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Arcana Mystara: Mystaran Astronomy

by Kit Navarro

The Planets of Astronomy

Astronomers of the Known World classify the heavenly bodies closest to Mystara into the Sun; the Lesser Planets, Alphatia, Valerias, Mystara, Rathanos or Vanya; the Minor Planets, found in the Tears of Asterius asteroid belt; the Greater Planets, Tarastia and Khoronus; and the Outer Planets: Ordana, Protius, Thanatos.

Ixion the Sun

The Sun is the centre of the Mystaran solar system and its primary source of natural heat and light. For ages, astronomers have speculated how intense the fires of the Sun. According to an ancient legend of the Flaems, a race of fire-loving wanderers from Old Alphatia, the Sun is inhabited by creatures from the Elemental Plane of Fire, governed by a Fire Elemental Ruler, whose domain is a large black hollow sphere within the core of the sun.

The Lesser Planets

The planets closest to the Sun and of relatively small size are considered the Lesser Planets. These include Valerias, Mystara, Vanya (Rathanos in Alphatian tradition), Asterius formerly, and recently, Alphatia. All the Lesser Planets are spherical, solid masses, greatly affected by their proximity to the sun.


This Lesser Planet was born from the destruction of the Planet Asterius sometime around AC 1000. It was originally an irregular chunk of rock, much like its counterpart Alphaks, pulled towards the sun rather than away from it. The extreme heat and tremendous pressure from Ixion purified the imperfect mass of matter, giving birth to a flawless sphere of brilliant crystal, or as some astronomers suggest, pure diamond. This sparkling new heavenly body was named Alphatia, after the Patroness of Arts, and sometimes rivals the beautiful Planet of Valerias in radiance, particularly during the winter nights. However, Alphatia's brilliant surface and the extreme brightness from Ixion make it difficult to view Alphatia directly, and many astronomers have gone blind in attempting to view this beautiful new planet.


The Planet Valerias was named after the Patroness of Beauty and Love, not only because of it luminous beauty in the night sky, but also because it is believed to be closest to the sun, Ixion. According to old romantic myths, the planet was a perfect paradise where its beautiful, loving inhabitants lived in peace and harmony. But astronomers soon discovered that Valerias is actually bathed in swirling multicoloured gases, which are as caustic and toxic as they are pretty. It is generally believed the planet cannot even support life, but some stargazers claim to have seen draconic creatures flying through the gaseous clouds. These creatures were surmised be gemstone dragons, their deadly dragon breath contributing to the already poisonous atmosphere.


Once believed to be the centre of the universe, astronomers have reasonably come to the conclusion that Mystara is just one of the planets revolving around the sun Ixion. It is home to various forms of life, and many civilisations, and is highly magical in nature. It has two moons, the visible one, Matera, and an invisible one, Patera. There have been recent rumours that Mystara is actually hollow, with entrances into the interior through the polar caps, but idea is disregarded as a hoax by many.


The planet from the sun after Mystara is called Rathanos by the astronomers of Alphatia, and Vanya by the Thyatian tradition, both with good cause. Throughout its two-year cycle around the sun, this planet undergoes severe changes of seasons and environments. When travelling away from Ixion, this planet is covered with snow and ice, giving it a silver-grey sheen, ascribed to the Grey Lady of Thyatian myth. When orbiting closer to the sun, the ice melts, and the barren planet surface bursts into fiery-red flames, hence its association with Rathanos, the Patron of Fire. Astronomers believe that a breed of salamanders, which can shift natures from fire to frost and back again, inhabit this planet of opposite extremes.

This planet has two moons, Palson and Donar. The second moon, Donar, is believed to be a gigantic ball of lightning, and occasionally causes violent thunderstorms on the surface of the planet.


Even before its destruction, the planet Asterius had long baffled astronomical scholars throughout the centuries. Asterius was an exception to the rule that all Lesser Planets were spherical, as it was proved flat like a silver coin, occasionally flipping on itself, hence the ancient named it after the Patron of Money.

