The Athasian Solar System

 

I’ve been meaning to write this article for some time, but needed to detail out a few things prior to publishing it. On occasion the question comes up asking what we know about the Athasian solar system.  Some have speculated that there are no other planets in the system, or that there were other planets but they were consumed by the sun when it underwent its transformation. Others speculate it is a full system with a fair number of planets and moons. 

Over the years I’ve collect the various pieces of info in the various sources.  What I found was there is very little information. However, some inferences must be made to detail anything out and 2e has the best sources for doing that.  Let's start with what we do know about.  We know the following:

Sun - the sun - sure it's a problematic sun and changes colors as the inhabitants of Athas muck with it, but it's the only one they got.

Athas - home.  The planet that everything happens on. Well, almost. It's somewhat earth-like, has life, has gone thru phases. Right now its very desert-like. It has two moons.

Guthay - the bigger moon (don't go 4e on me… It is bigger.) (Source.)

Ral - the smaller moon (again, don't go all 4e on me... It is smaller) (Source.)

The Messenger - a comet that appears every 45 years.. It's bright when it appears too.

That's all that really gets any attention other than other planes and whatnot. What else is in the night sky?  Well you have the constellations. All 12 of them. And the three cusps.

Balimarash the Caravan
Fiddle the Beetle
Hesper the Kenku
Saurus the Lizard
Cusp 1
Hortle the Spider
Sylk the Wyrm
Tasker the Scorpion
Pyrus the Wheel
Cusp 2
The Dragon
Tyrospur the Lion
Scratch the Basilisk
Krawler the Kank
Cusp 3

 But those aren't really the planets and not part of the "solar system" Are they? Just the stars in the background, but they are important and play a role. I explain more below.

There are two other signs in the cosmos that aren't readily apparent to most. Those are the Endlean cycle and the Seofean cylce. The 2nd Edition Revised DS Box Set has the following:

 "In the Calendar of Kings, years are counted off using a pair of concurrently running cycles: one of eleven parts, the other of seven. The eleven-part, or endlean cycle, is counted and spoken first, in the order presented above. The seven-part, or seofean cycle, is counted and spoken second. The endlean cycle is complete when Athas’s two moons, Ral and Guthay, meet in the heavens, resulting in a major eclipse that occurs every 11 years. The seofean cycle is more abstract, occurring after Agitation has led back to Fury in the cosmos."

When it comes to other planets, this was one place I looked. The first idea that comes to mind here was to just make two different planets: one with a 7 year period, let's call it "Seofea", and the other with an 11 year period, let's call it "Endlea".  This was touched upon years ago by Agantyr in his readme file of his merchant calendar program. (Source)  His comment there for the Seofean cycle was the following:

 "The first is the "Other Planet" theory.  This would be a large, possible gas giant with an orbital period around the dark sun of 7 years.  (Jupiter has an orbital period of around 12 years, so this is not unreasonable.)  This planet would pass through the same constellations in a 7-year cycle (as viewed from Athas).  The only problem with this theory is that there are already 12 constellations that are associated with the months.  For the planet theory to really be solid, the names in the Seofean cycle would have to correspond to 7 constellations."

 This relates to the idea that our own zodiac was created by watching Jupiter with is 11.86 year orbital period.  Think about where the stars are that are behind Jupiter or next to it at the start of each year.  Jupiter travels along the ecliptic and takes a full year to go through about one of our twelve constellations. Thus, we get twelve of them as it makes a complete cycle to get back to the stars it started on. Fine.

 But what if you do have a planet that takes 7 years to get around the sun? Do you then get seven constellations? Well, not necessarily. If Athasians are using that planet to help keep time and they want to name the seven cycles, the inhabitants can simply just give names to the stars that the planet is near at the start of each year.  So you give the brighter stars names where ever Seofea is on days of significance. i.e. the first day of the year.  Any name will do.  It just so happens that perhaps they chose: Fury, Contemplation, Vengeance, Slumber, Defiance, Reverence, and Agitation for some of the names of these brighter stars along the ecliptic.  Which is what I decided to do on my star map. These would be spaced out approximately 51.4 degrees apart.  Having a constellation that covers 51.5 degrees is a lot more difficult to deal with than one that is only 30 degrees.  Really Athasian constellations cover about 28.8 degrees each, if you account for the three "cusps". So perhaps Athasians just decided to divide the heavens into something more manageable, or perhaps the natural "break" in the stars and constellations “the cusps” helped to do this for them.

