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A Guide to Mystaraspace

by Francesco Defferrari from Threshold Magazine issue 15

Through the reports of daring explorers!

The Worlds beyond Mystara

by Marcus Ieros Tirallos, University of Thyatis

Some wizards and sages say there are many other worlds around Mystara. The infamous Alphatian pirate Haldemar of Haaken described his visit to the supposed invisible moon, Patera, which was inhabited by rakasta and other animal beings. The Traladaran adventuress Claransa recently described the Hollow World beneath our very feet. Even the more well known moon of Matera is Hollow, with whole civilizations inside it!
I am not at this stage able to judge if such claims are true or not, but I have heard elven tales about the “seven worlds” which are a part of Mystara.
The first one would be the surface world we all know, vast as it may be.
The second one would be the world under the seas, inhabited by aquatic creatures.
The third one would be the world in the skies, above the clouds, inhabited by cloud giants, fairies and all manner of flying creatures.
The fourth one would be the world under our feet, the dark underground called Shadowdeep by the Shadow elves.
The fifth one would be the Hollow World.
The sixth one would be the invisible moon of Patera.
The seventh one the visible moon of Matera and its interior.
From this list it’s easy to understand that Mystara alone has more worlds than anyone will be able to explore in just a lifetime, but beyond Mystara there are many others, probably infinite, worlds.
There are obviously the other planes of existence well known by magical studies. The Ethereal Plane, the Astral Plane, the Elemental Planes, the Outer Planes of the Immortals. Some sages also say that our Prime Plane and all these other Planes are just one dimension of the many that compose the Multiverse.
All this could be quite disorienting for anyone, but the purpose of this article is not to explore the seven “worlds” of Mystara nor the many worlds of the Planes, but “only” the other planets which rotate in the sky beside the planet Mystara.
Indeed sages have discovered that Mystara is a planet which orbits around the sun, with its two moons that likewise orbit it. Some also say the planet is a living being, but a discussion about this is beyond the scope of this article1.
Our purpose here is to discuss the existence and the characteristic of other planets beyond Mystara, i.e. other celestial bodies which, like Mystara, orbit around the same sun.
We will see we have many reports on such celestial bodies, often conflicting with one another. The reader will judge which report he or she judges more trustworthy.

[Sidebar: Races of the Multiverse]

Obviously, all the D&D campaign worlds share the same basic races, generally humans, elves, dwarves, halflings, gnomes, humanoids, giants and dragons, and more. The same races appear in many other fantasy books, movies and worlds and were mostly introduced in the genre as we know it now by the works of J.R.R. Tolkien. Despite the fact that the D&D worlds were connected by Spelljammer, through the Prime Plane Universe, and by Planescape, through the Planes, D&D never bothered to establish a common origin for the different races.
Moreso, often each campaign world has its own particular origin story for its races, incompatible with the stories of the other campaign settings. For example, in Mystara humanoids were supposedly created by the Immortal Hel just a few thousands of years ago, and in Dragonlance dwarves were supposedly gnomes mutated by the magic of the Graygem.
In order to use all the D&D campaign settings in the same universe, the DM could either assume a very strange case of parallel evolutions, or consider that all the local origin stories are false. This is not really so strange considering that on our Earth too, until a few centuries ago, the origin stories as presented in myths and religions were considered the truth, but now our modern understanding of the universe has disproven such stories or, at the very least, has forced religions to revise them or consider them only as symbolic narrations.
The same could be true for all the D&D campaign worlds or any other fantasy world the DM wishes to use in her or his campaign. In this case all the elves of the Multiverse must have an unique common origin, and the same goes for all the other races, including humans.
Either way, for a PC discovering that others of his/her race exist in the Multiverse should be quite a mind-shattering experience. A Mystaran dwarf discovering there are other, very similar dwarves on other planes and planets will either go into full denial (saying to himself/herself that “they must be descended from Mystaran dwarves, as we are surely the only original dwarves”) or accept that the Multiverse is much bigger and complicated than she/he thought, and grandmother’s story about dwarves being created by Kagyar from the stones of Mystara was not so truthful as she/he liked to think.
Obviously to begin a journey to discover the True Origin of the dwarves (or any other D&D race) could be a great adventure seed for any campaign set in the Multiverse.
The same is also true for the many non-intelligent monsters usually shared by different campaign settings.

Recent sources

Editor’s Note:
Obviously all the source authors are real people who posted their own descriptions of Mystaraspace previously on the Mystara Mailing List or the Piazza, and whose work is now stored in the Vaults of Pandius
Dating sources to the Mystaran calendar: see for example the first referenced source below by Joseph DuBois; as he originally posted it back in 1995, I have transformed the date into 995 AC in-world, as I have done for all the other sources.
This equating of authors to Mystaran characters and dating conversions are intended as a celebration of the work done by members of the Mystaran community in the last 20+ years. I think Mystaraspace and its planets are big enough to have enough space for all the ideas developed by the fans until now, and more.
- Sturm aka Francesco

