The Movable Ephemeris and the Gloranthan Sky

The Moveable Ephemeris is the computer version of the famous “machine that marched with the sky” in Yuthuppa.

Click here to see the Gloranthan sky… (maybe)

If Java is installed on your computer and enabled in your web browser, the Ephemeris should display in a separate window.


It’s now (2020) often difficult to run java applets in web browsers. Make sure you have java installed. Click here to download the zipped Ephemeris java app, unzip and run the EphemerisII.class file.

MacOS Instructions

Tested on Mohave, Catalina and Big Sur, December 2020

Apple Menu > System Preferences. look at the bottom row, if you see Java, ignore the download Java bit next.

Download Java SE 8 JRE…/javase-jre8-downloads.html… and install it.

Now download the ephemeris zip file from and unzip it. It should be in your downloads folder. In that folder full of gibberish names, find EphemerisII.class and double click it. That should run the ephemeris.

If you want to take a closer look at the app, the source code is on Mr. Tines website.

The Gloranthan Ephemeris is Copyrighted 2013 by Moon Design. Big time thanks to Nick Brooke, Alex Ferguson and Mr. Tines for their hard work on the Ephemeris.


THE SKY OF GLORANTHA is made of several huge domes covering the earth. The innermost domes, closest to the surface world, are transparent. The outer one is opaque, though pierced by star holes.

In the daytime the sky is ruled by Yelm, the sun god, and shines bright blue; only rarely are planets or stars visible. When Yelm descends to the Underworld out pours Xentha, Goddess of Night, with her  resplendent cloak. The darkness is broken by thousands of tiny bright stars and punctuated by several prominent heavenly bodies. Most visible among the heavenly bodies are the Red Moon, a Fixed Body; Tolat, a red planet; Wagon, a planet; Lorion, a constellation; and Orlanth’s Ring, a special phenomenon.

The sky dome rocks on a north-south axis. In summer it tilts north, exposing stars in the south which are invisible in the winter and sending the sun’s path to the north of the center of the sky. In winter the dome rocks back, exposing northern stars and concealing the southern, and making the sun’s path cross the sky south of the center. The God Learners believed that the sky spilled its “burningness” during its winter tilt, warming the southlands and making the Ocean of Fire there.

The dome also daily rotates counter-clockwise about its axis, as seen from below. This gives the impression that the stars move clockwise around the Pole Star each night.



The stars are holes in the sky through which light leaks, becoming visible at night. They appear as pinpricks of light. They are fixed in place and appear to move only because the whole sky dome moves. Thousands dot the sky; many are clustered into constellations. Some especially important stars are:

Dark Spot

Dayzatar’s Eye

One Night Wish

Pole Star



Some extraordinary star clusters are of recognized importance across the world. The most important among them are:


Bad One

Draconis Stella


Ice Palace


Love Stars

Sword Stars



War Stars

Many other constellations are recognized locally, but not across the whole world. Several of the stars around the Red Moon, for instance, are said to be her Heroes’ On the star maps you will see the rotation of the constellations with the seasons.


Some heavenly bodies seem to rise and fall in a limited part of the horizon. They are called Jumpers because they leap up, then fall down in the same area. The Jumpers are:

Dawn Star

Dusk Star



Some heavenly bodies do not conform to the sky dome’s regular movements. These are termed planets. Most of them travel east to west along one of two pathways, called Sunpath and Southpath. Except for Tolat, they are invisible in daytime, except quite near dawn or dusk.

The Sunpath Planets: The Sunpath covers precisely the same part of the sky which Yelm traverses in his daily travel. Lightfore marks it most prominently with his nightly passage. The four planets that travel the Sunpath are:





The Southpath Planets: The Southpath is a regular, but highly mobile, pathway across the sky. Its eastern end, unmarked by any clear constellations, is called the Eastern Mouth, while the western place where the planets set is called the Dodging Gate. The meanings of these terms are unclear, but they are widespread and equivalent terms are found in many languages. The planets that travel the Southpath are:





Some celestial bodies do not move from their place in the sky and are called Fixed bodies. These include:

Red Moon




Some heavenly bodies do not fit any other category, being special planets or constellations. They include:

Blue Moon


Lonely Cry

Lost Rocks

Orlanth’s Ring

Sky Storm


Arkat: This constellation became prominent at the beginning of the Second Age as Arkat prepared it to be the site of his retirement. Three stars, one of which blinks regularly, are visible around it, and several others are less so. This is still considered to be the residence of this First Age hero.

