[Space] GURPS Handbook of the Planets
 

A while ago I was working on a game aid to take most of the drudgery out of generating star systems and planets using the star system and world generation sequences in GURPS Space 4e. The project has ground to a halt as a result of unresolved errata on p.117 of Space, and I no longer have any interest in completing it. However, a number of forum members have said nice things about the last beta version, and others seem to want whatever help they can get with the large task of generating a system. So I have decided to make the last beta version, beta21, available on an abandonware basis.

My GURPS Handbook of the Planets is an Excel workbook without macros. It will open and run okay in Open Office and perhaps other spreadsheet programs capable of importing Excel workbooks.

The Handbook implements the Basic and Advanced starsystem generation and planet generation sequences up to the point of calculating economic volume, provided that the user specifies TL and population. A carrying capacity is calculated if the user specifies TL, but population is not calculated. Spaceport class, government type, and installations are not calculated: I decided that those were too specific to setting parameters and GM intentions to be worth troubling with.

The Handbook does implement features of the GURPS Space system generation sequence that allow the user to choose some of the features of the system (e.g. mass, number, and age of the star[s], arrangement of gas giants, mass, orbital radius, and orbital eccentricity of the 'first' gas giant) and have others generated randomly. It also implements features that allow the user to design a planet and insert it into a randomly-generated system, and to choose the basic features of a designed planet and have the details filled in at random. However, the user cannot generate the 'early' features of a planet randomly and then step in to choose later features. And if a designed planet be placed in circumstances where the orbital mechanics dictate that it will be tide-locked, the parameters affected by tidal locking over-ride input parameters.

The Handbook is so designed that the user's chosen "personal user number" and a "system number" for the system are combined to make a seed for the generation of pseudo-random numbers. That means that if the user puts in the same settings at different times, or if two different users put in the same settings, the Handbook will re-create the exact same system.

This version is released as an incomplete beta version, with no warranty as to fitness for purpose. It is an amateurish game aid, unsuitable for commercial use, and you ought not to rely on it for any important purpose.

Known issues

• The interface is a bit clunky, requiring the user to type accurately input that would be better selected from menus.
• An uncorrected erratum in the rule for volcanic activity, which produces division-by-zero errors in the case of star systems with age 0, has been hacked by trapping the errors and assigning the highest level of volcanic activity.
• I could not implement the rule for assigning orbital radii to moons without using a macro, so I arbitrarily chose a different method, in which the orbits of moons are spaced out like those of planets in a star system.
• I have replaced the official method for assigning bodies' initial periods of rotation with one of my own devising, which avoids the misconception that small bodies tend to rotate slower than large ones even when not braked by tides.
• There being no official corrections for the acknowledged errors in the formulas for tides and tidal braking, I have made and used unofficial corrections.
• In the nature of an unofficial improvement, the Handbook makes tide-locked bodies tide-lock to whatever raises the largest component of their tides, rather than their sun or innermost moon.
• Following GURPS Space, the Handbook does not reckon that tide-locked planets and planets with very long days have their habitability diminished by those features, beyond the effect of any reduction of atmospheric pressure and ocean coverage.

Easter eggs

• The Handbook calculates the equilibrium temperature of a planet or moon at aphelion and perihelion in its orbit. This calculation does not take account of the damping effect of the thermal inertia of the atmosphere and oceans, but it does give some indication of the effects of orbital eccentricity.
• The Handbook calculates the level of illumination at the surface of each planet, taking into account the bolometric correction (i.e. taking account of how much of the starlight is invisible IR and UV).
• For the sun and any moons of a planet, and the sun and primary planet of any moon, the Handbook calculates their apparent diameter (how big they look in the sky), their apparent period of rotation, and the amplitude of their contribution to the equilibrium tide.

If anyone who maintains a repository of GURPS material on-line, in some place where players are likely to find it, wishes to put up a copy of this game aid on their site, that is fine with me. If you do so, would you please post an announcement in the forums, for example with a post in this thread.

Important notices

• I do not propose to finish this game aid or to make further improvements or corrections.
  
• GURPS Space is a trademark of Steve Jackson Games, and its rules and art are copyrighted by Steve Jackson Games. All rights are reserved by Steve Jackson Games. This game aid is the original creation of Brett Evill and is released for free distribution, and not for resale, under the permissions granted in the Steve Jackson Games Online Policy.

Re: [Space] GURPS Handbook of the Planets
 

More known issues

• In Open Office (but not in Excel) there is a bug that produces multiple "#NA" and "#div/0" errors when inserting a designed planet that has a major moon.

Re: [Space] GURPS Handbook of the Planets
 

If I had the will and the time it probably wouldn't be impossible to write an actual program that would generate a system with a single click. Couple it with a random system name generator and a way to randomly assign coordinates and it could theoretically churn them out by the... whatever number you needed on a hex or Cartesian grid.

In fact I recall one based on Space 2nd on the Macintosh Classic platform.

Re: [Space] GURPS Handbook of the Planets
 

Of course it wouldn't be impossible. Meanwhile, you can use this. Or not, if you prefer.

You will probably want to put the output into an SQL database, or something like that.

What I do with this beast is to add a sheet into which I put a data table that feeds ten thousand consecutive numbers into the "system number" or "universe number", and then treats selected cells (spectral class, maximum habitability, gravity of the world with highest habitability, number of worlds with habitability 4+) as output. On my Mac this will update in about twenty minutes (or a list of only a thousand systems in two minutes). Then I can pick anything interesting out of the list and re-generate it. Or attach colour-coded system numbers to points on maps or names in lists. If necessary, I can fine-tune the search by using the control panel.

Another of my tricks is to attach a sheet including data from a star catalogue (I use HYG for this purpose). Then a couple of LOOKUP statements will import data from the catalogue into the control panel, and then a data table will produce a list of nearby stars with chosen characteristics such as the habitability of their most-habitable planet or moon. This list can be copied and sorted to produce a list of, say, habitable planets in a chosen version of the universe, and the details of the systems can be re-created knowing the universe number and system number.

Re: [Space] GURPS Handbook of the Planets
 

I tend to use "plot-generated" systems, i.e. whatever the plot demands, but mostly due to a lack of time to generate large numbers of systems, investigate them for story-friendly features, then build a story around them. Not that I don't have a use for something like this and actually I can see how it would be useful in an upcoming game I'm planning.

All of that is well beyond what I'm capable of doing right now. I only know enough programming to know what I'm reading when I see source code; I would rather leave the heavy lifting of coding to the CS majors.