First, I will list all the sources I have found so far relating to “Mystaraspace” (the name I will use for the solar system). This list may well be only a partial one. For all the research I have done I cannot obviously exclude that a more learned sage, or accomplished wizard, in Alphatia, Matera, Davania or any other place in Mystara knows much more than me of the planets of Mystaraspace, and yet his or her works may not be available in Thyatis, or in all the other places and nations where I found the below sources:
- Joseph DuBois, a mysterious wizard from Renardy or Glantri, published a small description (titled “Mystara Space” of some planets of Mystaraspace in 995 AC, indicating the existence of water wizards on the fourth planet. I suspect however he may have confused our system’s planets with those belonging to the ancient Alphatian solar system, which should be another one entirely and not the same solar system of Mystara.
- Daniel Boese, another sage of unknown origin, possibly Darokinian, who is famous as the author of other essays and a very detailed timeline of Mystara2, published published “Mystaran Solar System” giving some measurements of the planets of Mystaraspace back in 996 AC. The only planet he briefly described is Damocles, fourth from the sun, which contained an undescribed civilization. He probably had the same mysterious Blackmoorian source of Mishler, see below.
- The notorious sage James Mishler, also known as Mystaros, who has published extensive and appreciated works on many topics, wrote “Mystara solar system” in 996 AC, a short description of the solar system listing the planets as Valerias, Mystara, Ares, Damocles-Vanya, Viudan, Khoronus, Protius, Razud and Thanatos. Inhabitants of such worlds were also listed. I have reason to believe the number of planets is correct and goes back to ancient Blackmoorian sources (indeed some say Mystaros himself is an ancient Blackmoorian) compiled by a sage named Frank Mentzer3. The names of the planets however may not be correct, as we will see.
- A Thyatian general named Agathokles has published in AC 1001 an extensive account on the history of the planet Damocles, “History of the Grens & the Emerondians” that he learned from the inhabitants of the remote Davanian nation of Emerond. He may also have utilized a previous account, “Aliens In Mystaraspace” published in 999 AC by another Thyatian, Marco Dalmonte. [Also, see the article on this topic by Agathokles in this issue of Threshold]
- A Glantrian sage named Kit Navarro published also in 1001 AC a treatise “Arcana Mystara”, on Mystaran astrology and astronomy which also contains a description of the planets and the solar system.
- Another sage or explorer named Cab Davidson, supposedly another Darokinian, published a “Summary of the Mystaran Solar System” in 1005 AC describing all the planets.
- The Thyatian Giovanni Paniccia published another short description of the planets of the solar system titled “Mystaraspace” in 1006 AC.
- The Glantrian Charles Taylor wrote another account on the planets (“Mystaraspace” in 1008 AC and a further description (“Mystaraspace and Charon/Asterius” of the last planet, Charon, which he however calls Asterius, in 1009 AC. Taylor published yet another account (“Planets of Mystaraspace” in 1010 AC, leading me to think he could have really travelled the Mystaran solar system.
- A rather mysterious explorer or sage who just signs with the name Cab published an account titled “Planets of Mystaraspace” in 1009 AC. His description of the planets is the same as Davidson, so they may well be the same person. However, Cab added more detailed descriptions of the planets “Alphatia/Masauwu” and “Valerias”
- Also in 1009 AC, a sage from the Northern Reaches named Håvard published a description, “The Mystaran Solar System”, and a “Map of Mystara’s Solar System” in 1010 AC.
- In 1010 AC a mysterious sage, maybe a Glantrian, known only by the pseudonym of Ripvanwormer published an extensive description of the 7th planet, Tarastiae4. He later also did research about the names the planets had at the time of Blackmoor5.
- In 1016 AC a Darokinian sage who signs himself RobJN published an extensive account, “[Thornspace] TS1: Sarimaar, The Red Wanderer” on the 4th planet, Vaniae, which he calls Sarimaar6.
- More recently a Glantrian sage named Robin is trying to compile the available information on Mystara’s solar system, aided by others, such as Håvard and Ripvanwormer7.
- Finally a Thyatian named Stefano Leonardi has just published an extensive description of the second planet, which he calls Ishtar8

Some of these sources may be false, and certainly some may seem to contradict each other. Yet if we think how big a planet may be, such contradictions could be easily explained by the fact that different travellers landed in very different parts of the same planet. Just imagine a first explorer visiting the desert of Ylaruam, a second one visiting Thyatis city and a third one visiting the realms of the Undersea. The first one would leave a description about a desert planet, the second one would describe a planet full of wonderful cities, the third one a planet covered in waters and inhabited by undersea people. Yet they would have landed just a few hundreds of miles apart. Just imagine the same on an even larger scale. Therefore, even if we cannot exclude some of the information listed below as false, they may well be all true, as a planet is a very big place and few, if any, may be able to explore one completely.

I also have my very own source, a Thyatian rogue named Mario Ferrer, which claims to have visited the solar system with his own flying ship, investigating the truth of the reports of other explorers. As for all the other sources, I cannot guarantee that his claims are true, even if he added several details to the descriptions of the planets, as you can read below9.

More ancient and alien sources

Before the works done in recent years, previous sages and ancient civilizations wanted to explore the planets of Mystara’s solar system as well. I will describe here what I have learned so far about these ancient explorers. The Blackmoorian sage Frank Mentzer has already been mentioned above, and the work of the mysterious Darokinian sage who uses the name of Chimpman is also fundamental, as he described several former Mystaran cultures who now live in outer space10. He writes that several cultures of Mystara’s past, notably the saurian carnifex, the Blackmoorians and the Thothians11, were able to build flying ships and travel to other worlds. According to Chimpman these people now live mostly beyond Mystara’s solar system, but some can also be encountered among the nearby planets. Other cultures too apparently have travelled among the stars, such as Alphatians, aranea, elves, lizardmen and humanoids, for various reasons. He also adds brief descriptions of the planets of Mystaraspace, added below.
The Sheens are a race of intelligent constructs supposedly of Blackmoorian origin, described by Chimpman in his work12. They are not the only intelligent constructs known to roam outer space. The mysterious Oards, part humanoids and part machine, and the even more mysterious Meks13, have been spotted in Mystaraspace and on Mystara itself several times.
Then there are other alien races, which are believed to be both planar and space travellers, such as the strange illithids, and the more known beholders, adaptors, along with many others14. All the people mentioned above probably have detailed and extensive knowledge of the planets of Mystaraspace, but they have not shared such knowledge with us inhabitants of Mystara, at least as far as I know.
At the present status of my knowledge, I think there is no culture or nation in Mystaraspace which is organized enough or advanced enough in magic to have explored it fully. However it is possible that ancient Blackmoor was indeed so advanced to have done that. I have clues about Alphatians having small colonies on several planets, but apparently many of them are not in contact with their original empire anymore, either because they decided to leave it, or because they unwillingly lost any contact with it. The Heldannic Knights and the Myoshimans certainly have their flying vessels, and they may have explored parts of Mystaraspace, but both cultures are notoriously secretive about their knowledge, so the general public does not know anything about the extent of their knowledge.
Travelling through the great expanse of space is not easy, and few cultures have enough resources to do it, let alone maintain steady connections. However some culture or nation of Mystaraspace, maybe on a far away planet, could be advanced enough to explore the nearby worlds and maybe one day achieve contact with us.

The Solarios System, or Mystaraspace

The Sun - Solarios - Ixion

Circumference at the equator: 2,714,336 miles15
At the current state of our studies, no sage worth his or her reputation doubts anymore that the Sun, or Ixion or Solarios as it is often called, is the center of our solar system, the fulcrum around which several planets and other celestial bodies, such as comets, orbit.
Some say the Sun is the domain of the namesake Immortal, others it is just a huge portal to the Elemental Plane of Fire. Maybe both ideas could be true. It seems it has fire elemental inhabitants, but I have no reliable recounts of wizards ever visiting it.

Mario apparently did not dare to go near to the sun, so he has nothing to add about it.

Alphatia - Masauwu - Alphaksis - Asterius - Sin16
Supposed circumference at the equator: 9,520 miles17.
Kit Navarro and other sources mention this planet, while others deny it exists. A possible theory is that the planet was until recently an asteroid in the Asterius/Damocles belt which fell into another orbit during the Wrath of the Immortals. Some have named it Alphatia after the immortal, not the empire. According to Navarro the planet is bright as a diamond and has a rocky surface, inhabitants are not mentioned.
According to Davidson, it is a hot, almost molten planet, inhabited by efreets, fire elementals and other fire loving creatures. He also says that certain immortals of energy make bases there, but few travellers from Mystara visit this place, for obvious reasons.
Cab, which may be an alias of the above, expanded this description, writing that the planet as a curious day and night cycle of 59 Mystaran days. During the long “day” the planet is hot and fire creatures can thrive, while during the long “night” only ice loving creatures can survive. Therefore the fire and ice creatures migrate constantly, some of them on true moving cities pulled by gigantic beasts of burden, following the day or the night, not even fully aware of the existence of the other people. Cab also writes that the poles have deep craters, probably inhabited by entropic creatures, and that some ice people have built stable residences in the depths of the crust, where they can avoid the extreme heat of the long days.
Håvard names this planet just the First, Alphaksis in his map, and says it is the home of fire creatures and a stronghold of red and ruby dragons.
Robin names the planet Asterius, and says temperatures are extreme, and the atmosphere very thin.
Chimpman only describes this planet as a harsh, sparsely populated place.

