Trade Classifications

[Malenfant]

I'd heard that Mars was listed as atm 3 because it had been a bit terraformed. Dunno if that's canonical or not, but there you go.

But technically, Mars as it is today should actually be atmosphere 0. "Trace" isn't actually very "trace" at all, since wherever I've seen pressures listed for atmospheres in later Trav products, Trace has been shown as 0.01 to 0.1 bars. Mars, on the other hand, has an atmosphere of about 0.006 bars (6 millibars, tops), which is less than the lowest possible for Trace. Triton would also be listed as atm 0, since its atmospheric pressure is only a few microbars.

And Europa doesn't have an atmosphere anyway, so that's correct.

Either way, if Hydrographics is supposed to indicate ice coverage, then every major moon in the outer solar system apart from Io (and probably the asteroidal moons) should be hydrographics A, because every major moon apart from Io has an icy surface.

Hence, I'm more inclined to believe that it is supposed to talk about liquid coverage. You're right in that it includes ice coverage on mostly liquid worlds too though. Which makes it somewhat confusing.

Maybe a combination of hyd A and Ic would serve to indicate that a moon has an icy surface. I guess one would just have to say that any non-asteroidal moon in the Outer Zone automatically has hydrographics A?

 

[Malenfant]

I'd heard that Mars was listed as atm 3 because it had been a bit terraformed. Dunno if that's canonical or not, but there you go.

But technically, Mars as it is today should actually be atmosphere 0. "Trace" isn't actually very "trace" at all, since wherever I've seen pressures listed for atmospheres in later Trav products, Trace has been shown as 0.01 to 0.1 bars. Mars, on the other hand, has an atmosphere of about 0.006 bars (6 millibars, tops), which is less than the lowest possible for Trace. Triton would also be listed as atm 0, since its atmospheric pressure is only a few microbars.

And Europa doesn't have an atmosphere anyway, so that's correct.

Either way, if Hydrographics is supposed to indicate ice coverage, then every major moon in the outer solar system apart from Io (and probably the asteroidal moons) should be hydrographics A, because every major moon apart from Io has an icy surface.

Hence, I'm more inclined to believe that it is supposed to talk about liquid coverage. You're right in that it includes ice coverage on mostly liquid worlds too though. Which makes it somewhat confusing.

Maybe a combination of hyd A and Ic would serve to indicate that a moon has an icy surface. I guess one would just have to say that any non-asteroidal moon in the Outer Zone automatically has hydrographics A?

 

[aramis]

And when the CT stats for Europa were written (Bk6, IIRC), Voyager was the New Thing. We know a lot more as laymen now than most astronomers did at the time about the jovian moons.

and for mars, it's 6.9 to 9 mb, depending upon weather, at the Viking site, 4-8.7 at mean radius, according to nasa, and does have free O2... 0.13%

Still well below the 100 millibars required for Very Thin... but quite a range.

Nasa Datasheet for Mars

 

[aramis]

And when the CT stats for Europa were written (Bk6, IIRC), Voyager was the New Thing. We know a lot more as laymen now than most astronomers did at the time about the jovian moons.

and for mars, it's 6.9 to 9 mb, depending upon weather, at the Viking site, 4-8.7 at mean radius, according to nasa, and does have free O2... 0.13%

Still well below the 100 millibars required for Very Thin... but quite a range.

Nasa Datasheet for Mars

 

[Malenfant]

Originally posted by Aramis:
And when the CT stats for Europa were written (Bk6, IIRC), Voyager was the New Thing. We know a lot more as laymen now than most astronomers did at the time about the jovian moons.

Book 6 was 1983, right? The Voyager flybys of Jupiter were 1979, and the flybys of Saturn were 1981. And it was very apparent (even to laymen at the time) that the surfaces of all the moons images (other than Io and Titan) were icy. Though I note that it's Io that is listed as having a Trace atmosphere (again, that it doesn't have), not Europa.

and for mars, it's 6.9 to 9 mb, depending upon weather, at the Viking site, 4-8.7 at mean radius, according to nasa, and does have free O2... 0.13%

Still well below the 100 millibars required for Very Thin... but quite a range.

