TSandman Posted January 11, 2008 Report Share Posted January 11, 2008 Hullo Fist, Pardon me for the long post... and the post in the wrong board (did not pay attention WHERE I posted the whole thing... /me is stoopid ) Second, being a new "Old" convert (I've played the games when it was only called Champion but rediscovered it a month ago) I'd like to say hi to everyone... and offer a possible gift... Lessee... I've been preparing a Traveller-esque game for my group and, owning almost everything Traveller, I stumbled upon Traveller Hero... 2 PDF, 5ER, Star Hero and some other purchase later, I've thrown the towel at designing Star System by Hand (No, I do NOT like those Traveller UPP... anyway, they would not fit IMTU ;p). Instead... I've cobbled up two nifty Perl script (cobbled as in Bail-wire and Duct Tape, I ain't a computer programmer, tho I dabble a bit in the art). I'm presently in the process of completing the 2nd script and will merge both thereafter. Since I'm using Star Hero star/planetary system generation extensively plus a bit of fiddling on my part, if the Powers That Be let me give it all to you, I'll do it. If not, well, I'd be willing to generate a few fully populated systems and give them to the community... What I have done so far: Script 1: Generate a star sector (20 x 20 x 20 LY) with solar system, populating said system with most of the star data available from the book. (I'm NOT generating Brown Dwarfs system as it would not be that usefull) What's left to do: Clean up the coordinates a tad, clear away "impossible orbits" Script 2: Takes the Orbit (in AU), Star Mass (in Solar Mass) and the Zone the orbit is in and generate orbital and physical properties of the planets and any moons/asteroid/rings orbiting it. It can generate every kind of planet and up to approximately 85 moons (I've beefed it up for the Supergiants, since even Jupiter has more moons than the bare system can generate) What's left to do: Athmosphere, Climate, Life, and Surface properties. Here are a sample system from the first script and a sample planet from the second... ----------------------------------------------------- 1 = 2, -5, -9 2 Stars # 1 ==> M0V Brightness 0.01, Solar Mass 0.305, Age 8500 M Yellow Zone 0.03, Green Zone 0.081, Blue Zone 0.132, Black Zone 2.036 Planetary Orbit 0: 0.3 Planetary Orbit 1: 0.5 Planetary Orbit 2: 0.7 Planetary Orbit 3: 1.1 Planetary Orbit 4: 1.9 Planetary Orbit 5: 3.5 Planetary Orbit 6: 6.7 Planetary Orbit 7: 13.1 # 2 ==> G0V, Distant Companion, Orbit: 6700 AU Brightness 1.064, Solar Mass 1.035, Age 6000 M Yellow Zone 0.266, Green Zone 0.83, Blue Zone 1.383, Black Zone 21.289 Planetary Orbit 0: 0.3 Planetary Orbit 1: 0.4 Planetary Orbit 2: 0.5 Planetary Orbit 3: 0.7 Planetary Orbit 4: 1.1 Planetary Orbit 5: 1.9 Planetary Orbit 6: 3.5 Planetary Orbit 7: 6.7 Planetary Orbit 8: 13.1 Planetary Orbit 9: 25.9 Planetary Orbit 10: 51.5 --------------------------------------------------- Planet ============================================= Periapsis (AU) = 0.95 Periapsis (km) = 151617977156.45 Apoapsis (AU) = 1.026 Apoapsis (km) = 163747415328.966 Eccentricity (%) = 8 Eccentricity (e) = 0.0384615384615385 Semi-Major Axis (AU) = 1.02524084340327 Semi-Major Axis (km) = 163626255552.607 Orbital Period (Std Years) = 1.13245204566182 Orbital Period (Std Days) = 413.635315528101 Orbital Speed (km/s)) = 28756.8174640546 Inclination (Deg) = 3.48860174132423 Longitude of Ascending Node = 112.770278791761 Argument of Periapsis = 347.553624907369 Mass = 1.15996992431969 Mass (kg) = 6.92919633991612e+24 Composition = Rock-Iron Density = 0.9 Radius (km) = 6933.3375590047 Diameter (km) = 13866.6751180094 Gravity = 9.62049446552839 Gravity (g) = 0.981017418336373 Escape Velocity (km/s) = 11.5500766762862 Rotation (Hours) = 23 Rotation (Days) = 1.04347826086957 Rotation Anomaly = None Axial Tilt (Deg) = 6 Zone = GREEN # of Moons = 1 Moon Orbits = 5 Moon # 1 ================================== Planetary Moon Periapsis (Radius) = 5 Periapsis (km) = 34666.6877950235 Apoapsis (Radius) = 5.3 Apoapsis (km) = 36746.6890627249 Eccentricity (%) = 6 Eccentricity (e) = 0.029126213592233 Semi-Major Axis (Radius) = 5.29775143177001 