Re: [Space] GURPS Handbook of the Planets
 

Don't no one be dissing the Bret-meister. I for one appreciate the in depth attention to accuracy and sheer hard work he put in for us ungrateful slobs.

Re: [Space] GURPS Handbook of the Planets
 

I'm sure there are 19,000 registered users on the forums who do not wish to use this aid. You don't all have to post to tell me so.

I'm equally sure that the members list includes several hundred better programmers than me who could produce a better product if they had the time and were willing to spend it. That's fine. I'll say it myself to save you all the trouble.

I am also perfectly aware that the approach I took in designing this thing was eccentric to the edge of madness, and makes it very difficult to maintain and modify, besides being downright weird. There you are. Point conceded. No need to flog a dead horse.

So if you find it useless, awkward, clumsy, a folly to have begun and madness to have carried through, just ignore the damned thing, okay? There's no need to pee in the punchbowl.

I'm out of here.

Re: [Space] GURPS Handbook of the Planets
 

I've used the heck out of it personally.

Re: [Space] GURPS Handbook of the Planets
 

In case that was not clear enough:

The star system generation sequence in GURPS Space is no mere random generator. It has a monstrously clever feature that allows you to generate a world to your liking by choosing results in the World Design Sequence in chapter 4 (basic world building) and then it inserts your planet into its correct place in a star system using the Star System Generation Sequence in chapter 5 (advanced world building).

This feature is implemented in my GURPS Handbook of the Planets.

It does take rather more than one click to tell the workbook what you want, but it will guide you through the ranges of possibility for designing a planet and its moons, and then it will insert the planet you have designed into a system orbiting either a random star or a star with any characteristics you specify.

Re: [Space] GURPS Handbook of the Planets
 

Thank you for sharing this. I truly appreciate your effort, and you making the result available.

Downloaded.

(Do you, by any chance, have a game aid which will allow me to generate one or two additional players?)

Re: [Space] GURPS Handbook of the Planets
 

This. It's an excellent tool, and I do not doubt that it took a daunting amount of work to produce.

That really requires a hardware rather than a software solution, and I'm going to stop before taking that joke any further.

Re: [Space] GURPS Handbook of the Planets
 

I was really looking for a short-term solution anyway.

Re: [Space] GURPS Handbook of the Planets
 

Brett,

Glad to see you back.

Too bad you aren't staying.

Illegitimi[1] non carborundum.

Regards,
Martin
[1] Myself included.

Re: [Space] GURPS Handbook of the Planets
 

The internets? I think that if I suffered from a paucity of players, I'd seriously try to run a game with MapTools (or similar).

QFT.

Re: [Space] GURPS Handbook of the Planets
 

In the 1st 1,000 systems in Universe 1, the these have affinity 5+.