 

The other theory I have for the 12 constellations is that they are based on the moon cycle. I refers back to their orbital periods. (Source). The cusps would correspond to days when Guthay approaches being full in the sky. The twelve divisions could be due to Ral’s sidereal period of 30.33. In 375 days, Ral will pass through the entire zodiac 12.36 times. So 12 could be a natural division for the zodiac. When Ral completes each cycle a new constellation starts to rise and an old one sets.

Trying to name the phases of the Endlean cycle after stars is a little more difficult.  The 12 "Earth" constellations of the zodiac mentioned above were possibly created by a planet (Jupiter) with a twelve year cycle.  This idea versus the idea of having a planet with an eleven year cycle doesn’t translate as easily.  Of course you still could have a planet with an 11 year cycle, and I like this idea, but with cycle names already like "Ral" and "Guthay" it doesn't fit with the idea of naming these cycles for stars. The names of the Endlean cycle are a mix of elements, moons, people, centered about the "Dragon".  But the names may have referred to other events in the cosmos or event on Athas. My suggestion here is to still have a planet named "Endlea" but just have the reason for the naming of its eleven cycles lost to time; similar to the way the Heavenly Stems from of the Chinese calendar's sexagenary cycles have some ambiguity in their origins. However, it has been proposed there that the Chinese names of the Heavenly Stems refer to asterisms along the ecliptic that the moon passes. (Source).  This could be the case on Athas as well. 

Moving on from the Endlean and Seofean cycles, there is scant other references in the books.  There are references in 2e to psionic powers with ranges described as "interplanetary" (DS 2e Revised, Dragon Kings, Will and the Way) If Athas is a lone planet in the solar system, why bother having spells that have an interplanetary range?  Or why bother having this detail if interplanetary ranges are never meant to be attempted.

The best source outside of any of the core rulebooks for planets comes from the adventure "Marauders of Nibenay." There, the PCs enter the Fortress of Nibenay and enter one of the rooms that contains a giant orrery.  The description for the DM to read to the players says the following:

"This room, fully 100 feet wide and 150 feet long, is completely given over to one of the most amazing machines you have ever seen. The heart of the device is a large, spherical clockwork mechanism that contains thousands of delicate looking gears, wheels, and spings, all moving with what appears to be absolute precision. A dozen slender rods jut out from the massive central sphere, each ending in an assembly of globes that appear to move in circles, about each other and then (as a group) about the mechanism itself. Exits can be found on the north and west walls, but the convolutions of the machine make moving from one door to the other a very difficult task."

It then goes on to provide the following detail to the DM:

"This device is an orrery, a mechanical representation of the Athasian solar system. Nibenay, like many of his subjects, has a keen interest in astrology and has built this machine to help him his studies of the stars and the portents they bring. Any character who makes an Astrology check should be able to deduce the function of the machine and understand its value as an aid to astrological studies"

Voila! A description of the "Athasian solar system."   A careful reading of the text will also indicate that up to possibly twelve planets/bodies exist.  "A dozen slender rods" - (each potentially representing a planetary system) "jut out from the massive central sphere" - (which would be the position of the sun) -  "each ending in an assembly of globes" - (a planetary system)

 

The accompanying picture has a bit to be desired as far as orreries are concerned.  It is not presented in the conventional format of orreries as it lacks an obvious central globe for the sun that is seen in typical orreries, but it is the best we have and we can still infer some things. (Although it did occur to me that the orrery could be a geocentric model and not heliocentric model, thus moving the sun from the center.)

Although this is only one side of the orrery in the image, I decided to take it and group planetary bodies by what I could tell was an assembly of globes, and produced the following image:

 

I labeled these clockwise to assist referring to them. While I get 8 separate groupings here there are a total of 20 visible planetary bodies.  I list them as follows with some speculation:

 

1. 1 gas giant planet 6 moons  -This appears to be a large moon, possibly a gas giant with several moons.
2. 1 gas giant planet - This appears to be another large planet a gas giant with rings - no moons (or none discovered)
3. 1 planet 2 moons  - this fits the bill for Athas.
4. 1 planet - just a lone planet out there
5. 1 gas giant planet 4 moons - I'm going to go with a large gas giant, but with two bodies off the page makes it difficult to know.
6. 1 planet - another lone planet chilling out here.
7. 1 gas giant planet -  yet another lone planet.
8. 1 planet - another small one… maybe we just say this is the Messenger since we still need to account for it.