Mario says this planet was originally in the orbit of Damocles, and only in the last years it came to be here. He says all the reports of previous explorers have some truth in it: there is a region of crystalline and icy terrain, where creatures who follow Alphatia have built great houses and castles of crystal, able to withstand the extreme temperatures. There is a region of hot desert, inhabited by creatures who follow Alphaks. And there are followers of Masauwu and Asterius who migrate all around the planet, to trade or, in some cases, pillage. And there are dragons and flying creatures. The planet is smaller than Mystara and has a lighter gravity, so visitors will feel lighter here and natives are often able to jump quite far. Valerias and Mystara are extremely bright from here and the natives have legends about them. The planet has many craters, as many asteroids hit it in the past, when it was in the same orbit of Damocles.

[Sidebar: Air, Diseases and Food (mostly by Robin)]

Three major dangers for explorers of an unknown planet are:
1) the composition of the "air", which may be breathable only to the locals (adapted or by magic), 2) the local micro organisms (diseases) and 3) food. Explorers may find impossible or difficult to breath or become sick in another environment due to lack of exposure from birth to certain bacteria. Secondly explorers could also be appalled by the shapes, taste, source, cooking, way of eating (or drinking) of the local food.
Spells such as "Air Breathing", "Protection from Disease", or "Adaptation" would be able to to prevent the first and the second danger, and these would surely be available to travellers (be it on scroll/device or spell), but a disease could also be subtle and slow enough to be very difficult to detect, or clerics could be unable to heal it fully. The third danger (food) however, must be overcome through trial and error as even a "Detect Poison" spell fixed to the caster's biology, could not reveal taste, way of preparation and other peculiarities. There are also poisonous plants which are very edible if rightfully prepared (for example Cassava, Acorn).
Some alien cultures could be used to eat specific rocks (or rock like plants), and be surprised to find non-edible rocks in other worlds, while vice versa human-like creatures could search for food and find nothing, not realizing they are standing on edible and alien rock like plants. The DM could also decide that a "Create Food" spell gives only the local edible foods, which could not be recognized as such by the PCs.

Valerias - Telax18 - Phellia19 - Ishtar

Circumference at the equator: 23,816 miles20.
Mystaros indicates saurial cultures here.
According to Navarro the planet has an atmosphere of poisonous gasses and only gemstone dragons live here.
According to Davidson the planet is covered by swirling clouds, has a mysterious history, and is inhabited by creatures such as spectral hounds, mujina, diaboli and other monsters of the dimension of nightmares.
Paniccia says only some sollux inhabit this hot planet, and some planar travellers occasionally visit it.
Taylor says this planet has a thick hot and acidic atmosphere, with permanent cloud cover. Most native animals are reptiles or dinosaurs, and black or onyx dragons are common. He also says the planet is Hollow, with small polar openings, and the insides would be a lot more temperate than the outside. In his later description, he says the polar openings appears as multi-mile wide whirlpools, and the outside is dominated by an alien race named the hurwaet, and by another race possibly related to the Mystaran carnifex. He adds that the inner world would be dominated by oceans, with dry land only on low-flying continents.
Cab describes Valerias as a hot world shrouded in clouds, where the day lasts for 117 Mystaran days but light is always scarce. Algae float in the upper atmosphere and the great forests are inhabited by diaboli, mujina and other nightmare dimension creatures, but also by gator men, cay men, lizard men and tortles, and whale like creatures in the seas. The planet is also frequently swept by massive vortex storms. Cab mentions also ancient abandoned pyramids on this planet.
Håvard names this planet the Second, Valeriae in his map, and says it is misty, humid, dominated by dinosaurs and lizardmen. He attributes the ancient pyramids mentioned by Cab to the ancient civilizations of the Azcan and Oltecs, who supposedly reached the planet before the Great Rain of Fire. He also confirms the planet is hollow as mentioned by Taylor.
According to Robin the lower atmosphere is made of carbon dioxide, but the upper has oxygen and floating life forms.
The elven name would mean “The one beyond”, as the planet is nearer to the sun than Mystara. I believe the elves have explored the solar system much more than they would like other nations to know, or are in contact with some spacefaring culture21.
Chimpman says this planet, overgrown with lush vegetation, could have been the original home of the carnifex, but now their once advanced magical civilization that spanned the whole planet has long disappeared.
A Thyatian explorer or sage named Stefano Leonardi is very recently describing this planet in detail22. He writes that the planet is inhabited by descendants of Blackmoorians colonists and their slaves.

According to Mario, the 117 Mystaran days long night on Valerias is brighter than the day: while during the day only pale red light reaches the surface, during the night the clouds emit strange green lights creating fantastic auroras, perhaps caused by the algae mentioned by Cab. The seasons instead last only about 2 months each, but its temperature is hot almost everywhere due to the thick atmosphere, and snow can be found only on the highest mountains. This planet also has many volcanoes and frequent earthquakes, and lightning storms. Atmospheric pressure is higher than on Mystara, so a visitor will feel slow and heavy on this planet, and the inhabitants tend to be stocky and strong. For the same reason, flying creatures are quite rare. Mario says Valerias is almost as big as Mystara and it is the home of many different people and cultures, including all the ones mentioned above by previous explorers. Curiously, the sun rises in the west and settles in the east.

[Sidebar: Days, Seasons, Gravity]

The length of days and seasons on the planets and moons of Mystaraspace could well be the first major cultural shock for visitors of an alien world. Mystaran would be very surprised by the long Valerian day, and Valerians would be likewise very unnerved by the quick and massive changes between day and night. Gravity and atmospheric pressure will also be an immediate shock for outsiders, as the inhabitants of moons and other planet will feel the pressure on Mystara, Valerias and in the atmospheres of the gas giants crushing and insufferable. Visitors coming from Mystara and Valerias will instead feel very light on Vaniae, Damocles and many asteroids and moons and the native inhabitants too will be capable of fantastic jumps. Some planets and moons, such as Valerias and the biggest moon of Khoronus, may have an atmosphere so thick it can be almost impossible to see the stars from their surface. All these variables will have huge societal and material impacts on the native inhabitants and cultures. In planets with very long days and nights, the inhabitants will have to sleep several times during the day, and the wake and sleep cycle will be quite different from that on Mystara. In planets with extreme seasons, the inhabitants will have to adapt to major changes, maybe living underground during the winter. In planets with low gravity but a normal atmosphere, flying and gliding could be quite convenient. On planets with low gravity but a rarefied atmosphere, jumping could be easier and even normal breathing could be a challenge. On planets with high gravity and a rarefied atmosphere flying may be impossible, while where both gravity and atmospheric pressure are high, only powerful or magical creatures may be able to fly.