Artia: This tiny red light travels east to west along the Southpath both day and night and takes eight weeks to traverse the sky. It then disappears for another eight weeks. It cannot be seen in the sky for the two weeks of Theyalan Sacred Time.

Bad One: This constellation has many names in different regions, all of which connote something bad about this part of the sky and these stars in particular. The Theyalans, for instance, call it Ragnaglar’s Remains, the Solar cultists call it the Demonic Scorpion, and the Doraddi call it Filth Which Flies.

Blue Moon: The Blue Moon is mentioned as a prominent heavenly body in many Godtime tales, but changed significantly before Time began. It climbs along the upper Sky Dome and is thus invisible to observers on earth. It takes one to six days to climb to the center of the sky, whereupon it plummets rapidly from Pole Star down through the center of Magasta’s Pool. As it drops, it is sometimes visible as the Blue Streak. The moon then travels through the Underworld to the eastern sky and begins the ascent again. The BlueMoon commands the ocean tides. During its climb, the tides slowly creep up. When the moon falls through Magasta’s Pool, the tides precipitously drop to their lowest point.

Dark Spot: One part of the sky is darker than night, like a hole in the heavens. Most people do not know of is origin and have conjured frightening tales of its creation. Among the Lunar Empire peoples it is known to be the place where the star of Sheng Seleris used to be until extinguished by their emperor.

Dawn Star: This white star appears in the sky, increases radiance from dim to piercing bright, then vanishes, encompassed by the brighter sun. It sets in the east from whence it rose. It appears about three hours before dawn in the winter, and about six hours before dawn in the summer. In winter it sets about three hours after sunrise, and in summer about six. It is called Theya in most Genertelan languages.

Dayzatar’s Eye: This star is one of the brightest in the heavens. It was once located where the Pole Star is, but has now shifted.

Draconis Stella: This constellation is the largest in the sky. Although it has several different names all of them refer to it as a draconic type of creature, and most of them agree that the green star in Orlanth’s Ring was once part of this constellation. The Orlanthi have a popular myth of how their god conquered the Father and Mother of Dragons and left the remains in heaven.

Dusk Star: After the sun sets this star remains behind on the western horizon, its fiery blood-red glow fading after about three hours in the wintertime, and after about six hours in the summer. It does not appear to rise, presumably because the setting sun blocks it. In most Genertelan tongues it is called Rausa.

Hunt: The Hunt is a prominent constellation of eight stars. Most mythologies agree that this  constellation had something to do with an ancient hunt, but do not agree on who the hunters were, what their prey was, nor which stars are which.

Ice Palace: This northern constellation is visible only in winter. Some people say it is Valind’s palace. At midwinter it sits above the northern horizon, but is on the horizon in spring and fall, and invisible in summer.

Jugger: This planetary body has been seen to cross the sky along unusual paths which are far from following the normal east-to-west path of the sun and most planets. At times the Jugger disappears from the sky for as much as a century at a time. Since the origin of time astrologers have charted this grey planet and claim that it has, incredibly, crushed other stars and disrupted the passage of regular planets. One discredited, but wise, scholar said “This is the Juggernaut of Heaven, and even Yelm fears it.”

Kalikos: This star rises every night in the north-northwest and sets in the same place before sunrise. It rises the highest in winter, and is sometimes not visible in summer. Kalikos is a hero of many northern people, and is credited with ending the Great Winter of Godtime.