• System 12 world IV, a cool standard garden planet with 60% hydrographics, standard breathable atmosphere, and 0.8 gee. G1 V star. Hab: 8 RVM: 0. Day: 23.3 hours.
• System 390 world I, a cool standard garden planet with 75% hydrographics, standard breathable atmosphere, and 0.99 gee. M4 V star. Hab: 8 RVM: 0. Tide-locked.
• System 877 world I, a warm standard garden planet with 75% hydrographics, standard breathable atmosphere, and 0.8 gee. M2 V star. Hab: 8 RVM: 0. Tide-locked.
• System 257 world III, a warm standard garden planet with 60% hydrographics, standard marginal atmosphere, and 0.81 gee. G2 V star. Hab: 7 RVM: 1. Day: 24.4 hours.
• System 397 world I, a normal standard garden planet with 60% hydrographics, standard marginal atmosphere, and 0.8 gee. M4 V star. Hab: 7 RVM: 1. Day: 1589.8 hours.
• System 476 world III, a tropical standard garden planet with 65% hydrographics, standard breathable atmosphere, and 1.04 gee. K2 V star. Hab: 8 RVM: -1. Tide-locked.
• System 90 world III, a cool standard garden planet with 90% hydrographics, standard marginal atmosphere, and 0.59 gee. K5 V star. Hab: 7 RVM: 0. Day: 6645.7 hours.
• System 311 world VI, a chilly standard garden planet with 50% hydrographics, standard breathable atmosphere, and 0.92 gee. F5 V star. Hab: 7 RVM: 0. Day: 16.7 hours.
• System 401 world I, a normal standard garden planet with 80% hydrographics, dense marginal atmosphere, and 0.98 gee. M1 V star. Hab: 7 RVM: 0. Tide-locked.
• System 455 world III, a warm standard garden planet with 65% hydrographics, standard marginal atmosphere, and 0.74 gee. K5 V star. Hab: 7 RVM: 0. Tide-locked.
• System 728 world IV, a cold standard garden planet with 70% hydrographics, standard breathable atmosphere, and 0.8 gee. K2 V star. Hab: 7 RVM: 0. Day: 35.7 hours.
• System 822 world IV, a cool standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.7 gee. G2 V star. Hab: 7 RVM: 0. Day: 579.1 hours.
• System 893 world II, a normal standard garden planet with 75% hydrographics, standard marginal atmosphere, and 0.92 gee. M1 V star. Hab: 7 RVM: 0. Tide-locked.
• System 787 world II, a hot standard garden planet with 25% hydrographics, standard breathable atmosphere, and 0.85 gee. M0 V star. Hab: 6 RVM: 1. Tide-locked.
• System 62 world I, a chilly standard garden planet with 55% hydrographics, standard breathable atmosphere, and 0.95 gee. M1 V star. Hab: 7 RVM: -1. Tide-locked.
• System 180 world II, a tropical standard garden planet with 80% hydrographics, dense marginal atmosphere, and 1.06 gee. M2 V star. Hab: 7 RVM: -1. Tide-locked.
• System 241 world II, a cool standard garden planet with 65% hydrographics, standard marginal atmosphere, and 0.73 gee. M1 V star. Hab: 7 RVM: -1. Tide-locked.
• System 351 world III, a cool standard garden planet with 60% hydrographics, thin breathable atmosphere, and 0.67 gee. G1 V star. Hab: 7 RVM: -1. Day: 655.1 hours.
• System 48 world I, a cool standard garden planet with 50% hydrographics, thin breathable atmosphere, and 0.89 gee. M2 V star. Hab: 6 RVM: 0. Day: 3423.1 hours.
• System 59 world VIII, a cold standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.73 gee. F5 III star. Hab: 6 RVM: 0. Day: 16.7 hours.
• System 93 world II, a warm large garden planet with 100% hydrographics, very dense marginal atmosphere, and 1.45 gee. M2 V star. Hab: 6 RVM: 0. Day: 2357 hours.
• System 255 world II, a hot standard garden planet with 65% hydrographics, standard marginal atmosphere, and 0.71 gee. K5 V star. Hab: 6 RVM: 0. Tide-locked.
• System 406 world II, a normal standard garden planet with 90% hydrographics, dense marginal atmosphere, and 0.8 gee. M2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 425 world II, a chilly standard garden planet with 35% hydrographics, standard marginal atmosphere, and 0.84 gee. M2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 434 world II, a hot standard garden planet with 45% hydrographics, standard breathable atmosphere, and 0.98 gee. M1 V star. Hab: 6 RVM: 0. Tide-locked.
• System 469 world III, a tropical standard garden planet with 45% hydrographics, standard marginal atmosphere, and 0.72 gee. K2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 694 world I, a cool standard garden planet with 90% hydrographics, very thin breathable atmosphere, and 0.71 gee. M6 V star. Hab: 6 RVM: 0. Day: 599.7 hours.
• System 695 world IV, a very cold standard garden planet with 75% hydrographics, standard marginal atmosphere, and 0.69 gee. K2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 848 world V, a chilly standard garden planet with 60% hydrographics, thin breathable atmosphere, and 0.73 gee. G1 V star. Hab: 6 RVM: 0. Day: 17.1 hours.
• System 799 world II, a hot standard garden planet with 70% hydrographics, standard marginal atmosphere, and 0.61 gee. M1 V star. Hab: 5 RVM: 1. Day: 2688.9 hours.
• System 411 world I, a warm standard garden planet with 80% hydrographics, thin breathable atmosphere, and 0.76 gee. M4 V star. Hab: 7 RVM: -2. Day: 1173.3 hours.
• System 192 world I, a very hot standard garden planet with 65% hydrographics, standard marginal atmosphere, and 0.89 gee. M4 V star. Hab: 6 RVM: -1. Tide-locked.
• System 509 world IV, a warm standard garden planet with 50% hydrographics, thin breathable atmosphere, and 0.69 gee. G1 V star. Hab: 6 RVM: -1. Day: 15.3 hours.
• System 519 world I, a chilly standard garden planet with 90% hydrographics, very thin breathable atmosphere, and 0.63 gee. M2 V star. Hab: 6 RVM: -1. Day: 3313.1 hours.
• System 530 world IIc, a chilly standard garden moon with 80% hydrographics, thin marginal atmosphere, and 0.56 gee. G0 V star. Hab: 6 RVM: -1. Day: 154.7 hours.
• System 568 world III, a normal standard garden planet with 45% hydrographics, standard marginal atmosphere, and 0.92 gee. K5 V star. Hab: 6 RVM: -1. Tide-locked.
• System 648 world III, a frozen standard garden planet with 75% hydrographics, standard breathable atmosphere, and 0.96 gee. M0 V star. Hab: 6 RVM: -1. Tide-locked.
• System 756 world V, a normal standard garden planet with 80% hydrographics, very thin breathable atmosphere, and 0.76 gee. G0 V star. Hab: 6 RVM: -1. Day: 17.7 hours.
• System 865 world II, a warm standard garden planet with 25% hydrographics, standard marginal atmosphere, and 0.9 gee. M2 V star. Hab: 6 RVM: -1. Tide-locked.
• System 118 world II, a very cold standard garden planet with 60% hydrographics, thin breathable atmosphere, and 0.8 gee. G2 V star. Hab: 5 RVM: 0. Day: 29.6 hours.
• System 144 world II, a tropical standard garden planet with 100% hydrographics, standard marginal atmosphere, and 0.97 gee. G2 V star. Hab: 5 RVM: 0. Day: 50.3 hours.
• System 191 world V, a very cold standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.76 gee. G0 V star. Hab: 5 RVM: 0. Day: 13.4 hours.
• System 234 world II, a chilly standard garden planet with 20% hydrographics, very thin breathable atmosphere, and 0.6 gee. M1 V star. Hab: 5 RVM: 0. Tide-locked.
• System 251 world I, a tropical standard garden planet with 30% hydrographics, very thin breathable atmosphere, and 0.74 gee. M4 V star. Hab: 5 RVM: 0. Tide-locked.
• System 272 world I, a normal standard garden planet with 50% hydrographics, very thin breathable atmosphere, and 0.91 gee. M4 V star. Hab: 5 RVM: 0. Tide-locked.
• System 330 world II, a cool standard garden planet with 50% hydrographics, thin marginal atmosphere, and 0.57 gee. K2 V star. Hab: 5 RVM: 0. Day: 10095 hours.
• System 436 world II, a cool standard garden planet with 20% hydrographics, very thin breathable atmosphere, and 0.74 gee. K4 V star. Hab: 5 RVM: 0. Tide-locked.
• System 567 world I, a cool standard garden planet with 40% hydrographics, very thin breathable atmosphere, and 0.75 gee. M6 V star. Hab: 5 RVM: 0. Tide-locked.
• System 582 world III, a frozen standard garden planet with 60% hydrographics, thin breathable atmosphere, and 0.97 gee. K2 V star. Hab: 5 RVM: 0. Day: 31.8 hours.
• System 643 world III, a cool standard garden planet with 50% hydrographics, dense marginal atmosphere, and 1.04 gee. G0 V star. Hab: 5 RVM: 0. Day: 15.5 hours.
• System 653 world II, a tropical standard garden planet with 40% hydrographics, very thin breathable atmosphere, and 0.84 gee. M1 V star. Hab: 5 RVM: 0. Tide-locked.
• System 700 world III, a very cold standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.71 gee. M0 V star. Hab: 5 RVM: 0. Day: 5886.1 hours.
• System 712 world II, a cool standard garden planet with 10% hydrographics, very thin breathable atmosphere, and 0.8 gee. M2 V star. Hab: 5 RVM: 0. Tide-locked.
• System 773 world III, a very cold standard garden planet with 55% hydrographics, standard breathable atmosphere, and 0.95 gee. M1 V star. Hab: 5 RVM: 0. Tide-locked.