Circumference at the equator: 24,900 miles23
Mystara and its Hollow World will not be detailed here, but only the information written by explorers and sages about its two satellites.
Matera, the visible moon, has an equatorial circumference of about 6,785 miles while Patera, the invisible one, has a circumference of just 2,900 miles.
Taylor says the interior of Matera would be inhabited by many insect-like creatures, including hivebroods.

Mario has not much to add on the moons on Mystara, as he says other explorers have already published extensive accounts on them.24

Vaniae - Ares - Rathanos - Sarimaar - Loth25 - Henrin or Zugzul26
Circumference at the equator: 13,195 miles27.
Vaniae has two very small moons with an equatorial circumference of less than 40 miles.
Each culture of Mystara has its own name for this planet.
Mystaros indicates unusual creatures and barbarian humans here.
According to Navarro the planet is subject to violent storms and has seasons of extreme heat and extreme cold, and is inhabited by frost and flame salamanders.
Davidson describes the planet as a harsh, cold desert world, and he names it Ixion not for its heat but for its intense red colour in the sky. He says it is a world where water is scarce, inhabited by earth creatures.
Paniccia confirms fire and frost salamanders as the main inhabitants with an alternate lethargic cycle, as described by Navarro. He also précises that Thyatians astronomers call it Vanya, because in winter it is cold and grey, while Ylari astronomers call it Rathanos, because in summer it is red and burning like the Lord of Flames.
Taylor says the planet is inhabited by four armed creatures which may be related to the sandfolk or ungolwaith of the Adri Varma plateau, and other strange monsters, but also by some humans. He later added that the northern hemisphere is filled with water, while the south is largely desert, with many canals.
Håvard says this Fourth Planet, Vaniae in his map, is a desert, and that is the original home of the sandfolk, who were brought to Mystara by the Blackmoorians. He also says that the ancient Thothians28 also colonized the planet and built canals and pyramids. Besides the sandfolk, other native inhabitants would be insect men, earth creatures and brown dragons. He also says this planet is hollow too, but does not specify if its hollow world is inhabited.
A big asteroid named the Crown Rock passes near its orbit according to Håvard’s map.
According to Robin, the two small moons may be artificial satellites built by an unknown civilization. The planet’s ancient civilization would be in decline or disappeared entirely, and the atmosphere thinning.
According to RobJN, the planet would be called Sarimaar by the natives, who would be sandfolk and ancient Blackmoorian colonists. The planet’s environment is unforgiving to humans, with extreme cold, even in the local summer. Supposedly the planet skyshield was heavily damaged before the Great Rain of Fire.
Chimpman says it looks like a cold, icy and dead world, due to a catastrophe which hit it. He however writes that some ancient inhabitants are hidden under the ice, such as creatures of air and water, while around the equator lives aranea, with cyclopean temples, and other spidery creatures. The aranea and the others living around the equator would be menaced by creatures of ice coming from the polar caps.

Mario says the planet has a low atmospheric pressure, allowing visitors to feel light here, but is often hit by sandstorms. The planet has also a huge volcano, that the natives think inhabited by the Immortals. There is also an enormous valley which is about 2500 miles long, 400 wide and 6 miles deep, once a big river. Mario thinks the planet had a huge ocean once on the northern hemisphere, now a great desert with few canals. He confirms this world is inhabited by sandfolk, intelligent insects, aranea, salamanders, rockmen, minotaurs, dragons and some humans, whose original home could have been Mystara. Mario says the day on Vania is just a bit longer than on Mystara, but the seasons are longer, and so a Vanian year is almost two Mystaran years. In general, the climate in the northern hemisphere is more temperate than in the southern hemisphere. In the south, summers are hot and quick, winters long and cold.

Damocles and its belt - Asterius - Alith29 - Hersh30
Circumference at the equator: 19,173 miles31
An advanced civilization is mentioned on this planet by several sources, Mystaros indicates an advanced inhuman race here. DuBois instead mentions an asteroid belt here. As written above, he may confuse this location with the original Alphatian solar system, which should be outside Mystaraspace, but it seems indeed there are asteroids between Vaniae and Viudan and some are inhabited by wizards.
Damocles has a moon with an equatorial circumference of about 1,840 miles and three other irregular lesser moons with an equatorial circumference between 1,000 and 900 miles32.
Navarro mentions instead minor planets here called Razud, Koryis, Tyche, and Turmis33.
Note that according to some reports (Agathokles and Navarro) Asterius/Damocles would not be a sphere like the other planets but a hemisphere inhabited on the flat side, or even a coin shaped object. I cannot comment on the veracity of such claims.
According to general Agathokles’ report, it seems that among the more numerous races of Damocles there are some humanoid creatures with green skin with affinity to plants and insects, which have also founded the nation of Emerond in Davania, and pachydermions, intelligent elephants which also are known to live in some regions of Mystara. It seems the planet has also several other intelligent races34.
Some scholars, as Navarro and others, mention that the planet has been destroyed, but I have read conflicting reports on this. It is possible that some cosmic event or huge war has hit the planet recently, leading to the new orbit of the inner planet Alphatia.
According to Davidson, the asteroid field was formed by the destruction of the planet Arik. An ancient battle between Immortals and Outer Beings left this world shattered; various asteroids have been colonised over the years, but there is nothing substantial. Ghosts and spirits of the former inhabitants of Arik make their home here; the dark shadows hide beholders, fiends and undead.
Paniccia says that this world was colonised during the Blackmoor era and Blackmoorian descendants still live there. Other inhabitants would be elves and the people related to the Emerondians described by general Agathokles. He also says the planet is flat and these inhabitants are on the "top" side, while the "underworld" is inhabited by undead and plagued by some strange magical pollution. He also says that Blackmoorian ruins are to be found scattered across the planet.
Håvard confirms the Fifth Planet, Damocles in his map, is inhabited by the same people described by Agathokles, whom he names pyrithians, and they would be related to the Emerondians of Davania. He also says they originally came from a nearby solar system.
Robin says the alien illithids, also known as mind flayers, inhabit sections of this planet and some of the nearby asteroids.
Chimpman says the asteroids are inhabited by pyrithian pirates, and the Alphatians recently tried to build a big magical weapon there.