Semi-Major Axis (km) = 36731.0989801619 Orbital Period (Std Days) = 12.10562942412 Orbital Speed (km/s)) = 13902.9672334566 Inclination (Deg) = 6.09143548373867 Longitude of Ascending Node = 142.512710100064 Argument of Periapsis = 124.40135316438 Mass = 0.454350162112732 Mass (kg) = 2.71410612839662e+24 Composition = Rock-Iron Density = 0.9 Radius (km) = 5072.90813432767 Diameter (km) = 10145.8162686553 Gravity = 7.03901753161419 Gravity (g) = 0.717780030042287 Escape Velocity (km/s) = 8.45083301146114 Tidal Heating = 600 Rotation (Hours) = 0.00344192484396122 Rotation (Days) = 0.0826061962550692 Rotation Anomaly = Tidally Locked To Planet Axial Tilt (Deg) = 6 ------------------------------------------------- Any Comments??? Quote Link to comment Share on other sites More sharing options...
Dholcrist Posted January 11, 2008 Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Unfortunately, I completely lack any skill as to deciphering the scripts you've posted, but, from reading your description, this sounds like it'd be extremely useful. Bravo, I'll continue checking back to see how this turns out. And while I'm sure I'm not the first to welcome you to the boards (people 'round here tend to be rather on the ball with the friend-making), I'll go ahead and extend a big welcome anyways. So yeah, welcome! Quote Link to comment Share on other sites More sharing options...
Curufea Posted January 11, 2008 Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Nice. Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 11, 2008 Author Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Unfortunately' date=' I completely lack any skill as to deciphering the scripts you've posted, but, from reading your description, this sounds like it'd be extremely useful. Bravo, I'll continue checking back to see how this turns out.[/quote'] Well, those aren't scripts per see... they're the result of them... Let me walk you through them briefly. The first output is the Star System one... ok, it's *NOT* great, and in need of better layout Basically, it's the coordinates of the star system with brief description of all the stars in the system (I can generate up to 6 stars/system, in a triple binary configuration, that is three pairs of star orbiting each others) There are infos as the Spectral Class of the star, it's Mass, it's approximate age (needs work tho) the orbits where planets are found (or can be found) the limits for Yellow/Green/Blue/Black zone. The most interesting one is the second... it lists almost everything you might want to know for a planet, starting with it's orbital parameters, then it's physical ones... This means you know how long it takes the planet to do a complete orbit, a complete rotation, does it have moons and if so, how much, how far are they orbiting and what kind are they (planetary moons as our own, Rings, chunks of rocks...). Yeah, maybe it's going overboard for a RPG, but after spending two evening trying to do it by hand and seeing that I had sooooo many to go yet for my campain (and that I *DO* like to have real-looking stuff), well, I decided to automate it all And while I'm sure I'm not the first to welcome you to the boards (people 'round here tend to be rather on the ball with the friend-making), I'll go ahead and extend a big welcome anyways. So yeah, welcome! Thanks, and btw, you're actually the first... (well, at least the first welcome I've read ;p). I've been lurking for some weeks and from what I've seen, I think I'll like the place Ciao! Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 11, 2008 Author Report Share Posted January 11, 2008 Update: Star System Generation, Prebiotic Atmosphere I've complete the Prebiotic Atmosphere parameters... Here's what it looks, it's only shown when it's for a Planet or Planetary Moon with an atmosphere. ATMOSPHERIC PARAMETERS Prebiotic Atmosphere: Dense Prebiotic Pressure = 34.4597483926662 Ammonia = 7.50448761492972 Argon = 10.4627038248236 Carbon Dioxide = 9.17928135518705 Chlorine = 0 Fluorine = 0 Helium = 0 Hydrogen = 0 Methane = 29.9687188086353 Nitrogen = 42.8848083964244 Sulphur Dioxide = 0 Quote Link to comment Share on other sites More sharing options...