More to the point, the oxygen pressure there is miniscule. And it's still below the 10 millibars required for "Trace".

 

[Malenfant]

Originally posted by Aramis:
And when the CT stats for Europa were written (Bk6, IIRC), Voyager was the New Thing. We know a lot more as laymen now than most astronomers did at the time about the jovian moons.

Book 6 was 1983, right? The Voyager flybys of Jupiter were 1979, and the flybys of Saturn were 1981. And it was very apparent (even to laymen at the time) that the surfaces of all the moons images (other than Io and Titan) were icy. Though I note that it's Io that is listed as having a Trace atmosphere (again, that it doesn't have), not Europa.

and for mars, it's 6.9 to 9 mb, depending upon weather, at the Viking site, 4-8.7 at mean radius, according to nasa, and does have free O2... 0.13%

Still well below the 100 millibars required for Very Thin... but quite a range.

More to the point, the oxygen pressure there is miniscule. And it's still below the 10 millibars required for "Trace".

 

[daryen]

Originally posted by Malenfant:
Either way, if Hydrographics is supposed to indicate ice coverage, then every major moon in the outer solar system apart from Io (and probably the asteroidal moons) should be hydrographics A, because every major moon apart from Io has an icy surface.

I'm inclined to believe it was a mistake in Book 6. (Sorry for my mistake on Europa. I misremembered which moon had the atmosphere.)

Again, if you take out the ice caps, then Terra should not be hydro 7. Most of the descriptions I have read of the various canonical worlds (e.g. Nosea, which I mentioned before) include any ice caps (if present) within the hydrographic percentage.

Another example: Mithril. It has a hydrographic percentage of 8, but much of the water is under ice. If the ice was removed, its hydrographic number would be much less than 8.

Yes, this means that planets without an atmosphere of 3-9 are screwy. But then, we already knew that.

 

[daryen]

Originally posted by Malenfant:
Either way, if Hydrographics is supposed to indicate ice coverage, then every major moon in the outer solar system apart from Io (and probably the asteroidal moons) should be hydrographics A, because every major moon apart from Io has an icy surface.

I'm inclined to believe it was a mistake in Book 6. (Sorry for my mistake on Europa. I misremembered which moon had the atmosphere.)

Again, if you take out the ice caps, then Terra should not be hydro 7. Most of the descriptions I have read of the various canonical worlds (e.g. Nosea, which I mentioned before) include any ice caps (if present) within the hydrographic percentage.

Another example: Mithril. It has a hydrographic percentage of 8, but much of the water is under ice. If the ice was removed, its hydrographic number would be much less than 8.

Yes, this means that planets without an atmosphere of 3-9 are screwy. But then, we already knew that.

 

[Malenfant]

Excuse me while I suppress the urge to tear CT books 3 and 6 apart with my teeth and hurl their remains onto a bonfire that I gleefully dance around...

Ahem.

OK, what have we got here...

a) Hydrographics is percentage of planetary surface covered by [liquid] seas or oceans (book 3, pg 7).

b) worlds with vacuum atmospheres with hydrographics will be icecapped - no free-standing liquid will be present (book 3 pg 8 and 16, book 6 pg 32). Atm 0 or 1, hyd 1+.

That's all we have in the core rules for CT.


Now, it would seem that this is in practise interpreted to mean that:

a) Worlds with atms 2+ and hyd 1+ are never labelled as Ic, even if they're mostly covered with ice.

and as a corollary

b) For worlds with atms 2+ and hyd 1+, the hyd digit indicates how much liquid is on the surface, and it doesn't matter if this happens to be mostly under a lot of ice.

c) The assumption seems to be that for worlds with atm 0 or 1, the surface is rocky and any hydrographics will be ice on top of the rock (hence, "ice-capped"). But there seems to be no consideration for worlds with a surface made of ice - it seems that these are assumed to be hyd 0, because no liquid is exposed on the surface. Even if a world ocean lurks under the ice, it's still treated as hyd 0. Perhaps these should be listed as hyd A and Ic?