Mario says this planet was hit by some disaster twice, first around the time of the Great Rain of Fire, and the second time in recent years. However he maintains Damocles has not been completely destroyed and is still inhabited, as are many of the asteroids near it, some of which appear as small moons from the planet. The inhabitants are many, such as the pyrithians, Alphatians, visitors from other worlds, undead, intelligent insects, humans and pachydermions. Mario says that a day on Damocles last about 20 Mystaran hours and a season lasts about one Mystaran year, while on the asteroids the days last often much less, from 8 to 10 Mystaran hours. He says there are at least 40 asteroids with a circumference over 300 miles.

Tarastiae - Iuvis - Viudan - Ka - Landash/Watash - Zoar35 - Odir36
Circumference at the equator: 278,565 miles37
This planet is the first of the gigantic ones. It appears to be composed of gasses and so it does not have a surface which could be inhabited by normal creatures, but it may have elemental inhabitants. It has however an unknown number of moons, the four largest with an equatorial circumference between 6,100 and 10,285 miles, therefore almost equal to Matera or bigger.
Viudan has at least 63 minor moons, with equatorial circumferences ranging from 485 miles to less than one (with only 7 bigger than 90 miles).
Navarro names the 10 biggest moons as Diulanna, Maat, Viuden, Noumena, the twin moons Fredar and Fredara, Tiresias, Ssu-Ma, Madarua and Patura.
Mystaros indicates that some moons are inhabited.
The world of Landash/Watash described by DuBois could be one of the moons, where a culture of water wizards has supplanted a previous earth-based culture.
A mysterious Alphatian wizard known by the pseudonym of Ripvanwormer38 has published an extensive account on Tarastiae, as some Alphatian colonists would have named the planet. It is not clear if these Alphatians have contacts within the Alphatian Empire on Mystara. If they have, they are probably only secret contacts not widely known outside the empire.
Davidson describes a planet of grey clouds named Thanatos as the sixth, but I believe he could have inverted the position of Tarastiae and Khoronus, as his fifth planet is named Chronos. He describes this planet as a dark, almost black planet, a gas giant made up of swirling grey clouds. It is rarely visible from Mystara, but when it is it seems to gleam with a brightness that outshines the other planets; many cultures on Mystara view it as a herald of death to come. No explorers from Mystara have ventured there and returned, no scrying has yielded any information, so consequently nothing is known about the inhabitants of Thanatos.
Paniccia says that the inhabitants of this planet call it Eloysia and it has huge bubbles of breathable air in its atmosphere, with floating islands and human inhabitants.
Taylor says this planet has a huge floating continent in its atmosphere which appears as a red spot from a distance. He also says that one of the bigger moons is a water world, and another is a fire world, hot and volcanic, inhabited by efreeti, sollux and other fire loving creatures, including red, ruby and gold dragons. He later expanded this description adding that this world consists of a stack of huge plates, each about 1,000 miles thick and separated by about 5,000 miles. Each plate is distinctively-coloured giving the world its banded appearance. Each plate would have its own distinct environment and ecosystem. The biggest reddish flat world floating in the upper atmosphere of the southern hemisphere would be bigger than the whole of Mystara. He also names the four major moons as Zugzul, a fiery world of sulfurous volcanoes inhabited mostly by fire creatures and dragons, Petra, a water hollow moon, frozen on the outside but warmed by a central sun on the inside, Halav and Zirchev.
Håvard says the Sixth Planet, Khoronis in his map, is an air world made up of breathable air, with 63 floating continents inhabited by various races. The planet itself would be inhabited by air creatures and some colonies of Alphatian wizards. He also adds that some of the moons are hollow.
Robin says the planetary atmosphere is dominated by eternal storms and the elves have named the main moons after humanoid races; Ogre, Troll, Goblin, Orc and Kobold. Ogre and Troll have many craters, with Troll capturing atmosphere inside the craters. Goblin is highly volcanic, while Orc is covered by ice, but with a warm ocean sustaining life inside.
According to Ripvanwormer, the atmosphere of the planet has storms but is also inhabited by floating plants, winged serpents and flying insect-like beings. The planet’s major moons would be inhabited by dragons, stony giants and fiery creatures. A splinter group of Alphatian wizards, the Aurans, founded in the atmosphere of the planet twelve cities centuries ago, some of which were later invaded by archons. More recently, the Aurans were attacked by invaders from Khoronus, see below.

Mario confirms the atmosphere of this gigantic planet is inhabited by humans and flying creatures, and there are huge floating continents, one indeed almost as big as the whole of Mystara, about 20,000 miles wide and 10,000 miles high. A day on Tarastia is about 9.6 hours, while seasons last about 3 Mystaran years, but create little variations in temperatures, even if there are seasonal storms in the planet’s atmosphere.
Mario says that the biggest moon, with an equatorial circumference of 10,000 miles, is called Diulanna, or Halav or Ogre and has indeed an hidden ocean beneath the surface, inhabited by water creatures and water wizards, while the surface is inhabited by rockmen and strange humans. Mario then identifies Diulanna with Landash/Watash. A day on the moon lasts 7 Mystaran days.

[Sidebar: Tidal Locking]
Most of the moons of the solar system are tidally locked to their planet, so one face always looks at the planet, while the other never does. The only exceptions are normally the smaller and farthest satellites of the gas giants. This fact has interesting consequences on the inhabitants of the moon. Those living on the face looking at the planet, the gas giants in particular, have very bright days due to the light reflected by the planet, and may consider the planet more important than the distant sun in their myths. Those living on the other side instead may not even know they are orbiting a bigger planet. At night, those living on the face that looks at the planet may be unable to see the stars, or at least part of them, due to the mass of the gigantic planet to which the moon is tidally locked. Just think what kind of cultural shock an inhabitant of the far side may have if he/she travels to the near side, and vice versa.

The second biggest moon, called Maat, Zirchev or Troll, has an equatorial circumference of 9400 miles and many craters, and is inhabited mainly by stony giants and rockmen. A day lasts almost 17 Mystaran days. It is the farthest of the major moons from Tarastia .
The third biggest has an equatorial circumference of 7,150 miles, is called Viuden, Zugzul or Goblin and is full of volcanoes, fiery creatures and dragons. It is the major moon nearest to Tarastia and a day lasts 42 Mystaran hours.
The fourth biggest, called Noumena or Orc or Petra, has an equatorial circumference of 6,100 miles, is solid ice on the outside but has a warm ocean with aquatic life on the inside. The surface is inhabited only by ice creatures. A day lasts about 3.5 Mystaran days.
Mario says the sun is small as seen from these moons, but Tarastia is much bigger and brighter, with the other major moons appearing as bright stars.
Tarastia appears even bigger from Fredar or Frey, which has an irregular equatorial circumference of about 400 miles and from nearby Fredara or Freya, which has 200 miles of irregular equator. Both are inhabited by colonists from the major moons or other worlds.
Tiresias, which has an irregular equatorial circumference of 335 miles, see Tarastia as small as Sol is seen from Mystara, and Sol much smaller. This world would be inhabited too.
Ssu-Ma has an irregular equatorial circumference of 170 miles and is so far that Tarastia appears smaller than Mystara’s moon, but still brighter than the distant sun.
Madarua has an irregular circumference of 120 miles and is so far from Tarastia that the planet appears as small as the distant sun.
Patura has a circumference of 100 miles and is so near to Tarastia that the planet fills the whole sky on the side of the satellite which faces it.
Mario says there are six other major satellites ranging in circumference from 90 to 30 miles, and many more minor ones with a circumference from 16 to 2 miles. Many of them are relatively far from the planet, which they see as a bright star or a small moon, but almost everyone of them has or has had a base or a colony of some spacefaring culture, and most of them are often contested by people coming from Tarastia, its major moons or more far away places.