Re: [Space] GURPS Handbook of the Planets
 

In the 2nd thousand systems in Universe 1, these have habitability 5+

• System 1006 world I, a normal standard garden planet with 65% hydrographics, standard breathable atmosphere, and 0.77 gee. M1 V star. Hab: 8 RVM: -1. Tide-locked.
• System 1047 world I, a cool standard garden planet with 90% hydrographics, standard breathable atmosphere, and 0.92 gee. M5 V star. Hab: 8 RVM: 0. Day: 981.5 hours.
• System 1381 world I, a warm standard garden planet with 90% hydrographics, dense marginal atmosphere, and 0.92 gee. M4 V star. Hab: 8 RVM: 0. Tide-locked.
• System 1519 world III, a warm standard garden planet with 80% hydrographics, standard breathable atmosphere, and 1 gee. K2 V star. Hab: 8 RVM: 0. Day: 6285.6 hours.
• System 1531 world I, a normal standard garden planet with 90% hydrographics, standard breathable atmosphere, and 1.05 gee. M1 V star. Hab: 8 RVM: -1. Day: 3173.6 hours.
• System 1585 world II, a cool standard garden planet with 70% hydrographics, standard breathable atmosphere, and 0.81 gee. K5 V star. Hab: 8 RVM: 0. Day: 5508.2 hours.
• System 1886 world VII, a tropical standard garden planet with 60% hydrographics, standard breathable atmosphere, and 0.84 gee. G0 III star. Hab: 8 RVM: 0. Day: 13.3 hours.
• System 1995 world II, a cool standard garden planet with 75% hydrographics, standard breathable atmosphere, and 0.92 gee. M2 V star. Hab: 8 RVM: 0. Tide-locked.
• System 1041 world IV, a chilly standard garden planet with 60% hydrographics, standard marginal atmosphere, and 0.79 gee. K2 V star. Hab: 7 RVM: -1. Day: 293.2 hours.
• System 1043 world IIb, a cold standard garden moon with 90% hydrographics, standard breathable atmosphere, and 0.87 gee. G0 V star. Hab: 7 RVM: 1. Day: 59.8 hours.
• System 1206 world I, a cold standard garden planet with 80% hydrographics, standard breathable atmosphere, and 0.87 gee. M1 V star. Hab: 7 RVM: 0. Day: 4574 hours.
• System 1209 world I, a normal standard garden planet with 60% hydrographics, thin breathable atmosphere, and 0.57 gee. M4 V star. Hab: 7 RVM: 0. Day: 1276.3 hours.
• System 1265 world II, a tropical standard garden planet with 55% hydrographics, standard breathable atmosphere, and 0.9 gee. M0 V star. Hab: 7 RVM: -2. Tide-locked.
• System 1427 world V, a warm standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.73 gee. G0 IV star. Hab: 7 RVM: 0. Day: 503.2 hours.
• System 1484 world II, a chilly standard garden planet with 75% hydrographics, standard marginal atmosphere, and 0.78 gee. M1 V star. Hab: 7 RVM: 0. Tide-locked.
• System 1491 world III, a chilly standard garden planet with 50% hydrographics, standard breathable atmosphere, and 0.81 gee. M0 V star. Hab: 7 RVM: 0. Day: 5508.4 hours.
• System 1495 world V, a normal standard garden planet with 90% hydrographics, standard marginal atmosphere, and 0.82 gee. G0 V star. Hab: 7 RVM: 0. Day: 14.7 hours.
• System 1538 world I, a cool standard garden planet with 45% hydrographics, standard breathable atmosphere, and 0.75 gee. M1 V star. Hab: 7 RVM: 0. Tide-locked.
• System 1540 world IV, a chilly standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.73 gee. G0 IV star. Hab: 7 RVM: 0. Day: 13.5 hours.
• System 1608 world V, a warm standard garden planet with 50% hydrographics, standard breathable atmosphere, and 1.09 gee. G0 V star. Hab: 7 RVM: -1. Day: 12 hours.
• System 1647 world I, a cool standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.82 gee. M4 V star. Hab: 7 RVM: -1. Day: 1403.1 hours.
• System 1829 world I, a chilly standard garden planet with 75% hydrographics, standard marginal atmosphere, and 0.83 gee. M6 V star. Hab: 7 RVM: 0. Tide-locked.
• System 1834 world IIIa, a cold standard garden moon with 70% hydrographics, standard breathable atmosphere, and 1.03 gee. G0 V star. Hab: 7 RVM: -1. Day: 222 hours.
• System 1896 world I, a normal standard garden planet with 90% hydrographics, standard marginal atmosphere, and 0.74 gee. M1 V star. Hab: 7 RVM: 0. Day: 3354.1 hours.
• System 1105 world II, a tropical standard garden planet with 70% hydrographics, thin marginal atmosphere, and 0.64 gee. M1 V star. Hab: 6 RVM: 0. Day: 2885.9 hours.
• System 1128 world IV, a cold standard garden planet with 70% hydrographics, thin breathable atmosphere, and 0.65 gee. K2 V star. Hab: 6 RVM: -2. Day: 1609.4 hours.
• System 1190 world II, a cold standard garden planet with 70% hydrographics, thin breathable atmosphere, and 0.68 gee. M2 V star. Hab: 6 RVM: 0. Day: 3671.5 hours.
• System 1199 world II, a cold standard garden planet with 55% hydrographics, standard breathable atmosphere, and 0.92 gee. M1 V star. Hab: 6 RVM: 0. Tide-locked.
• System 1284 world I, a cold standard garden planet with 90% hydrographics, thin breathable atmosphere, and 0.69 gee. M2 V star. Hab: 6 RVM: -1. Day: 3712.3 hours.
• System 1314 world IVa, a hot standard garden moon with 70% hydrographics, standard marginal atmosphere, and 0.85 gee. G0 IV star. Hab: 6 RVM: 0. Day: 66.7 hours.
• System 1317 world II, a warm standard garden planet with 35% hydrographics, standard marginal atmosphere, and 0.66 gee. M2 V star. Hab: 6 RVM: -1. Tide-locked.
• System 1354 world III, a hot standard garden planet with 25% hydrographics, standard breathable atmosphere, and 1.07 gee. K2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 1371 world II, a cool standard garden planet with 35% hydrographics, standard marginal atmosphere, and 0.69 gee. M1 V star. Hab: 6 RVM: 0. Tide-locked.
• System 1397 world I, a warm standard garden planet with 45% hydrographics, standard marginal atmosphere, and 0.88 gee. M2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 1456 world II, a warm standard garden planet with 55% hydrographics, standard marginal atmosphere, and 0.81 gee. M2 V star. Hab: 6 RVM: 0. Tide-locked.
• System 1555 world II, a chilly standard garden planet with 90% hydrographics, very thin breathable atmosphere, and 0.52 gee. M2 V star. Hab: 6 RVM: 1. Day: 3466.4 hours.
• System 1599 world IV, a cold standard garden planet with 80% hydrographics, thin breathable atmosphere, and 0.94 gee. K2 V star. Hab: 6 RVM: -1. Day: 9849.5 hours.
• System 1966 world IV, a hot standard garden planet with 80% hydrographics, dense marginal atmosphere, and 0.95 gee. G0 IV star. Hab: 6 RVM: 0. Day: 17.2 hours.
• System 1973 world V, a warm standard garden planet with 100% hydrographics, standard breathable atmosphere, and 0.92 gee. G0 V star. Hab: 6 RVM: 0. Day: 30 hours.
• System 1012 world I, a tropical standard garden planet with 40% hydrographics, dense marginal atmosphere, and 0.89 gee. M6 V star. Hab: 5 RVM: 0. Tide-locked.
• System 1060 world IV, a cold standard garden planet with 50% hydrographics, thin breathable atmosphere, and 0.74 gee. K2 V star. Hab: 5 RVM: 2. Day: 24.6 hours.
• System 1077 world I, a chilly standard garden planet with 40% hydrographics, very thin breathable atmosphere, and 0.65 gee. M2 V star. Hab: 5 RVM: -1. Tide-locked.
• System 1331 world II, a normal standard garden planet with 40% hydrographics, very thin breathable atmosphere, and 0.69 gee. M1 V star. Hab: 5 RVM: 0. Tide-locked.
• System 1385 world III, a very cold standard garden planet with 70% hydrographics, thin breathable atmosphere, and 0.69 gee. K5 V star. Hab: 5 RVM: 0. Day: 7930 hours.
• System 1401 world V, a warm standard garden planet with 80% hydrographics, thin marginal atmosphere, and 0.57 gee. G0 IV star. Hab: 5 RVM: 0. Day: 517.4 hours.
• System 1470 world II, a tropical standard garden planet with 10% hydrographics, very thin breathable atmosphere, and 0.79 gee. M1 V star. Hab: 5 RVM: -2. Tide-locked.
• System 1472 world III, a normal standard garden planet with 30% hydrographics, very thin breathable atmosphere, and 0.61 gee. K5 V star. Hab: 5 RVM: 1. Tide-locked.
• System 1604 world II, a normal standard garden planet with 100% hydrographics, standard marginal atmosphere, and 0.92 gee. M0 V star. Hab: 5 RVM: 0. Day: 3546.5 hours.
• System 1649 world I, a cold standard garden planet with 70% hydrographics, thin marginal atmosphere, and 0.53 gee. M2 V star. Hab: 5 RVM: -1. Day: 4485.7 hours.
• System 1682 world II, a warm standard garden planet with 10% hydrographics, very thin breathable atmosphere, and 0.79 gee. M2 V star. Hab: 5 RVM: 0. Tide-locked.
• System 1817 world I, a cold standard garden planet with 35% hydrographics, standard marginal atmosphere, and 0.75 gee. M6 V star. Hab: 5 RVM: 0. Tide-locked.
• System 1842 world II, a normal standard garden planet with 70% hydrographics, very dense marginal atmosphere, and 0.98 gee. M2 V star. Hab: 5 RVM: 0. Tide-locked.
• System 1908 world II, a chilly standard garden planet with 100% hydrographics, thin breathable atmosphere, and 0.81 gee. M2 V star. Hab: 5 RVM: 0. Day: 2809.4 hours.
• System 1947 world Id, a cold standard garden moon with 50% hydrographics, thin breathable atmosphere, and 0.82 gee. G0 V star. Hab: 5 RVM: 0. Day: 183.8 hours.
• System 1997 world II, a chilly standard garden planet with 30% hydrographics, very thin breathable atmosphere, and 0.79 gee. M1 V star. Hab: 5 RVM: 0. Tide-locked.