 

[Malenfant]

Excuse me while I suppress the urge to tear CT books 3 and 6 apart with my teeth and hurl their remains onto a bonfire that I gleefully dance around...

Ahem.

OK, what have we got here...

a) Hydrographics is percentage of planetary surface covered by [liquid] seas or oceans (book 3, pg 7).

b) worlds with vacuum atmospheres with hydrographics will be icecapped - no free-standing liquid will be present (book 3 pg 8 and 16, book 6 pg 32). Atm 0 or 1, hyd 1+.

That's all we have in the core rules for CT.


Now, it would seem that this is in practise interpreted to mean that:

a) Worlds with atms 2+ and hyd 1+ are never labelled as Ic, even if they're mostly covered with ice.

and as a corollary

b) For worlds with atms 2+ and hyd 1+, the hyd digit indicates how much liquid is on the surface, and it doesn't matter if this happens to be mostly under a lot of ice.

c) The assumption seems to be that for worlds with atm 0 or 1, the surface is rocky and any hydrographics will be ice on top of the rock (hence, "ice-capped"). But there seems to be no consideration for worlds with a surface made of ice - it seems that these are assumed to be hyd 0, because no liquid is exposed on the surface. Even if a world ocean lurks under the ice, it's still treated as hyd 0. Perhaps these should be listed as hyd A and Ic?

 

[daryen]

I agree with those conclusions.

If a atm 0 or 1 world is covered with ice, but has liquid beneath the ice, it should probably be given hyd A (or whatever percentage) instead of hyd 0, and Ic. (Europa is like this, right?)

I also agree with your observation that Traveller assumes that all of its worlds are rocky. There is no allowance for any other type of world structure.

 

[daryen]

I agree with those conclusions.

If a atm 0 or 1 world is covered with ice, but has liquid beneath the ice, it should probably be given hyd A (or whatever percentage) instead of hyd 0, and Ic. (Europa is like this, right?)

I also agree with your observation that Traveller assumes that all of its worlds are rocky. There is no allowance for any other type of world structure.

 

[Malenfant]

Originally posted by daryen:
[QB]If a atm 0 or 1 world is covered with ice, but has liquid beneath the ice, it should probably be given hyd A (or whatever percentage) instead of hyd 0, and Ic. (Europa is like this, right?)

Yes. The problem is that it's kinda hard to tell which worlds have oceans under the ice and which ones don't. I would assume that any low density (rocky or icy) world in the outer system that is size 2+ has an ocean under the ice, and that some worlds that are size 1 do too (that seems to be the case in our solar system). Plus, even if they have oceans under the ice, it's not exactly relevant if they're inaccessible.

 

[Malenfant]

Originally posted by daryen:
[QB]If a atm 0 or 1 world is covered with ice, but has liquid beneath the ice, it should probably be given hyd A (or whatever percentage) instead of hyd 0, and Ic. (Europa is like this, right?)

Yes. The problem is that it's kinda hard to tell which worlds have oceans under the ice and which ones don't. I would assume that any low density (rocky or icy) world in the outer system that is size 2+ has an ocean under the ice, and that some worlds that are size 1 do too (that seems to be the case in our solar system). Plus, even if they have oceans under the ice, it's not exactly relevant if they're inaccessible.

 

[aramis]

And until the later ( ongoing dissemination) times, and the scientific community actually pausing to THINK about the HUGE collection of data, the knowledge base was growing near-exponentially through the mid 1980's.

We know now, but had no way of knowing then, that yes, superjovian and jovian worlds exist AND can orbit even inside the ecospheres... something which Bk6 allowed (tho' discouraged), and was oft scoffed at. Until the post-2000 wave of extra-solar planet discovery.