Of all the planets around the sun, Asterius was believed to be the most likely to be inhabited, not just with life, but also with a thriving civilisation. But none of these conjectures were ever proven, as some time in AC 1000, the planet was destroyed. The most commonly accepted idea is that the comet Hel collided with the planet.

The Minor Planets

What astronomers of Mystara consider Minor Planets are the small heavenly bodies that regularly circle the sun. These Minor Planets are usually irregularly-shaped masses, mostly of rock, ice or other solid matter, and are too small to have a skyshield of their own-although this does not mean they are not inhabited. The belt of asteroids created by the destruction of Asterius, now called the Tears of Asterius, hold the most Minor Planets. The largest of these are Razud, Koryis, Tyche, and Turmis, each born from the destruction of Asterius, but by far, the most famous of these was the Great Meteor, which crashed into Mystara in AC 1006, devastating the border of Darokin and Glantri.

Some astronomers also consider the planet Alphaks a Minor Planet.

The Greater Planets

The two Greater Planets, Tarastia and Khoronus, lie just beyond the planet Asterius, and later the asteroids called the Tears of Asterius. These two giants each more than 10 times the size of Mystara, and for centuries, sages claimed that these planets are inhabited by giants, titans, behemoths, and other gargantuan creatures-some of which may have arrived on Mystara-but such terrifying conjectures have never been proven.


The Great Planet Tarastia is largest of the planets, more than 14 times the size of Mystara. It lies beyond Asterius-and later, the Tears of Asterius-about 5 times further from the sun than Mystara, and its journey around the sun spans about 12 years.

Sages believe that the immense size of Tarastia is because it is merely a large ball of air and gas. Some astronomers construe that so much gases and fumes can only come from an inner core of extreme heat-possibly made of elemental fire or from a gate to the Plane of Fire. Doomsayers whisper that Tarastia will one day explode like a great fireball that will rival Ixion, and engulf all the other planets, including Mystara.

Tarastia has the most moons among all the planets. The eight largest were identified and named since ancient times: Diulanna, Maat, Viuden, Noumena, the twin moons Fredar and Fredara (identical in size and always close to each other), Tiresias, and Ssu-Ma. The two smallest moons, Madarua and Patura, were discovered only at the turn of the Thyatian Millennium. Astronomers believe there could be more moons to be discovered.


The second Greater Planet, Khoronus, is almost 13 times as large as Mystara, and lies almost 10 times as far from the sun. It takes 30 years for Khoronus to travel around the sun.

The most striking feature of Khoronus is that is has rings circling around it. Sages argue as to the nature of these multicoloured bands. Some say they are made of light, much like a rainbow. Some say they are powerful magical energies from the planet. Others say these are the bones and ashes of a great cosmic serpent that tried to swallow Khoronus. Others say they are simply chunks of earth and shards of ice, or debris from an exploded moon.

Khoronus is known to have five moons (Verthandi, Djaea, Petra, Taroyas, and Halav), which orbit around the planet just beyond its rings. The largest Verthandi is said to have its own skyshield and is possibly inhabited.

The Outer Planets

The planets of Ordana, Protius, and Thanatos orbit so far away from the sun that they cannot be seen from Mystara with the aid of magic. Astronomers believe that the Outer Planets are highly charged with magical energies, and thus, despite their apparent distance, hold powerful influence on Mystara-and the Prime Plane itself. Ancient sages believe that each Greater Planet was a project of the Immortals, perhaps as an experimental testing ground for new creatures, new environments or new forms of magic. Others says that the creation of the Outer Planets was part of the tasks of Immortality, while some claim, the these cosmic bodies reek with the energies of the Old Ones.


Ordana was named after the Forest Mother, because of its green hue, which sages believe is from the lush vegetation that grows on it. Although it lies 19 times further from the sun than Mystara, Ordana has a crystalline skyshield that magnifies the life-giving energy of the sun and contains it like a greenhouse.

The planet Ordana is peculiar in that as it rotates, it wobbles-so much so that it sometimes spins on its sides. Astronomers first discovered this unique phenomenon by following the curious paths of its moons, sometimes on a horizontal circle like in most other planets, and sometimes on a vertical ring from what appears to be the northern and southern poles. Because of its shifting axis, astrologers surmise that Ordana has constantly changing seasons, much more so than is expected in its cycle around the sun, which is about 85 years long.