Doc Posted January 11, 2008 Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Definitely worth rep. I'll keep an eye on this. Quote Link to comment Share on other sites More sharing options...
culhwch Posted January 11, 2008 Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Very nice! I worked a bit last year on a C# desktop application to generate star systems, but time constraints got in the way of my finishing it. Well, that and writing code all day, I don't really feel like writing it at night. Anyway, looks good so far! Keep up the good work! Quote Link to comment Share on other sites More sharing options...
Bygoneyrs Posted January 11, 2008 Report Share Posted January 11, 2008 Re: Star System Generation (Now at the RIGHT place :/) Welcome aboard TSandman, And I too have Rep'd you as well too!!! Yes I also am on Comstar's discussion BB, and have played Traveller since it's beginning now...what 30 yrs! I last played Champions way back in v2, but about two years ago started buying everything for Hero System v5. I almost own it all now except for like 3 books it would seem. Yes I too have Traveller Hero, The New Era 1248, and etc. I have decided to convert my 25+ yr personal Traveller campaign based in the Verge subsector, to using the Hero System. I to like the 1248 Era as well. BUT I am using a changing the AI Virus to having released a TK Virus (Bio Virus likle that in I Am Legend movie) and spreading it through-out the Verge subsector. Throw in the effects of the AI Virus much of the region was reduced to rubble, if life survived at all. Also other Bio Viruses were released as well a kinda Zombie creating type like Resident Evil type too. What a mess...LOL!!! So for me your program looks very nice with the details it provides a planet. I should also say that part of the fun was designing out each system by hand one at a time and I loved it very much. Thus I did that for many of the systems already for the Verge subsector already. It might be fun to re do some of them and flesh out those that I have not done over the years that no one has bothered to jump into. Happy gaming, Penn:dyn Quote Link to comment Share on other sites More sharing options...
shadowcat1313 Posted January 12, 2008 Report Share Posted January 12, 2008 Re: Star System Generation (Now at the RIGHT place :/) very interesting work, I will also be following the progression of this have you looked at either of the free world generator programs for traveller? I know you dont like the traveller world gen system, but it might provide some ideas and inspiration theres Galactic 2.4 and Heaven and Earth you can find both here http://www.freelancetraveller.com/infocenter/swlist/winprogs.html if you need mac or linux software, there are some links also if you back up a link Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 15, 2008 Author Report Share Posted January 15, 2008 Re: Star System Generation (Now at the RIGHT place :/) Hullo Shadowcat... Yes, I've seen Heaven & Earth some years ago... but I just didn't like it that much... either way, I like the way Star Hero try *HARD* to do realistic systems (ie, it's not just "random" ) As for the generator I'm "Coding" (hacking up, bodging up whaterver the term for the mess I'm typing) I'm in the process of thinking how to code for the planetary atmosphere... I gotta put my mind around it soon, next gaming session's on next sunday ;p I Just took the w-e off, after 5 days of doing it, I need to see the forest from the trees... I'll keep you all posted Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 17, 2008 Author Report Share Posted January 17, 2008 Re: Star System Generation (Now at the RIGHT place :/) Latest Update: Atmosphere is done Takes into account the following Distance from Primary & Planet Mass Zone (Yellow/Green/Blue/Black) Albedo (very basic tho) Greenhouse Effect Tidal Heating for Moons Planet Tidally Locked to primary Planet with very slow rotation Assume basic life on worlds with temperature "Just Right" Gives the following: Atmospheric Pressure at 0 m. ** Atmospheric Composition for Prebiotic and Biotic atmosphere Temperature for Periapsis & Apoapsis (to take into account very eccentric orbits) Temperature at Polar and Equatorial latitude ** I would have calculated the Atmosphere "height", and at what altitude it would equal 1 STD Atmosphere, but lets say that I don't fully how to compute everything and which equations to use... SAMPLE: (Temp is in Kelvin, Pressure in STD Atmosphere, composition in %) ATMOSPHERIC PARAMETERS Atmosphere Standard, Biotic Atmosphere Pressure = 0.419463203466628 Ammonia = 0.137673431364626 Argon = 2.14055304963648 Carbon Dioxide = 33.5106382156052 Chlorine = 0 Fluorine = 0 Helium = 0 Hydrogen = 0 Methane = 8.79131551670847 Nitrogen = 50.3704010158361 Oxygen = 5.04941877084918 Sulphur Dioxide = 0 Temperature, Periapsis = 312.497695994799 Temperature, Periapsis (Equator) = 332.497695994799 Temperature, Periapsis (Polar) = 292.497695994799 Temperature, Apoapsis = 300.689055856721 Temperature, Apoapsis (Equator) = 320.689055856721 Temperature, Apoapsis (Polar) = 280.689055856721 ATMOSPHERIC PARAMETERS Atmosphere Dense, Prebiotic Atmosphere Pressure = 338.254482382128 Ammonia = 20.4710622855503 Argon = 0 Carbon Dioxide = 0 Chlorine = 0 Fluorine = 0 Helium = 6.09689021679125 Hydrogen = 9.00350834799525 Methane = 64.4285391496632 Nitrogen = 0 Sulphur Dioxide = 0 Temperature, Periapsis = 260 Temperature, Periapsis (Equator) = 280 Temperature, Periapsis (Polar) = 240 Temperature, Apoapsis = 246.969524988766 Temperature, Apoapsis (Equator) = 266.969524988766 Temperature, Apoapsis (Polar) = 226.969524988766 Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 17, 2008 Author Report Share Posted January 17, 2008 Re: Star System Generation (Now at the RIGHT place :/) What's Left as of now: The planet's surface: - Hydrosphere - Terrain - Resources - Maybe put Colonies? - Asteroids - Comets - Space Habitats ? Then it's cleaning up the code a bit, merging the two scripts into one Quote Link to comment Share on other sites More sharing options...