Khoronus - Mym39 - Temrim or Pathmeer40
Circumference at the equator: 235,814 miles41
Mystaros indicates a large draconic empire here and many lesser kingdoms. Khoronus is another gas giant with a ring of ice and asteroids around it. It has many moons, some as small as a few miles, but the biggest one has an equatorial circumference of 10,060 miles, so bigger than Matera and almost as big as Vaniae. Four other moons range in equatorial circumference from 2,985 to 2,075, similar to Patera or smaller, and two other moons have a circumference of less than 1,000 miles. Khoronus has 55 other moons, but only 6 of them have an equatorial circumference over 90 miles, ranging from 160 to 535 miles.
Navarro names the five biggest moons as Verthandi, Djaea, Petra, Taroyas and Halav, and says that Verthandi has its own skyshield and is possibly inhabited.
Davidson describes Chronos as a vast, ringed planet, with a rocky, windswept surface. The planet would have a dense, breathable atmosphere that encompasses dozens of moons, each itself habitable. Its heavy atmosphere retains heat well, making Chronos the ideal habitat for creatures native to the plane of air.
Paniccia says the atmosphere of the planet is poisonous, but the rings are inhabited, or at least several asteroids within them. He mentions dwarf mines and strange visitors from outer space, such as creatures called neogi, among the inhabitants of the rings.
Taylor says the atmosphere of this planet is made of habitable, solid clouds, while the rings are composed of crystalline shards. He describes three of the seven major moons: Kiranjo is a rocky world which suffered a cataclysmic impact from an asteroid of the Damocles belt; Djaea resembles a smaller version of Mystara, with a very similar climate; another unnamed moon has two halves, one light and one dark, with two very different ecosystems, the dark half covered with dense jungle, the light half a huge desert of pale sand.
Håvard says the Seventh Planet, Tarastiae in his map, is another air world with 27 floating continents. He says fierce storms rage across this world, but its atmosphere is nevertheless inhabited by blue and gold dragons, faenare and sky gnomes who arrived from the mythical gnomish city of Serraine in Mystara but lost contact with their homeland.
According to Robin this planet too has eternal storms in its atmosphere. Its main satellites would be named by the elves Deth (which has an atmosphere, but none ever returned from it), Melin, Mear and Mass (which would have many impact craters), Mob (highly volcanic,and tectonically active, with surface renewed often), Mag and Marc.
According to Ripvanwormer the planet is inhabited by colonists from the Nightmare dimension, diaboli, malferas and others who found the ruins of a lost carnifex colony on Khoronus.

Mario says the planet has indeed floating continents and many satellites. The great planet itself is inhabited by air creatures, dragons, gnomes and nightmare colonists.
A day on Khoronus is just 10.6 hours long and each season is 7 Mystaran years long.
The biggest moon, called Verthandi or Kiranjo or Deth, has a dense atmosphere and from the inside even the big shape of Khoronus with its rings and satellites appears dim. It has a circumference of 10,060 miles but Mario confirms it has the fame of a very dangerous place from which none ever returned, mostly because it has been colonized by nightmare creatures and has its share of dangerous monsters. A day here lasts 16 Mystaran days, but a face of this moon always looks to Khoronus and receives reflected light from it, making the day extremely bright, while the other face receives light from the distant sun, and has a less bright day. Regardless, the atmosphere is so thick that stars cannot be seen, even on the far side at night.
The second biggest moon has a circumference of 2,985 miles and is called Djaea or Mag, and it is overgrown with strange plants and full of fantastic animals. Its atmosphere is clear and Khoronus and its satellites can be seen from the surface in all their brightness and magnificence. A day on Djaea lasts about 4.5 Mystaran days.
The third biggest moon has a circumference of 2,870 miles and is called Taroyas or Marc, and has a dark half covered with dense jungle, and a light half with a desert of pale sand. It has also a strange equatorial ridge of mountains 12 miles high. Khoronus is like a big moon from here, and its satellites are the brightest stars. This moon has many different inhabitants, and colonizing diaboli. A day lasts 79 Mystaran days, and it is very hot, while the nights are very cold. The flora and the fauna have adapted to these particular circumstances.
The fourth biggest moon has a circumference of 2,190 miles and is called Halav or Melim, and is an icy world which nevertheless has native creatures and whole seas beneath the ice. A day on Halav lasts 2.74 Mystaran days.
The fifth biggest moon has a circumference of 2,075 miles and is called Petra or Mear and is another icy world with enclosed seas and native creatures. Khoronus is very big as seen from Melim and Mear, and its other moons appear as the brightest stars. A day on Petra lasts 1.9 Mystaran days.
Two other moons, Mass and Mob, have a circumferences of about 985 and 775 miles, the first one made of ice and rock, but with active geysers and an enclosed, inhabited sea, while the second one is just a rock of stone and ice with a single colony of diaboli and some strange native icy creatures. Both moons are close to Khoronus, which appears as big as the whole sky from them. The days on them last respectively 33 and 23 Mystaran hours.
Khoronus has 55 other moons, but only 6 of them have an equatorial circumference over 90 miles, ranging from 160 to 535 miles. They are rocky asteroids, sometimes with colonies or at least sky ports, at various distances from Khoronus.

Ordana - Razud - Eiryndul - Hak42
Circumference at the equator: 92,918 miles43.
Mystaros probably confuses Razud with Protius, as I believe his note about Protius only being known to Alphatians should instead refer to Razud. If the Alphatians indeed have secret bases there, the secret is well guarded. Razud does not have a solid surface but has several moons, the biggest five ranging in equatorial circumference from 3,080 to 1,130, so slightly bigger than Patera or smaller. Razud has at least 22 other minor moons, with an equatorial circumference ranging from 380 to 19 miles.
Navarro names this planet Ordana and says it has lush vegetation and a crystalline skyshield. The planet would have constantly changing seasons due to its peculiar rotation. Navarro also names the four biggest moons as Terra, Ka, Wayland, and Faunus, and writes that Terra is believed to be home to many earth-based creatures.
Davidson names the planet Eiryndul, describing it as a gas giant which reflects a pale green light. He says it has special interest for the Elves of Mystara, who view it as a bringer of luck. The serene green beauty of the planet from a distance belies the truth beneath, which is that the clouds that make up the planet are cold, caustic, and so very turbulent that any mortal contact with the strange creatures scryed living there has thus far been impossible.
Paniccia says this planet is inhabited by Alphatians with a city named Kabarkhand as the main port of call. He names some of the moons as Belthar, Delthar and Gammar.
Taylor names this planet Odin and says it is a huge water world with a hollow interior and five moons.
Håvard says the Eighth Planet is a water world, settled by Alphatian Followers of Water. Sea Creatures of all kinds, including Sea Giants would also live here, and he says the planet has 13 satellites.
Robin says this planet too has storms and the two major moons, Titania and Oberon, would be forested and inhabited by titans and fairy folks.