Re: [Space] GURPS Handbook of the Planets
 

Among Systems 2,001 to 12,000 of Universe 1, the following are of great interest:

• System 6952, a F5 V star with 2 habitable planets
• System 7946, a K4 V star with 2 habitable planets
• System 3791, a M1 V star with 2 habitable planets
• System 6190, a M1 V star with 2 habitable planets
• System 11908, a K2 V star with 2 habitable planets
• System 7823, a G0 V star with 2 habitable planets
• System 7868, a G0 V star with 2 habitable planets
• System 8770, a M1 V star with 2 habitable planets
• System 9163, a K4 V star with 2 habitable planets
• System 11284, a K4 V star with 2 habitable planets
• System 5250, a G0 IV star with 2 habitable planets
• System 5794, a G1 V star with 2 habitable moons
• System 11637, a G2 V star with a habitable planet and a habitable moon
• System 10980, a G0 III star with a habitable planet and a habitable moon

Re: [Space] GURPS Handbook of the Planets
 

Let's take a look at that System 5794:
It's that old standard, a gas giant in the Goldilocks zone, with multiple habitable moons.

Here's World IIIa, the watery moon:

And here's IIIc, the moon with actual dry land.

Re: [Space] GURPS Handbook of the Planets
 

Here's System 10980 in Universe 1
Note that Planet V is in a state of mutual tide-lock with its habitable moon, Va. Also, the habitable planet VI is mutually tide-locked to its moon, but the moon is not habitable. The two inner asteroid belts are full of valuable minerals: at TL 10 they will each support a couple of billion belters.

Let's take a look at the sheet for Va.

The sky here is going to be pretty. Not only is there that M2 stalking slowly around the outer system, but the primary looks about four times as big as the Sun does from Earth, and Planet V is fixed in the sky and looks three times the size of Earth's Moon.

Note that despite Planet V's strong tidal effects of Moon Va, the resulting tides do not rise or fall. That's because Va is tide-locked, and does not rotate through its tidal bulges. the mantle will have time to adjust fully, and Va will be the same shape as its oceans (i.e. prolate on the axis aligned with V).

Re: [Space] GURPS Handbook of the Planets
 

Well, that's about enough of generating huge numbers of systems and skimming through the results. It took my quaint little computer about half an hour of actual running time to generate those 12,000 systems, which is pretty shocking, and shows how inefficient my approach is. But still, it does work.

Now let's take a look at designing a planet and inserting it into a system. I'm going to try to see how close to its star I can get a habitable planet.

Close to the star means hot, which means that the light molecules in the atmosphere will tend to escape. I'm going to want to make the escape velocity as high as I can to keep the atmosphere where it ought to be. I think this means that I actually want a standard planet, not a large one. Let's see.

I try a standard garden world with a breathable atmosphere. I give it a thin atmosphere in the hopes that that will keep it cool in close to the star. I choose 90% hydrographics to keep the Habitability as high as possible in the face of high temperatures. The control panel tells me that the temperature range ought to be 250 to 340 Kelvins: I put in 340 to keep as close to the star as possible. That's 67 C average surface temperature. I must say that I marvel that that is considered habitable at all: even the polar regions must be nearly 40 C. Never mind.