And, there was much speculation, as late as 1990, about Europa having an ocean. The photos were indicative, but not clear enough for most to say yea or nay firmly. The post-2000 wave of explorations has provided yet another crop, and has made some very strong implications that certain jovian worlds have liquid layers beneath the surface. Still, not proof of an ocean.

Considering the schedules which GDW operated under at the time, and the lack of readily available planetographic data at the time ( I was always searching for new data back then... most of the books out in 1983 were NOT including the V2 Saturn encounter, and many did not include the V1 nor V2 Jupiter encounter. In general, publication lacked 2-5 years behind the science for texts, and 2-8 years behind for popular press. I doubt strenuously that GDW staffers had time to actually compare their model to the new data....

As for Mars: Yes, lots of photos came out in the late 70's... but the planetographic data was not so public.

Modern astronomy has benefitted from the internet in both exposure (web sites have far more public access and far easier finding than the fairly limited materials available in even the modern popular press, let alone scholarly written works), and peer review.

The current extra solar discoveries threaten to invalidate nearly every Sci-Fi RPG's system building. That the model is so well done as to have only minor (and explainable by human activity in the setting in one case) issues is a good thing, and a sign of quality.

 

[aramis]

And until the later ( ongoing dissemination) times, and the scientific community actually pausing to THINK about the HUGE collection of data, the knowledge base was growing near-exponentially through the mid 1980's.

We know now, but had no way of knowing then, that yes, superjovian and jovian worlds exist AND can orbit even inside the ecospheres... something which Bk6 allowed (tho' discouraged), and was oft scoffed at. Until the post-2000 wave of extra-solar planet discovery.

And, there was much speculation, as late as 1990, about Europa having an ocean. The photos were indicative, but not clear enough for most to say yea or nay firmly. The post-2000 wave of explorations has provided yet another crop, and has made some very strong implications that certain jovian worlds have liquid layers beneath the surface. Still, not proof of an ocean.

Considering the schedules which GDW operated under at the time, and the lack of readily available planetographic data at the time ( I was always searching for new data back then... most of the books out in 1983 were NOT including the V2 Saturn encounter, and many did not include the V1 nor V2 Jupiter encounter. In general, publication lacked 2-5 years behind the science for texts, and 2-8 years behind for popular press. I doubt strenuously that GDW staffers had time to actually compare their model to the new data....

As for Mars: Yes, lots of photos came out in the late 70's... but the planetographic data was not so public.

Modern astronomy has benefitted from the internet in both exposure (web sites have far more public access and far easier finding than the fairly limited materials available in even the modern popular press, let alone scholarly written works), and peer review.

The current extra solar discoveries threaten to invalidate nearly every Sci-Fi RPG's system building. That the model is so well done as to have only minor (and explainable by human activity in the setting in one case) issues is a good thing, and a sign of quality.

 

[Malenfant]

Originally posted by Aramis:
Still, not proof of an ocean.

Europa has a magnetic field that can only be induced in a near-surface, electrically conducting layer by Jupiter's magnetic field. That's proof of an ocean, because that's the only thing that near-surface conducting layer could be.

Considering the schedules which GDW operated under at the time, and the lack of readily available planetographic data at the time ( I was always searching for new data back then... most of the books out in 1983 were NOT including the V2 Saturn encounter, and many did not include the V1 nor V2 Jupiter encounter.

I doubt that "many did not include the V1 or V2 Jupiter encounter" in 1983. That was 4 years earlier, plenty of time for something to be published. I've got a book from 1983 that has details of the Jupiter and Saturn encounters.

I doubt strenuously that GDW staffers had time to actually compare their model to the new data...

They were basing it on something. As it stands, the only things wrong with the solar system data in book 6 is that Io and Triton have a trace atmosphere when they should have none, and Mars has a Very Thin atmosphere (but that's supposedly from terraforming).

The "moons with oceans under ice" thing (which obviously GDW wouldn't have known about back then) is only a problem if if you assume that those moons should have hyd A. Personally, I don't think they should really - they should have hyd 0.