Mario says a day on Ordana is 17 Mystararan hours, but a season lasts for 21 Mystaran years, with huge springtime storms. He says the planet is very diverse, hence the different descriptions from many explorers. He confirms it has vegetation, seas, native inhabitants and Alphatian colonists. The length of the day on this planet is strange, with short days and nights at the equators, but days and nights which can last up to 42 years at the poles. Mario also cannot say if the solid ground of this planet is really fixed, or if he landed instead on huge floating continents.
The biggest moon, named Titania or Belthar or Terra, is inhabited by giants, earth creatures and fairy folk and has a circumference of 3,080 miles. A day here lasts for 9 Mystaran days at the equator, but here too days and nights can last up to 42 years at the poles, and this happens on all the moons of Ordana.
The second biggest, named Oberon, Delthar or Ka, has a circumference of 2,793 miles and a day of 13 Mystaran days. It has inhabitants similar to Terra, with many strange, big monsters.
The third moon, named Gammar or Wayland, has a circumference of 2,281 miles and a day of 4 Mystaran days. It would be mostly inhabited by giants.
The fourth moon, named Faunus, has a circumference of 2,258 miles and a day of 2.5 Mystaran days at the equator.
The fifth moon, so far unnamed by explorers, has a circumference of 920 miles and a day lasting 34 Mystaran hours. Ordana has at least 22 smaller moons ranging in circumference from 321 to 35 miles, some inhabited by colonists from the planet, the moons or other places.

Protius - Ka - Mwajin44
Circumference at the equator: 86,673 miles45
Mystaros indicates sea creatures on Razud, but I believe they should inhabit Protius, given the name of the planet. Protius apparently has no surface, but several moons. The biggest one has an equatorial circumference of 5,280 miles, two have a circumference of about 750 miles and ten others range from 375 to 75 miles.
Navarro says the planet is made of water and inhabited by water creatures. He also names the three biggest moons as Sinbad, Polonius, and Tallivai.
Davidson names the planet Ka, and while he confirms water is abundant, he says it is mostly in the form of ice, and the planet is inhabited mainly by hydrax.
Paniccia says this planet is an ocean of salty water and the native inhabitants are underwater creatures, but some humans and other air breathing races live here on artificial islands, and supposedly they came from other planets or they were the crew of flying ships which fell here.
Taylor says this planet is another water world, with only one major moon which he names Polonius.
Håvard says the Ninth Planet, Proteanis on his map, is a water world too, with many gates to the Elemental Plane of Water, water elementals and sea dragons. He also says the planet has 13 satellites. Some asteroids called the Three Sisters would also pass near its orbit.
Robin says that this planet also has eternal storms. Its three major moons would have been named by the elves Hot (which radiates warmth), Hel (dotted with craters) and Haven (which hosts an interior civilization of beholders).

Mario says a day on Protius is 16 Mystaran hours and a season lasts for 40 years, but seasonal variations are minimal. He says the atmosphere is thick and the planet has a huge ocean, with whole regions of ice, and is inhabited mostly by water creatures. There are however also floating and flying islands with air breathing races. The atmosphere is sometimes hit by terrible storms which can bring great destruction.
The first major moon, Sinbad, has a circumference of 5,280 miles and a day which lasts 6 Mystaran days. This moon has seas, ice, geyser and ice volcanoes46.
The second major moon, Polonius, has a circumference of about 800 miles, and the third, Tallivai, about 700. They are also inhabited by water creatures. Protius has 10 other moons ranging in circumference from 400 to 40 miles.

Helae - Hella47 - Nyx
Supposed circumference at the equator: 4,396 miles48.
This small planet is mentioned as Alphaks by Navarro, formed after the supposed upheaval which happened in the orbit of Asterius/Damocles. It could also be a lesser planet which came from the Comet Belt into this orbit.
Davidson describes this planet as Nyx, says it cannot be seen from Mystara without magic or technology. It is a small, bare planet, known to be made up of frozen poisonous gasses toxic to all known living things. According to Davidson, visitors have reported seeing some movement on the planet, and a race of metallic, spider like beings, rumoured to be the creators of the dreaded Meks, have been sighted.
Håvard says the Tenth Planet, Helae on his map, is an ice world inhabited by various ice creatures and frost giants. White and crystal dragons also have major strongholds here and, according to him, Charon has become a satellite of this world. The asteroid Big Rock should have an orbit near here, according to him.

A day on Hel lasts about 6 Mystaran days and a season is about 62 Mystaran years, with the winters making the planet even more freezing. Mario says Nyx is instead a satellite of Hel with a circumference of about 2,400 miles. Being the two bodies similar in dimensions, both are tidally locked, so one face of Hel always looks at the same face of Nyx. Mario says Alphaks is not here at all, but rather a satellite of Charon (see below).
He says both worlds are inhabited by many strange creatures, apparently constructs, undead and strange insectoid creatures.

Charon - Thanatos - Alphaks
Circumference at the equator: 16,713 miles49.
Charon is a rocky, ice planet with five moons50. The biggest one has an equatorial circumference of 2,355 miles, two have a circumference of 300 miles and the smaller two of 35 miles or less.
Mystaros says Charon is known only to Alphatians.
Navarro says the planet is inhabited by undead and names the biggest moon as Marwdyn, and says it is formed of ice or the skull bone of some gargantuan space creature.
Taylor says Charon is hollow, and the cold surface is inhabited by fungoid trees and strange constructs known as meks. The inner world however has a central sun, seas and wooden lands. He says that a sargasso 'curtain' covers the entrance to the world interior, but In recent times a number of spaceports have grown up around the rim of the hole, and various beacons and warning lights have been built. The largest would be the city of Asterius' Boon, built on a river delta near the boundary of the sargasso. There is some evidence that the immortal Asterius himself had something to do with the founding of the city. The population of the inner sphere consists of the descendants of the crews of ships that crashed due to the entrance sargasso. He does not specify if the hollow world has native life.
Håvard says the Eleventh Planet, Thanatoi in his map, is home to undead and other servants of Entropy. Night Dragons are believed to have a stronghold here.
Robin says this world is called Chagas by the elves.