I'm offered a range of densities from 0.8 to 1.2, I try 0.8. The machine offers me a range of gravities from 0.65 to 1.39. I try 0.65. The machine (which is assuming an F2 V star for the moment) tells me that the orbital radius will be 1.30 AU. I try 1.39 gravities: no change.

I backtrack and see whether high density will help (it ought to raise the escape velocity at given mass, not that I have given mass). Density 1.2. Now I'm allowed gravity 0.53 to 1.13. It shouldn't matter, but I try both extremes.It doesn't matter, and I'm still at 1.30 AU.

Okay, time to backtrack even further: will a dense atmosphere actually help?

Put in 1.8 for the primordial atmospheric mass. Options for density don't change. I try the minimum and maximum gravities. Orbital radius works out 1.97 at each extreme. So a dense atmosphere does not confound expectations. Back to minimum atmospheric mass. It looks as though the closest I can get this standard world to its (F2) star is 1.3 AU.

I try very quickly with a large garden planet. It turns out not to make a difference. So I assign an orbital eccentricity (0), and axial tilt (11°), a primordial day length of 16 hours, and (on a whim) choose to have no major moons and two moonlets. I pick a RVM of 2 to make up for the fact that this place is only marginally habitable, and assign both volcanism and tectonics moderate.

Putting in TL10 and population equal to carrying capacity I get a planet sheet like this:

Re: [Space] GURPS Handbook of the Planets
 

I rarely if ever use this expression, but Oh.. My.. God!
You are one awesome man, Brett. If we wanted kids, I would ask you to impregnate my girlfriend.

Re: [Space] GURPS Handbook of the Planets
 

Now to see how many habitable worlds we can get in the outer reaches of a system with this object at the inner edge of the Goldilocks Zone. I figure that we want a solitary star with a conventional arrangement of gas giants, to have the most planets and smallest eccentricities. Also, we want the system old (so that planets will have the best chance to make the Ocean->Garden transformation. And that means a low-mass, dimmish star so that it will have a long lifespan. But a star older than the Galaxy would be silly. I reckon on 10 billion years as enough. A quick experiment shows me that a mass 1.05 star will have become a subgiant at that age, but mass 1 is still okay. My designed planet will tide-lock, but that won't (officially speaking) alter its Habitability.

System sheet looks like this:
So I generate a thousand systems with this set-up, and find two with three habitable planets (Systems 648 and 376) besides 251 with two habitable worlds.

Re: [Space] GURPS Handbook of the Planets
 

The system sheet for System 648 under all those custom settings looks like this:

Re: [Space] GURPS Handbook of the Planets
 

And its planets like this:

and

Re: [Space] GURPS Handbook of the Planets
 

Could someone fiddle with this to come up with a system I want? Other than Brett, you've done enough incredible wonderful work.

I want a two garden world system, in which one is a large cool to warm planet, and one is a warm to hot relatively low gravity one.
I can't seem to to reproduce Brett's results by just putting in the system and universe numbers. I know, I'm an Open Office moron.

Re: [Space] GURPS Handbook of the Planets
 

Well, that's certainly an unusually flattering thing to say, but perhaps it's best if the offer remains hypothetical.

It would be easiest to design one planet and run off a few systems to find the other one you want.

Just to be clear: when you say "large" do you mean "having a diameter similar to Earth or larger" or "having significant helium in the atmosphere"?

Odd. Perhaps Open Office is doing something differently from the way Excel does it.

Re: [Space] GURPS Handbook of the Planets
 

Just a large garden planet as in larger than earth but still habitable without a ridiculously dense atmosphere.
The stars seem to match, but most of them have only ocean worlds if that.

Re: [Space] GURPS Handbook of the Planets
 

Odd. The two possibilities that leap to mind are that you are using a previous version that you downloaded while I was testing a couple of years ago or that you have put an entry into a cell on the control panel and not blanked it. If it's neither of those, then it begins to look as though either your computer does arithmetic differently from mine and is getting different pseudorandom numbers from the same seed or as though Open Office implements some functions differently from Excel.

Try this.

1. Download a fresh copy of the workbook.
   
2. Save a backup copy somewhere safe.
   
3. Open a working copy of the fresh download.
   
4. On the "control panel" sheet, enter as follows:
   • Personal user number: 1
   • Use US Customary units: FALSE
   • campaign technology level: 10
   • Number of stars: 1
   • arrangement of gas giants: conventional
   • world type: standard
   • subtype: garden
   • primordial atmospheric mass: 1.5
   • hydrographic coverage: 80
   • average surface temperature: 280
   • density: 0.8
   • surface gravity: 1.12
   • orbital eccentricity: 0.01
   • obliquity: 15
   • primordial day length: 28
   • number of major moons: 0
   • number of moonlets: 1
   • resource value modifier: 0
   • vulcanism: light
   • tectonics: moderate
   Note well that if you fill in any cells in "User Specified Planet" you must fill all of them to get correct results.
   
5. On the "system table" sheet, enter the number 754 into cell F4 (next to "system number").

Does the resulting system suit your requirements?

You ought to get a system table matching this:

Re: [Space] GURPS Handbook of the Planets
 

Perfect. It must be a difference in the random numbers.
Thanks.

Re: [Space] GURPS Handbook of the Planets
 

No, if it's working now then it was probably the change of version or else you had modified some cell (e.g. on the control panel) and not put it back. That's easy enough to do, and it is the reason why it is important to keep an unmodified original download in a safe place and never alter it.

Re: [Space] GURPS Handbook of the Planets
 

Seconded. The HotP is fantastic; the fact that Brett is distributing it freely, even more so. I only wish I had more free time to test it exhaustively.

Good to see you back, Brett.

M.

Re: [Space] GURPS Handbook of the Planets
 

Whereas this is precisely what works best for me. I've found I'm quite good at looking at a large sample of random data and building settings and stories by free association of suitable samples (the massive UPP lists in the several Traveller incarnations, which in the beginning I considered a waste of space, turned out to be one of the most useful parts of the books for me). The HotP is perfect for that.

M.

Re: [Space] GURPS Handbook of the Planets
 

I will second Mercator's post. I have a set of campaigns that I want to use the Orion Spur as the setting for. The astrography is going to matter to me since that is what will determine the spread of colonisation efforts, resource allocation, invasion routes, etc. Working with Astrosynthesis I can get the positions of stars down to current precision (yeah I know that isn't saying much for ones outside a certian radius). Add in a GURPS specific planet generator and I can work out likely boundaries for polities and species with different requirements and tweak the results along the way. Space Empire "A" been around half a million years? Enough time to reform marginal worlds so bump some of those up to "garden". I need to play with this. Thanks again Brett.

