look at our own solar system! We've got a tidelocked world in a 3:2 resonance, a greenhouse world with amazing geology that once had oceans on it, a planet that barely survived a collision with a huge impactor billions of years ago to make it the garden world it is today, a small world with frozen oceans under its dusty surface, two hydrogen giants (one with an incredible ring system), a hypervolcanic moon, three moons with huge oceans of saltwater under their ice crust (two of which are bigger than a couple of the planets in the system, one of which has cracks forced open and shut every orbit by tides), a moon with a thick nitrogen atmosphere, a tiny cryovolcanically active moon, a moon that nearly was shattered by a large impactor, two icy giants (one of them tipped on its side), a patchwork moon, one large captured satellite with a thin atmosphere, an asteroidal satellite with a hugely eccentric orbit, and a small world where the atmosphere only forms when its close to the sun and that has one fully tidelocked satellite and two tiny ones beyond it.

And you can really look me in the proverbial eye and say that's BORING? To be honest, I think that kind of statement shows both a lack of knowledge about how amazingly interesting the bodies in our solar system are, and also a lack of imagination about what is actually possible in our universe. You seem to leap for the fantastic and ignore - and worse, dismiss - the vast possibilities of what is real.

Read my post more carefully. I said realistic BUT boring, not realistic IS boring. If it WAS boring I wouldn't be into planets and space at all would I? Where would my inspiration come from?

And it's not just making it interesting, it's originality too. I can't just make a near-identical replica of Saturn or Uranus and be happy with the result.

I'll probably make my solar systems fantasy rather than attempt to be realistic from now on since it is easier and doesn't cramp my impossible imaginative ideas as much.

[Malenfant]

Read my post more carefully. I said realistic BUT boring, not realistic IS boring. If it WAS boring I wouldn't be into planets and space at all would I? Where would my inspiration come from?

And it's not just making it interesting, it's originality too. I can't just make a near-identical replica of Saturn or Uranus and be happy with the result.

You're still missing the point, I think. You don't have to make a "realistic BUT boring" system. YOU are the one limiting yourself there, because you think that a realistic system would by necessity be a boring one too. Doesn't matter how you spin it, that's what "realistic BUT boring" means.

So, you can't make a near-identical replica of Saturn or Uranus and be happy with the result? Then don't do that - but you can still make interesting worlds that are very different to them that remain possible and realistic. Just because you can't imagine them doesn't mean they doin't exist, it's just a case of learning more about how Worldbuilding works.

I'm speaking from experience here. I started building worlds (on paper, using rules from an scifi pen-and-paper roleplaying game called Traveller) about 18 years ago (ack! Has it really been that long?!)! As time went on I realised that the worlds I were making weren't realistic, so I started to learn more about the worlds in our solar system and about how worlds (and stars) formed and evolved. Now I've got a rather realistic worldbuilding system of my own and a ton of scientific papers and notes on the subject, and know far more about the formation and evolution of stars and planets than is probably healthy .

But if you just want to sit there and make worlds with lead oceans and electric planets and other things that can't possibly exist, then you're never going to learn anything about how the universe really works. Using Celestia as a glorified sketchpad for outlandish, utterly impossible ideas is somewhat missing the point of it, I feel.

I'll probably make my solar systems fantasy rather than attempt to be realistic from now on since it is easier and doesn't cramp my impossible imaginative ideas as much.

But don't you see that the fact that you prefer to make impossible "interesting" fantasy systems instead of possible "interesting" realistic systems seems to imply that you DO find real planets and what's really out there to be boring? If that wasn't the case, you'd be making them realistic because you'd find that interesting, wouldn't you?

Again, what's wrong with having POSSIBLE imaginative, interesting ideas?

[Michael Kilderry]

Read my post more carefully. I said realistic BUT boring, not realistic IS boring. If it WAS boring I wouldn't be into planets and space at all would I? Where would my inspiration come from?

And it's not just making it interesting, it's originality too. I can't just make a near-identical replica of Saturn or Uranus and be happy with the result.

You're still missing the point, I think. You don't have to make a "realistic BUT boring" system. YOU are the one limiting yourself there, because you think that a realistic system would by necessity be a boring one too. Doesn't matter how you spin it, that's what "realistic BUT boring" means.

You're missing the point too. "A realistic but boring addon", in the way I used the words, is just a way to describe some hypothetical addon that is realistic, but boring at the same time. I'm not trying to say anything beyond that like realistic is boring or most realistic addons ARE boring or less interesting than the average addon. I am quite aware that "Impossible fantasy but boring" and "Realistic but interesting" are likely scenarios for addons too.

So, you can't make a near-identical replica of Saturn or Uranus and be happy with the result? Then don't do that - but you can still make interesting worlds that are very different to them that remain possible and realistic. Just because you can't imagine them doesn't mean they doin't exist, it's just a case of learning more about how Worldbuilding works.

But the problem with creating a realistic, interesting and original planet for me is that my imagination often makes up good ideas that don't end up possible at all, and since I don't really mind whether an addon is realistic or not (both can have interesting and original ideas) a good idea for a planet is a good idea, and so the addon becomes a fantasy.

I'm speaking from experience here. I started building worlds (on paper, using rules from an scifi pen-and-paper roleplaying game called Traveller) about 18 years ago (ack! Has it really been that long?!)! As time went on I realised that the worlds I were making weren't realistic, so I started to learn more about the worlds in our solar system and about how worlds (and stars) formed and evolved. Now I've got a rather realistic worldbuilding system of my own and a ton of scientific papers and notes on the subject, and know far more about the formation and evolution of stars and planets than is probably healthy .

Yes, but I'm still learning about all the complicated physics of the universe, and so when I come up with an idea, it often doesn't end up being something possible but then I don't want to change it because I worked hard and it looked really good, and so, the addon then becomes a fantasy.

But if you just want to sit there and make worlds with lead oceans and electric planets and other things that can't possibly exist, then you're never going to learn anything about how the universe really works. Using Celestia as a glorified sketchpad for outlandish, utterly impossible ideas is somewhat missing the point of it, I feel.

One of the main points of using Celestia is to have fun with it, I say, and a lot would agree, and I think you would too . I will continue make weird sci-fi worlds if it makes me happy, but, I do have an interest in how the universe works as well. This would be one of the reasons why I am interested in the universe and Celestia as well.

I'll probably make my solar systems fantasy rather than attempt to be realistic from now on since it is easier and doesn't cramp my impossible imaginative ideas as much.

But don't you see that the fact that you prefer to make impossible "interesting" fantasy systems instead of possible "interesting" realistic systems seems to imply that you DO find real planets and what's really out there to be boring? If that wasn't the case, you'd be making them realistic because you'd find that interesting, wouldn't you?

Again, what's wrong with having POSSIBLE imaginative, interesting ideas?

Nothing at all. Some of the reasons why I make fantasy addon instead of fact I have already explained. The fact is I find both fantasy AND fact interesting, and therefore there will be both in my addons.

In conclusion, what makes my fantasy addons fantasy is the inclusion of worlds that don't abide by the laws of physics. Although, this doesn't mean that you can't find a bit of realism here and there either.