Mario says a day on Charon is 26 hours long but seasons last for 140 years. He reports that Charon has indeed a spaceport and many native inhabitants. Thanatos would be the biggest moon, and the two minor ones would be Alphaks and Marwdyn. He did not have much information on these worlds, so maybe they are really inhabited by entropic creatures.

The Comet Belt and the dwarf planets

This region at the border of Mystara’s solar system is not only full of comets, which normally have very elliptical orbits bringing them near to Mystara and the other planets, but it also has several dwarf planets.
The nine biggest51 have an equatorial circumference ranging from 4,550 to 1,646 miles, so about the dimensions of the inhabited Mystara moons. Yet in this region so far from the sun it is hard to imagine what kind of life forms could ever survive.
Navarro also mentions a comet named Hel with an orbit of 76 years.


Outer space is vast and sages and explorers say many worlds exist beyond the planets which circle the same sun of Mystara52. Knowledge of them is limited, but in some libraries of the Known World there are indeed reports of people who claim to have visited far away worlds. Tales which are hard to verify, unless you have a flying ship, or somehow you can board one, and go exploring the endless night.

1See also Threshold #9, "Ecology of the Megaliths and the Norns Cycle" by LoZompatore and this post on Robin’s blog.

2Indeed he is, see his works here:

3Immortal Boxed Set, DM’s Guide to Immortals page 5 and 6.

4In the[Mystaraspace] Tarastia” thread of the Spelljammer forum at the Piazza.

5In the Blackmoorspace Week” thread in the Spelljammer forum at the Piazza.

6Note that RobJN has his own version of Mystara as explained in the article dedicated to Thorn’s Mystara in Threshold issue #1, page 74.

7See the discussion by Robin, Ripvanwormer, Håvard and others in this thread on the Piazza forum:

8See Stefano’s article in this issue of Threshold.

9This fictional character is the mean I have chosen to detail my own ideas about Mystara’s solar system.

10See the Exiles Campaign article by John Calvin in this same issue of Threshold and other material here:

11Obviously John Calvin mentions the Nithians, but from a Mystaran perspective the Spell of Oblivion would prevent him from knowing of them, so I have substitute them with the Thothians. See also my articles in Threshold issue 11 and 12 for more about the topic.

12See also Dragon Magazine 258 pg 31 Mage vs machine and Dragon Magazine 270 pg 34 Revenge of the sheens by Bruce R. Cordell.

13Oards appeared in CM6 Where Chaos reigns and AC9 Creature Catalogue. The Mek appears in the Rules Cyclopedia and the Mystara AD&D Monstrous Compendium Appendix. More informations about them are available at the Vault of Pandius.

14Such as any race which appears in the Spelljammer setting: The adaptors are described in the Rules Cyclopedia.

15As given by Frank Mentzer, roughly the same as Earth’s Sun.

16Elven name meaning “The New One”.

17Indicated by Frank Mentzer only after the possible destruction of Asterius/Damocles, which I will not given as already happened. Supposed circumference as Mercury.

18This would be the elven name as written in the starmap of the module CM7 The Tree of Life. The correspondence between the planets and those names was discussed by Robin and ripvanwormer in a recent thread on The Piazza: I have chosen to use Ripvanwormer’s ideas, but Robin proposed alternative correspondences.

19This would be the Blackmoorian name as proposed by ripvanwormer. Phellia was the Thonian name of Valerias, see also Immortals of Blackmoor vs ZGG Deities by Håvard and Marco Dalmonte

20As given by Frank Mentzer, see note 4, Valerias is slightly larger than Venus.

21See Spelljammer’s Elven Imperial Navy:

22Check his article in this same issue of Threshold magazine!

23As given by Frank Mentzer. Thorfinn Tait here reached a similar value, while I here calculated that Mystara could even be a little bigger. The circumference of 19,448 miles given in the Hollow World Boxed set is clearly wrong as it does not fit with the other existing canon maps.

24See here and here on the vaults about Matera and Patera and obviously the articles on the Hollow Moon by Chimpman in this and previous issues of Threshold magazine, and the articles on Myoshima and Patera by Agathokles in this issue for much more details about Mystara’s moons.

25See note 21. The elven name would mean “flower” for the bright colour of the planet.

26See note 22. Named after a the Thonian name of Ka or Zugzul, the Afridhi Fire God.

27As given by Frank Mentzer. Vaniae is a bit smaller than Mars.

28Actually the Nithians, but the author cannot know this due to the Spell of Oblivion, check Gazetteer 2 the Emirates of Ylaruam or HWR2 Kingdom of Nithia.

29See note 21. The elven name would mean “Fair” or “Beautiful”.

30See note 22. Named after the Thonian name of Korotiku or Tyche.

31As given by Frank Mentzer. In the Immortal set Damocles is supposed to be destroyed in a few or few thousands years by natural means or the actions of its resident. It is also said it may contain an advanced civilization. Damocles’ debris would create a Mercury-like and a Pluto-like planet in Mystara’s Solar System and an asteroid belt, and some of the moons of the gas giants. Fan speculated the meteor which hit Darokin in the canon events of the Wrath of the Immortals boxed set could have been from the destruction of Damocles, but here I will assume the planet as still existing.

32Inspired by Ceres and other asteroids of the asteroid belt.

33Ceres and the other asteroids in this case would not be moons of Damocles but would have their own independent orbits in the same region of the system.

34See also Damocles Q&A by Giampaolo Agosta here:

35See note 21. The elven word would mean “Splendor” or “Radiance”.

36See note 22. Named after the Thonian name of the Immortal Odin.

37As given by Frank Mentzer. Viudan is slightly bigger than Jupiter.

38See this thread in the Spelljammer forum:

39See note 21. The elven name would mean “Bird”.

40See note 22. Temrin was proposed by Ripvanwormer as corresponding to Thanatos, but the planet could have been named Khoronus, or to the more ancient Immortal Pathmeer/Fugit.

41As given by Frank Mentzer. Khoronus is just a bit bigger than Saturn.

42See note 22. Peshwa name of Simurgh or Odin.

43As given by Frank Mentzer. Razud is slightly bigger than Uranus.

44See note 22. Thonian name of Protius or Sinbad.

45As given by Frank Mentzer. Protius is smaller than Neptune.

46See Cryovolcano:

47See note 22. Thonian name of Hel.

48As given by Frank Mentzer. M-Charon is much bigger than the real Pluto and Charon.

49As given by Frank Mentzer. M-Charon is much bigger than the real Pluto and Charon.

50Inspired by the moons of Pluto.

51Inspired by Eris, Makemake and the other Kuiper belt dwarf planets.

52See for example Mystara related crystal spheres by John Calvin and his Exiles article in this same issue of Threshold, Adjacent Solar Systems/Crystal Spheres by Håvard and Adjacent Solar Systems/Crystal Spheres by Ripvanwormer