Ordana has four moons, named Terra, Ka, Wayland, and Faunus. The largest, Terra, is slightly smaller than Mystara but believed to be home to many earth-based creatures.


The second of the Outer Planets is named Protius, after the Old Man of the Sea. It is blue is colour and is said to be made most, if not entirely, of water. Sages surmise it is inhabited by water-dwelling creatures similar to those found on Mystara, and that its core has a gate that opens into the Elemental Plane of Water.

Protius is about the same size of Ordana and its path travels 30 times farther from the sun than Mystara's, and it takes 165 years to travel around the sun.

It has three moons, named Sinbad, Polonius, and Tallivai.


With the destruction of the planet Asterius in AC 1000, this irregular chunk of rock was jettisoned into space, and became a source of much contention among the astronomers of Mystara. Some consider it an Outer Planet, as it found find an orbit (albeit a highly irregular one) between the planets Protius and Thanatos. Some consider it only a Minor Planet, being only slightly larger than the planetoid Koryis. Some do not even consider it a planet, and classify it as an asteroid or a comet, like Hel. The one thing sages agree upon is its name: Alphaks, after the chaotic Roaring Fiend from the Sphere of Entropy.

At certain unpredictable occasions, Alphaks crosses over the path of Thanatos-a phenomenon called "Alphaks crossing"-making it the furthest planet from the sun. Astronomers have yet to fully investigate and understand this mysterious phenomenon.


The last of the Outer Planets is named after the Grim Reaper, Thanatos. About 40 times further away from the sun than Mystara, Thanatos is a cold, dark and lonely planet. Astronomers uncover very little about this mysterious planet, as it seems to resist most forms of stargazing magic. Some sages account this to its vast distance, but others think most sinister forces are at work on Thanatos. Ancient Alphatian astronomers once believed that Thanatos is teeming with undead who flourish being so far away from the light of the sun. The necromantic magic of these undead creatures, or the negative energies from their very nature, prevents living beings from other planets to learn of their existence.

Thanatos has one moon, Marwdyn, which is a little more than a large chunk of ice-or the skull bone of some gargantuan space creature. Thanatos takes 247 years to make a cycle around the sun, and its path is sometimes crossed by the erratic planet Alphaks.


The comet Hel has been observed from Mystara for millennia, its earliest recorded sighting before the rise of the Nithian Empire, about the time of the Great Rain of Fire. Astrologers have always interpreted the appearance of Hel's Comet (or simply Hel) as a portent of doom, and have linked it with numerous disasters throughout history, such as the Alphatian Landfall, the destruction of Nithia, the arrival of the d'Ambrevilles, and recently, the Wrath of the Immortals War.

Hel's Comet is a ball of spinning gas and particles, sometimes burning brightly and sometimes burnt out and dark. It takes about 76 years for it to travel around its elliptical orbit around the sun. Its orbit is not on the same plane as the other planets, and thus, its collision with the planet Asterius was a highly improbable, unfortunately tragic, possibility.

Planets in the Mystaran Solar System

Planets Glyph Shape Type Size Diameter (miles) Distance from Sun (million of miles)
Ixion Spherical Fire H 864,000 -
Alphatia Spherical Earth D 3,050 36
Valerias Spherical Earth E 7,581 67
Mystara Spherical Earth E 6,190 92
Vanya (Rathanos) Spherical Earth E 4,200 141
Tears of Asterius (formerly Asterius) Belt (formerly Flatworld) Earth B (formerly E) Varies from 10 to 430 miles, (formerly 6,103) Average of 300 million miles, (formerly 257)
Tarastia Spherical Air G 88,670 483
Khoronus Spherical Air G 75,062 887
Ordana Spherical Earth F 29,577 1783
Protius Spherical Water F 27,589 2794
Alphaks Irregular Earth D 1,400 3666
Thanatos Cluster Water E 5,320 7105
Hel Irregular Air C 610 Varies