That means there would still be four other unaccounted for planetary systems (based on the 12 rods = 12 planets assumption) and it consists of at least four gas giants and 4 rocky planets. (Maybe you decide something a little different.)

Now we're cooking.  But what is the order?  There has been some parallels of Mars to Athas and inference over the years that Athas is in the same position as Mars or the fourth planet.  (Source.) People like to compare Athas to Mars. (John Carter) But it doesn't jive with the orbit of Athas (375 days) vs orbit of Mars (687 days). Also, I am opposed to a Mars-sized Athas (Source.), but I am ok with it being a fourth planet.  Here is my logic.

A while ago I stumbled upon an article that proposed there being an extra planet between Mercury and Venus at one time.  The premise involves some complicated equations that evaluate the harmonic resonances of known positions of planets to determine stable orbits of other potential planets.  It is used to predict additional exoplanets in other star systems.  And the method is pretty reliable. When the Harmonic Orbital Resonance Model is applied to our solar system the best fit adds the extra planet between Mercury and Venus and excludes Neptune. (Source.)  

If we allow the "Extra" planet, supposing it hasn't been "thrown out of the system yet" (see three body problem) and we keep Neptune by saying it "occupies a stable orbit between Uranus and Pluto, which does not match the primary progressive geometric pattern, but fits a secondary harmonic pattern." we end up with a decent list of planets.  And we then add an equivalent to Halley's Comet, the Messenger.

 I figure we put the order similar to our own system. For our own system we might get something like this (including dwarf-planets) - and that's twelve.  - of course you could add all the other objects beyond Pluto, but at least now I have 12 objects. (I've separated Halley's Comet since it is an oddball)

 

Planet	Days	Years
Mercury	88	0.240931
Extra	176	0.481862
Venus	225	0.616016
Earth	365.25	1
Mars	687	1.880903
Ceres	1682	4.605065
Jupiter	4331	11.85763
Saturn	10747	29.42368
Uranus	30687	84.01643
Neptune	60190	164.7912
Pluto	90560	247.9398
Haley	27394	75

 

Now we just plug in the equivalent or make some approximations.  I am taking some liberties with the exact days here to simplify things since this is a game. And these are not all orbits that conform with the Harmonic Orbital Resonance Model.- but at some point in your game you have to break physics and this is where I am breaking it.

 

	Planet	Type	Days	Athas Years
1	I	rocky	93.75	0.25
2	II	rocky	187.5	0.5
3	III	rocky	251.25	0.67
4	Athas	rocky	375	1
5	V	rocky	750	2
6	VI	rocky	1500	4
7	Seofea	gas giant	2625	7
8	Endlea	gas giant	4125	11
9	IX	gas giant	11250	30
10	X	gas giant	33750	90
11	XI	rocky	67500	180
12	Messenger	comet	16875	45

  

Now we just need some names for them… many languages over the millennia have used the names of deities for planets. Time keeping has also used names of deities and names of celestial objects for names of days of the week or names of months. But "Athas" = no gods, so I decided not to go that route.  Really the names of these planet could be a named anything, but I wanted to use Athasian names. So I looked to the names of the Athasian months to use as an analogue. I figured if the Athasians can come up with names for their months that aren't tied to deity then let's use those.  What I ended up with is the following:

 

	Planet	Type	Days	Athas Years	Moons
1	Macro	rocky	93.75	0.25	?
2	Morrow	rocky	187.5	0.5	?
3	Thauma	rocky	251.25	0.67	?
4	Athas	rocky	375	1	2
5	Alia	rocky	750	2	?
6	Ameron	rocky	1500	4	?
7	Seofea	gas giant	2625	7	6
8	Endlea	gas giant	4125	11	4
9	Anabas	gas giant	11250	30	?
10	Hoard	gas giant	33750	90	?
11	Flagst	rocky	67500	180	?
12	Messenger	comet	16875	45	0

 

So there is my list.  I know, I used some liberties there, but that's the best that I can come up with for now.  Most Athasians are probably only aware of the first 8 or 9 of these planets and the Messenger.  Since the last ones are so far away would be hard to see and move across the sky very slowly.

The one last thing I wanted to address somewhat what is on each planet… largely I think this is up to the DM to decide. And I would hope they are all mostly dead planets and moons… but maybe your campaign needs Guthay to be full of silk wyrms or Flagst full of frozen undead.  But I don’t think any are teeming with normal "life".  I think this takes away from the desperateness of Dark Sun.  But how you decide to play in Dark Sun is totally up to you.  But above are just some ideas.

Enjoy.

-Rovewin