Re: [Space] GURPS Handbook of the Planets
 

Do you have a good set of data for the nearby stars in a convenient form? Common names, Bayer/Flamsteed designation, position, spectral class, luminosity, mass, and age where known? I'd find that very handy. Especially if it came with the semi-major axes and eccentricities of orbits in multiple systems.

Re: [Space] GURPS Handbook of the Planets
 

Good Lord! Has it really been three months since I put this up? Why have I accomplished nothing in that time?

Has anyone been making use of it? War stories?

Do you think that planetological detail such as star system generators produce actually makes a difference to the course or outcome of SF RPG adventures? I had a conversation yesterday with a chap who suggested that they don't, and therefore are a waste of time. I answered I value what they contribute to the background, the verisimilitude it provides to have background detail settled, and the sense of otherworldliness that an alien setting can give even it it doesn't have any tactical effects. But I would like to know that he is wrong, that adventures being set on an un-Earthly world can turn out differently because of that.

Re: [Space] GURPS Handbook of the Planets
 

I have played around with it, much like I did with VE2 and will do once we get VDS and as I did with G:Space 4e and pen and paper and a pocket calculator. Not so much preparing for games, but more like solitaire or one player Civilization. My group is playing fantasy and an end of the present campaign is not in sight, so it may be quite some time before we start a SF campaign.

I personally absolutely want planetological details. If I wanted just some rough ideas I could have stayed with Classical Traveller or GURPS Space 2e. Whether they will have practical effects once I get to use some of those planets I don´t know. But I want them. Besides, it´s a lot easier not to use something that´s there, than to create something that´s not there.

Re: [Space] GURPS Handbook of the Planets
 

The best bet is probably the Hipparcos-Yale-Gliese catalogue: http://www.astronexus.com/node/34

This will get you spectral class and abs magnitude, from which you should be able to derive luminosity (http://en.wikipedia.org/wiki/Luminos..._and_magnitude). Not age, though.

Re: [Space] GURPS Handbook of the Planets
 

They certainly do to me - even without immediate game-mechanical effects, it helps me as GM to know that there's a proper basis for this particular world being cold and that one being hot, that this one has high density (aha, so there are probably minerals there worth having) and that one has an exotic atmosphere. In my newest campaign I've been getting adventure ideas inspired directly by details of stellar system and spaceship design.

Re: [Space] GURPS Handbook of the Planets
 

I'm using it my fantasy game! Of course it's definitely a fantasy game with some SF sensibilities. I'm finding it very useful to differentiate the 13 planets on which the game takes place. I don't think I would have been willing to use the rules in Space for this without your spreadsheet.

Absolutely. Firstly there are game mechanical effects of Gravity, air pressure, and so on. Without planetological detail, I'd likely just forget about them, making every place to be exactly like Earth. Secondly there are the atmospheric details. When I describe the place, how many moons are there? How many suns?

Re: [Space] GURPS Handbook of the Planets
 

My best at present is the ISBD database. (With permission from the author) I downloaded the database files, which has a lot of the required data (except that continual discovery of extrasolar planets keeps putting that data out of date), but the formats are a bit inconvenient.

ISDB does have mass and age and metallicity where these have been determined.

Re: [Space] GURPS Handbook of the Planets
 

I haven't done very much with your sheet beyond a quick look-see, but this is actually a really easy fix, with a little bit of time invested (I do lots of menu's in my GURPS Spaceships Design Spreadsheet).

In Excel 2000: Data (menu) -> Validation
In Excel 2007/10: Data (tab) -> Validation
In OpenOffice: Data (menu) -> Validity

In all of them, in the Validation window, you can select List for the type of Validation. In the list entry box you can create a comma separated list in Excel; in OpenOffice you put each entry for the list on it's own line. In either you can also set the list to be a Cell Range instead, so you can create dynamically changing lists by changing the target cell values (or, in the case of Excel, so you can create list entries which include a comma - the list is comma deliminated in Excel, so values with comma's are not allowed in the simple list, but are within a Cell Range).

Other Validation options can be useful to restrict cell values to decimals, integers, as well as numbers above, below, or between given values, and a few other options. Validation is really useful for this kind of sheet.

Re: [Space] GURPS Handbook of the Planets
 

I ought to look into it.

Things would have been rather easier if I had boned up on that bit of Excel first. Would have saved me a lot of trouble on input filtering and error messages. Which were not exactly easy the way I did them (though by no means as tricky as some of the other things I did in that monster of a workbook).

Re: [Space] GURPS Handbook of the Planets
 

Brett, have you checked out Tycho-2? I think it supersedes all the catalogs I've seen in this thread. It has a much larger scope than you need, but many entries are better-reduced data from Hipparcos, so you might find it useful. I think it's the best catalog so far until we get GAIA in 8-9 years.

M.

Re: [Space] GURPS Handbook of the Planets
 

It doesn't seem to have parallax, which is a pest.

Re: [Space] GURPS Handbook of the Planets
 

I don't suppose anyone could give me a few hints on how to do something like this in OpenOffice? Paging through systems manually is tedious

Re: [Space] GURPS Handbook of the Planets
 

Is anyone still using my spreadsheet?

Has anyone made a proper computer instance of the GURPS 4e star system generation sequence yet?

Re: [Space] GURPS Handbook of the Planets
 

I still, and will always, love it to bits.

Sadly, I have little computer ability to tweek or create programs.

Re: [Space] GURPS Handbook of the Planets
 

Has anyone put a copy up for download on a GURPS website that people are going to be able to find?

Re: [Space] GURPS Handbook of the Planets
 

I'm using it from time to time. Haven't uploaded or improved on it, though.

Re: [Space] GURPS Handbook of the Planets
 

Yes. Quite happily, and with ongoing gratitude.

Not me.

Re: [Space] GURPS Handbook of the Planets
 

Not me. But IMNSHO this would be a really good addition for

http://www.sjgames.com/gurps/resources.html

Re: [Space] GURPS Handbook of the Planets
 

I'm taking a class in Java programming right now and one of the things I am going to do afterwards is moving all my little rpg tools there. This will include a dice roller and the star system generation system from Space and whatever else I have or can be persuaded to add. As time permits.

Re: [Space] GURPS Handbook of the Planets
 

I still use it quite happily, although simple mass generation of systems still eludes me. I've taken a stab or two at re-writing it as a real program but given up in despair each time (I am not a skilled programmer).

Re: [Space] GURPS Handbook of the Planets
 

I have a variation on the 4e planet generation system.