For that matter, Ic worlds with atm 0 or 1 with any hydrographic percentage are damn strange. You don't just get ice forming out of nowhere like that, if there's 10%+ of coverage then it had to have been in the form of large bodies of water at one point, which is rather unlikely unless all of these worlds somehow lost previously thick atmospheres. So perhaps the solution would be to say that worlds with atm 0 or 1 just can't have any hydrographics at all, thus removing the Ic classification (and the problem) altogether.

The current extra solar discoveries threaten to invalidate nearly every Sci-Fi RPG's system building.

I'd be less charitable about that - it DOES invalidate nearly every scifi RPG's system building. This is one reason that I'm trying to come up with a more up to date UWP system that can handle the things we know about today.

That the model is so well done as to have only minor (and explainable by human activity in the setting in one case) issues is a good thing, and a sign of quality.

Actually, it's a sign that they simply used what was known at the time, and that aspect just hasn't changed much since then. We know a lot more details about the solar system now than we did then, but the basic data that is listed in the physical UWPs have been known reasonably accurately since the late 70s.

 

[Malenfant]

Originally posted by Aramis:
Still, not proof of an ocean.

Europa has a magnetic field that can only be induced in a near-surface, electrically conducting layer by Jupiter's magnetic field. That's proof of an ocean, because that's the only thing that near-surface conducting layer could be.

Considering the schedules which GDW operated under at the time, and the lack of readily available planetographic data at the time ( I was always searching for new data back then... most of the books out in 1983 were NOT including the V2 Saturn encounter, and many did not include the V1 nor V2 Jupiter encounter.

I doubt that "many did not include the V1 or V2 Jupiter encounter" in 1983. That was 4 years earlier, plenty of time for something to be published. I've got a book from 1983 that has details of the Jupiter and Saturn encounters.

I doubt strenuously that GDW staffers had time to actually compare their model to the new data...

They were basing it on something. As it stands, the only things wrong with the solar system data in book 6 is that Io and Triton have a trace atmosphere when they should have none, and Mars has a Very Thin atmosphere (but that's supposedly from terraforming).

The "moons with oceans under ice" thing (which obviously GDW wouldn't have known about back then) is only a problem if if you assume that those moons should have hyd A. Personally, I don't think they should really - they should have hyd 0.

For that matter, Ic worlds with atm 0 or 1 with any hydrographic percentage are damn strange. You don't just get ice forming out of nowhere like that, if there's 10%+ of coverage then it had to have been in the form of large bodies of water at one point, which is rather unlikely unless all of these worlds somehow lost previously thick atmospheres. So perhaps the solution would be to say that worlds with atm 0 or 1 just can't have any hydrographics at all, thus removing the Ic classification (and the problem) altogether.

The current extra solar discoveries threaten to invalidate nearly every Sci-Fi RPG's system building.

I'd be less charitable about that - it DOES invalidate nearly every scifi RPG's system building. This is one reason that I'm trying to come up with a more up to date UWP system that can handle the things we know about today.

That the model is so well done as to have only minor (and explainable by human activity in the setting in one case) issues is a good thing, and a sign of quality.

Actually, it's a sign that they simply used what was known at the time, and that aspect just hasn't changed much since then. We know a lot more details about the solar system now than we did then, but the basic data that is listed in the physical UWPs have been known reasonably accurately since the late 70s.

 

[aramis]

Mars has a clear Ic earned, at it's No Atmosphere, according to you, Mal. (where is the 0.01-0.1 bar definition, anyway?) Given the profound effects of Mars' atmosphere, and the plans to put flying probes there, I'd say clearly that limiting trace to 10mb is moronic with a capital stoopid... but that's just me. I'd put the limit at 1 mb mean radius median pressure...)

The Martian Ice caps are, in fact a mix of CO2, Water, and other things, but they ARE there, and do have a growth shrinking cycle. (and the H2o is a minor component...)