Doc Posted January 17, 2008 Report Share Posted January 17, 2008 Re: Star System Generation (Now at the RIGHT place :/) Ressources, well, mineral ressources should be proportionnal with the gravity of a planet, as it comes from its density. The more a planet is dense, the more it has mineral ressources and the higher is its gravity. Usually, the denser planets wil be nearer to the star. Terrain depends mainly on three things: is there an atmospher? Is there a hydrosphere? Is there a volcanic activity? Volcanic and tectonic activity will create large terrain features, while a dense atmosphere and a water cycle will smooth them. The presence of an atmosphere and a hydrosphere will also reduce the presence of craters on the surface. Well, hope this can help a bit. Keep up the good work! Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 18, 2008 Author Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) Thanks for the hints, but I'll stick to the Star Hero generation guidelines Oh, just some nitpicking Gravity doesn't come from Density, but from Mass... not that the two aren't related tho Denser objects tends to have more "Pull" due to the fact that most of the mass is "nearer" than less dense objects of same mass (thus being bigger, more mass is farther away from the other mass it's attracted to, giving it less attraction because of the inverse square law...) Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted January 18, 2008 Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) Latest Update: Atmosphere is done Takes into account the following Distance from Primary & Planet Mass Zone (Yellow/Green/Blue/Black) Albedo (very basic tho) Greenhouse Effect Tidal Heating for Moons Planet Tidally Locked to primary Planet with very slow rotation Assume basic life on worlds with temperature "Just Right" Gives the following: Atmospheric Pressure at 0 m. ** Atmospheric Composition for Prebiotic and Biotic atmosphere Temperature for Periapsis & Apoapsis (to take into account very eccentric orbits) Temperature at Polar and Equatorial latitude I'm no expert, but wouldn't perihelion & aphelion be more accurate terms for bodies orbiting a star? And it's good that you are taking into account orbital eccentricity. But what about axial tilt? Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted January 18, 2008 Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) Resources' date=' well, mineral resources should be proportional with the gravity of a planet, as it comes from its density. The more a planet is dense, the more it has mineral resources and the higher is its gravity. Usually, the denser planets will be nearer to the star.[/quote'] Density does not always equal mineral resource abundance. Many useful minerals/metals are quite light, like aluminum. Or all the abundance could be locked into the core -- or spread too thinly though the crust to be useful. IIRC, Earth's early oceans dissolved many minerals, especially iron. When the atmosphere & oceans became oxygenated by early life the iron oxidized and sedimented out, giving the modern world it's rich iron ore resources. Terrain depends mainly on three things: is there an atmosphere? Is there a hydrosphere? Is there a volcanic activity? Volcanic and tectonic activity will create large terrain features, while a dense atmosphere and a water cycle will smooth them. The presence of an atmosphere and a hydrosphere will also reduce the presence of craters on the surface. Atmospheric density depends upon more than just the surface gravity of the object. Venus in nearly identical to Earth in both size and surface gravity, yet has 92 times the atmospheric pressure. Volcanic gas releases are responsible for much of the atmosphere the rocky planets have, making it a two-edged geological sword. It both builds the terrain, and provides the atmosphere that works to tear it down. Quote Link to comment Share on other sites More sharing options...