Its wrong somewhere, but it mostly works. Generating orbits to fill is a fairly hard task for binary stars.

Re: [Space] GURPS Handbook of the Planets
 

Yes. Mostly with an OpenOffice makro that searches a couple hundred systems and prints out those over a certain Hab score.

Off and on I write a bit on my console garden world generator, but so far I haven't found a good and simple algorithm for the "fiddle around with the orbits to fit the pre-generated world's orbit in" part of step 22.

Re: [Space] GURPS Handbook of the Planets
 

I don't suppose you could share this macro? I've been trying to write something similar myself.

Re: [Space] GURPS Handbook of the Planets
 

Sure. The first caveat is the usual "The software is provided "as is", without warranty of any kind, express or implied, including but not limited to...." spiel. It's only a OO macro, but don't use this on a machine controlling the nuclear reactor Homer Simpson.

Second caveat is that I suck at user interfaces. The paths and the parameters User# and boundaries of the system# are all hard coded.

Usage:
1) Change "H:\RPG_kram\GURPS\BHoP\" in line 30 and 58 into the paths you're actually using.
2) Change the parameters in lines 8, 10, 12 and 14 to your liking.
3) Save and run. I would first make a test run with 50 or so to see how long your computer needs for that.

Re: [Space] GURPS Handbook of the Planets
 

Thanks for this! Now that I've had a chance to play with it it works great! Going to make it much easier to generate liveable star systems when my group rolls back to a space opera game.

Re: [Space] GURPS Handbook of the Planets
 

I've been working on it, but it's currently bogged down by 3 things

1. Having it safely pick out orbitals is a pain. I may have to deviate from the rules (by having it place the pregenerated Gas Giant AFTER the orbitals.)

2. Moons? Yeah, not liking that either

3. Rewriting the objects so I can more easily troubleshoot things.

That said, I plan to have it out.. soon. I think. :/

(I will also probably release it online after I add a "force rule purism" option, since I implement a few house rules.)


ETA: Side note, I actually have to admit I have no clue what forumlae to use for tides. I do note they still keep generating too high values for my tastes, but any variation I do on that will be a "not default" option.

Re: [Space] GURPS Handbook of the Planets
 

I'd probably use it more if I didn't have to special order a4 paper to print it on.

Re: [Space] GURPS Handbook of the Planets
 

Why do you need A4 paper? It scales to fit on letter just fine.

Re: [Space] GURPS Handbook of the Planets
 

Then that's new since the last time I used it, it even says on the version I'm using that it is designed for A4 paper, and usually will cut off some parts (beyond the parts that are listed as always being cut off).

Re: [Space] GURPS Handbook of the Planets
 

It's not a feature of the spreadsheet, it's a feature of the program. I use LibreOffice and when printing you're given the option to scale the output to fit the page — admittedly, you have to dig a bit for it.

Re: [Space] GURPS Handbook of the Planets
 

Yes. It is a thing of joy and beauty. Thank you for making it.

Re: [Space] GURPS Handbook of the Planets
 

You need to special-order ISO-approved paper? ô_ò

Re: [Space] GURPS Handbook of the Planets
 

Try printing purchased letter-sized GURPS pdf's on A4 paper... soooo much white spaaaaaaaaaaace.....

Re: [Space] GURPS Handbook of the Planets
 

Who would distribute metric paper in a country where everyone has inch-spec printers, binders etc.?

Re: [Space] GURPS Handbook of the Planets
 

My cheap-and-rusty printer accepts letter as well as A4 and other specs. (Tested recently because I somehow ended up in possession of a single package of Letter-sized paper.) No idea about binders since I don't have one at home. And anyway, that seems to mean that any high paperwork dealing with the international community would require a special order. That's . . . weird.

Re: [Space] GURPS Handbook of the Planets
 

Oh, my printer will take it, but I'd be hard pressed to find an office supply store within a couple hundred* miles that actually carries A4 paper. It is a specialty paper type in the US.


*I'd be hard pressed to find a decent office supply store (ie not walmart or kmart) in less than 80 miles.

Re: [Space] GURPS Handbook of the Planets
 

Sounds like an oddity with your program or printer driver; if I print from a program there's almost always a 'scale to fit' button hiding somewhere.

Re: [Space] GURPS Handbook of the Planets
 

Could be. I'm using Office 2010, Excel.

Re: [Space] GURPS Handbook of the Planets
 

Printer driver then; for the printer I have access to at the moment there's a 'scale to fit' option under Print->Properties->Effects, but what you get when you choose Properties depends on the printer.

Re: [Space] GURPS Handbook of the Planets
 

I did lay out the results pages and set their print areas so that those pages will fit on an A4 page, which makes the tables too tall and perhaps slightly too wide for US letter paper, unless a "shrink to fit" feature of the program and printer driver be used. That much is a feature of the sheet.

Re: [Space] GURPS Handbook of the Planets
 

I'll have to give a look for shrink to fit then, I use it regularly on other programs.

Re: [Space] GURPS Handbook of the Planets
 

I've just built a version which, instead of randomly generating a star according to the rules in GURPS Space, given a system number N looks up the figures for the Nth star in the XHIP catalogue and uses those. (I added randomly generated data to fill in the blanks in the catalogue.)

This version has had the world type table, gas giant arrangement table, and planetary orbit eccentricity table tweaked to my requirements, and is rigged to generate systems only around stars of such type as according to my version of Stephen Dole's calculations have a real chance of having a habitable planet. But I could fix all that pretty easily.

Re: [Space] GURPS Handbook of the Planets
 

I love the version I've got of your spreadsheet, and if you share another, I would be eager to try it out. I am truly grateful for the Handbook. It saved me a lot of time in fleshing out my sf campaign last year, and I plan to employ it again when I do another space based game.

Re: [Space] GURPS Handbook of the Planets
 

Related note: did anyone ever submit errata for the giant luminostiy change? If not, I need to write it up and submit some.

(It's kinda badly wrong.)

Re: [Space] GURPS Handbook of the Planets
 

Edition 3 or edition 4?

I know on the simulator (4th edition) I have(wrote) I get lots of garden worlds around tiny red dwarfs that are very much NOT tide-locked. That actually seems to be the main kind of habitable system, in fact.

Re: [Space] GURPS Handbook of the Planets
 

4th. It's *25, and should be *10000.


As for that I don't often get it but I haven't really written the code to check habitable zones.

Re: [Space] GURPS Handbook of the Planets
 

Going through the file again, is there any known reason why Excel should lock it so that it can't be edited with a big red warning stating that editing it could damage my computer?