As for books from the early 1980's, I recieved a dozen popular astronomy texts which didn't incorporate any of the V2 encounters; over half of them didn't incorporate all the V1 knowledge. (One, which was new in 1982, only listed 9 jovian moons... I remember being upset that it didn't include new data). It was, for me, a very disappointing year.

Now, any one who isn't including last years space probe data is scientifically in trouble. In 1982, (which, for a 1983 print date, is the reasonable cutoff) not being current within the last 5 years was not uncommon in MANY disciplines. Add to that the problems of dissemination via fairly narrow channels with some very interesting criteria for publication... Television was about the best source for astronomy in the early 1980's...

Cosmos (which did include the V1 and V2 Jupiter encounters) was the true turning point amongst those I associate with... it was taking and making space science understandable to upper elementary kids, and the companion book was cutting edge.

Most books on space were either texts for scholastic use (HS/College), or were aimed at juveniles. And most of the latter were, well, well out of date.

Heck, A school I often work at just recently bought a book on space, 2003 imprint, which doesn't mention Jupiter's Rings, and lists only half as many moons for Jupiter and Saturn as are on the nasa pages!

Now, if we look at Bk6, it doesn't prevent LGG's from being in the inner system. (It does discourage it, but doesn't preclude it.) Sure, it lacks the superjovians (which, many thought, were essentially impossible without ignition until recently). Superjovian used to be though to limit about 5-10 joves in mass. Now, we know they can be bigger than that...

Back to topic... Ic makes perfect sense, if, as you propose, mars is listed as Atm 0. I'd say it would make little sense in the inner zone, but in the outer zone, it makes a lot of sense (but does imply a lot of Ic worlds are actually martian-like).

 

[aramis]

Mars has a clear Ic earned, at it's No Atmosphere, according to you, Mal. (where is the 0.01-0.1 bar definition, anyway?) Given the profound effects of Mars' atmosphere, and the plans to put flying probes there, I'd say clearly that limiting trace to 10mb is moronic with a capital stoopid... but that's just me. I'd put the limit at 1 mb mean radius median pressure...)

The Martian Ice caps are, in fact a mix of CO2, Water, and other things, but they ARE there, and do have a growth shrinking cycle. (and the H2o is a minor component...)

As for books from the early 1980's, I recieved a dozen popular astronomy texts which didn't incorporate any of the V2 encounters; over half of them didn't incorporate all the V1 knowledge. (One, which was new in 1982, only listed 9 jovian moons... I remember being upset that it didn't include new data). It was, for me, a very disappointing year.

Now, any one who isn't including last years space probe data is scientifically in trouble. In 1982, (which, for a 1983 print date, is the reasonable cutoff) not being current within the last 5 years was not uncommon in MANY disciplines. Add to that the problems of dissemination via fairly narrow channels with some very interesting criteria for publication... Television was about the best source for astronomy in the early 1980's...

Cosmos (which did include the V1 and V2 Jupiter encounters) was the true turning point amongst those I associate with... it was taking and making space science understandable to upper elementary kids, and the companion book was cutting edge.

Most books on space were either texts for scholastic use (HS/College), or were aimed at juveniles. And most of the latter were, well, well out of date.

Heck, A school I often work at just recently bought a book on space, 2003 imprint, which doesn't mention Jupiter's Rings, and lists only half as many moons for Jupiter and Saturn as are on the nasa pages!

Now, if we look at Bk6, it doesn't prevent LGG's from being in the inner system. (It does discourage it, but doesn't preclude it.) Sure, it lacks the superjovians (which, many thought, were essentially impossible without ignition until recently). Superjovian used to be though to limit about 5-10 joves in mass. Now, we know they can be bigger than that...

Back to topic... Ic makes perfect sense, if, as you propose, mars is listed as Atm 0. I'd say it would make little sense in the inner zone, but in the outer zone, it makes a lot of sense (but does imply a lot of Ic worlds are actually martian-like).