Thia Halmades Posted January 18, 2008 Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) ::smashes TSandman over the head with his HICCoS:: Hello. I have no idea what the scripty stuff means. The bunneh'll come along and cut off your head later. Welcome (back) and to the boards! I'd give you the full intro but clearly you're actually trying to have an actual dialogue. Just wanted to pop in and say hi. kthxbai. Quote Link to comment Share on other sites More sharing options...
SteveZilla Posted January 18, 2008 Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) ::smashes TSandman over the head with his HICCoS:: Hello. I have no idea what the scripty stuff means. The bunneh'll come along and cut off your head later. Welcome (back) and to the boards! I'd give you the full intro but clearly you're actually trying to have an actual dialogue. Just wanted to pop in and say hi. kthxbai. Y'know, I think that's the first confirmed Drive-By Repping that I've seen. Quote Link to comment Share on other sites More sharing options...
Cancer Posted January 18, 2008 Report Share Posted January 18, 2008 Re: Star System Generation (Now at the RIGHT place :/) Looks real nice. Probably most of my comments reflect your source material rather than anything else. * If the atmosphere has oxygen, then methane is going to be at most a trace constituent. The reverse is also true. * At high temperatures, water can be an important atmosphere gas. * In what units are the planetary density? Tons/m^3 is what I'd expect, but looking at your numbers, it seems more likely to be relative to the Earth. * Unless they are very cold, terrestrial-mass planets cannot retain hydrogen and helium in their atmospheres for very long. * Tidal locking and orbit circularization tend to go together, though Earth's Moon is a prominent exception to this. The processes that give you tidal locking also work to circularize the orbit, and also (to a lesser extent) make the orbit coplanar with the main planet's equator. These processes operate most strongly on close moons and in systems with large planet/moon mass ratios. * I think you might be able to fake up terrain features and planetary resources via an ad hoc planetary heat reservoir relation. Small bodies tend to lose heat quickly, their geological activity halts, and their surfaces become dominated by impact cratering and interesting mineral deposits stop being produced. Other annoyances as I think of them Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 19, 2008 Author Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) @ SteveZilla I prefer using Periapsis and Apoapsis just because I'm using the same subroutines for Planets and Moons, but it'll probably change the output... Hell, it's only a case of Delete & Re-type Presently, Axial Tilt do not have a very big effect in my script, since it mostly has effect on seasons (I'm taking the Earth as an example, with its axial tilt always in the same direction, in regard to the Sun, it only does one full rotation per orbit). I do *NOT* think I'll be very usefull to go as far as calculating Nutation or other cyclic obliquity changes As for the Drive-By Repping, I'm still reeling from the impact hit and shivvering from the cold... But DAMNED, does it taste GOOD! Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 19, 2008 Author Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) @ Thia Thanks for the Yummy but Frosty welcome I'll let The Bunneh come along and I'll show him my nice Holy Grail Bunny Slippers... Dunno, maybe He'll fall in love with them (I'll be sure to wash them afterward tho) Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 19, 2008 Author Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) @ Cancer I know about water vapor, I just haven't got around including it yet... I might swap some $ of Methane for Water Vapor, since Methane (CH4) combines with Oxygen (O2) to produce CO2 and Water (H20). The Density is in "Standard Earth". I'll probably add kg/m3. I will probably add the planet\moon "Volume" too. As for Hydrogen\Helium, my output is only a sample... I might have tested the output by giving it a short radius ( ex: 1 AU) and putting it in a Blue Zone and keeping the Luminosity not realistic for that scenario I'm presently re-doing the output format so I can see what I generate better (in 2 column, so as to have 1 entire planet\moon on a single screen). For the Tidal Locking comment, I'm using plain Star Hero stuff... ie: orbits within .5 AU are much more susceptible to be Tidally locked. Granted, I might have to correct the Eccentricity of the planet's orbit after determining that it's tidally locked to the primary (That and Argument of Periapsis and the Logitude of the Ascending Node). Tidally locked moons are much more common with SH system, but I've put planetary moons further than 30 planetary radii on possible resonnant rotation. It's not perfect, but better than having them all tidally locked. I'd have to correct other orbital parameters for tidally locked moon, same as for planets... Again, I've used SH's system to generate Ressources. Bigger planets have more chance to generate Heavy Metals and Metals, etc.. further ones tend to generate more volatiles (Gaz Giant any one?)... I've passed on generating complexe life, animals, civilizations etc. That ought to be taken care by the GM, since it can vary much more widely than the rest depending on each GM's setting. Then again... That script is not even V1.0 Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 19, 2008 Author Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) Oh, I forgot I've completed the surface generation... Granted, it's only basic features (Hydrology, Mountains %, Ice-Cap % and "Desert"%) but it'll give a base for GM to put whatever they want on that bedrock Right now, the Planet Generation script is working pretty good, I'm only changing the output to have more understandable results. I might have to re-code some parts, since it's the biggest project I've done in Perl as of yet (I am *NOT* a coder, I have no *real* coding skills, so it's a bit of a mess As of now, the script is over 1600 lines long but is pretty complete by my standard... I've sumbled upon a Gas SuperGiant with over 40 moons today... with every moons generated unfortunately, since it was a random result, I didn't have the complete result in buffer and couldn't save it oh well, next time! I'll have to fiddle with the Sector Generation script too, since I've stumble onto a *VERY* basic and stoooopid bug... built into the SH Sector Generation system ... One of those DOH! Moments (Basically, I'm litterally replicating Dice Rolls.. and with +-1D10 for each coordinates, you are missing the ZERO coordinate... DOH!. I want it to output a distance matrice for the entire sector, a bit like those travel matrices you see in every travel books Quote Link to comment Share on other sites More sharing options...
Doc Posted January 19, 2008 Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) Atmospheric density depends upon more than just the surface gravity of the object. Venus in nearly identical to Earth in both size and surface gravity, yet has 92 times the atmospheric pressure. Volcanic gas releases are responsible for much of the atmosphere the rocky planets have, making it a two-edged geological sword. It both builds the terrain, and provides the atmosphere that works to tear it down. True, but it is not the only factor. Some jovian moons do have volcanic activity but don't "keep" their atmosphere around because of low gravity, as they are partly or mostly made of water ice, wich is less massive. Another exemple could be mars, wich does not have an iron core to make gravity as high as on earth. * Unless they are very cold, terrestrial-mass planets cannot retain hydrogen and helium in their atmospheres for very long. Same rason. A world of very high gravity could keep them. Another way would be to have a lower solar wind, as it is (at least for the nearer planets) the main agent of atmospheric loss. * Tidal locking and orbit circularization tend to go together, though Earth's Moon is a prominent exception to this. The processes that give you tidal locking also work to circularize the orbit, and also (to a lesser extent) make the orbit coplanar with the main planet's equator. These processes operate most strongly on close moons and in systems with large planet/moon mass ratios. It can happen too between different moons of a same planet if there are many. There are resonances between the revolutions of the jovian moons. * I think you might be able to fake up terrain features and planetary resources via an ad hoc planetary heat reservoir relation. Small bodies tend to lose heat quickly, their geological activity halts, and their surfaces become dominated by impact cratering and interesting mineral deposits stop being produced. It depends. Earth has a heatt reservoir provided it's relatively high composition in radioactive materials. Their decay keeps heating up the planetary mantle. This wasn't the case for Mars and now it's volcanic activity has stopped. Another way is tidal heating. Multiple tidal locks exerces a tension that can heat up a moon's interior, wich is the reason for volcanic activities in jovian moons. Well, I don't know if all those infos will be very usefull to TSandman, but, hey, it's my second Psychological limitation: cannot resist debating over scientific facts that is controling me right now. I like to do this because I can teach people something as much as I can learn from them. Think of me as a somewhat lesser Nyrath... Anyway, have fun! Quote Link to comment Share on other sites More sharing options...
TSandman Posted January 19, 2008 Author Report Share Posted January 19, 2008 Re: Star System Generation (Now at the RIGHT place :/) Well, I don't know if all those infos will be very usefull to TSandman, but, hey, it's my second Psychological limitation: cannot resist debating over scientific facts that is controling me right now. I like to do this because I can teach people something as much as I can learn from them. Think of me as a somewhat lesser Nyrath... Hehehe Well, Doc.. the Star Hero system does differentiate between Rock, Rock-Iron, Rock-Ice and some other planet type... AFAIK, it's the *Best* sector/system/planet generation system that I've found in any RPG... Pretty complete, that's why I'm using it as a base... Since I'm no Astronomer or Astrophysicist, I needed a base that was grounded in what we know (well, what we knew circa 2002 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.