Lightfore: This prominent yellow body of light travels nightly from east to west exactly on Yelm’s path. It rises when Yelm sinks and sets when Yelm rises. It is sometimes called the “little sun.” Lightfore is the object of a hero cult worshipped by many people who fear the night.

Lonely Cry: On five nights a year this phenomenon might be visible, but its appearance is erratic. It looks like a band of lustral ribbons snaking skyward, slowly dissolving as they reach higher. Theyalans gave it this name, saying it is a god reaching out from his under-world prison for assistance which will never come. The Pamaltelans, on the other hand, call it The Kiss, and say it marks the site of a secret meeting between immortals which has long since been exposed.

Lorion: This special body is a bright constellation of nine stars which is visible year-round. New Year Day is marked when the sun rises exactly along it. In mid-summer it sits low in the southern sky, partially obscured by the horizon, in fall it marks the western Dusk Gates, and in midwinter it sits high in the north, above the Ice Palace. Lorion is usually considered to be a water god and lord of the celestial river.

Lost Rocks: This is a cluster of lights, three of which are easily visible, which wander across the sky in an extremely erratic pattern. They rise and fall in no discernable pattern except that they always rise east of the north/south line, and set west of it. Once they rose and set within a few hours, just peeping up over the  southernmost region, marking their shortest appearance. Their longest was in the Second Age when they rose from the north-northeast, wandered back and forth in the sky for seven years, then set in the north-northwest. Their time in the underworld is as erratic. The Orlanthi claim that this is the remains of Giant Ganvaktakarn, one of their god’s ancient foes.

Love Stars: This cluster of stars includes hundreds of tiny lights but few bright ones. It appears as a smudge in the sky, gradually thinning outward from a long central blur. Histipis the Star-seer said in the Second Age that two planets, invisible except to him, circled in that part of the sky. When they were close  together within this region they generated the many stars as babies.

Mastakos: A blue body which crosses the sky in eight hours along the Sunpath, then rises immediately in the east again. How it skips its traverse of the Underworld is unknown, but the worshippers of Orlanth say it is the god of Movement.

Moskalf: This white planet travels the Sunpath in thirty one days, disappears for an equal length of time, then appears again in the east.

One Night Wish: This star appears only for a short time at midsummer, peeking shyly over the horizon. Many people have a tradition of making a wish upon this star, believing that it carries special messages to the gods.

Orlanth’s Ring: Orlanth is one of the greatest deities in Glorantha. This constellation has seven orange stars and one prominent green star, called the Dragon’s Head. It appears at the edge of the Middle Sky when it rises, never appearing in the Lower Sky. It takes one full week to travel upward along the sky dome into the Pole Star. Because it travels upward as the sky dome turns, when viewed from below the constellation traces a spiral air rune in the sky each week. It disappears for a week before appearing again.

Pole Star: This bright star is visible all night and briefly each day just before sunset and after dawn. The Pole Star only moves in a slow yearly wobble with the sky dome’s tilt, and the other stars move in a circle around it. It is a stable reference point, marking the place where the Spike once pierced the sky dome. Worshippers of the sky gods consider Pole Star to be the leader of the sun god’s army.

Red Moon: The red moon is unique because it never moves, day or night, from its place in the northwestern sky. Of all heavenly bodies, only it is also visible all day while the sun shines. Day and night the visible face of the moon is either bright red, black, or both. At full moon it is completely bright red. As its phases progress the red shrinks, replaced by darkness creeping around it. The crescent of darkness grows to cover half the moon, then three quarters, until the last bit of light disappears. When black, the moon is visible in daytime, though not at night. It remains black for two days, when the red light creeps in again and grows to full. The entire cycle takes seven days and nights. However, this changes of phases is not the same across all Glorantha: while one place is experiencing a Crescent, another sees the Black Phase. The Red Moon is said to be the body of the goddess worshipped by the citizens of the Lunar Empire.

Sky Storm: The Sky Storm is a very unusual celestial phenomenon. At times, and no one has ever correctly prophesied or calculated the times, bursts of brilliant lights, scintillating clouds, and blinding color patterns appear to swirl and explode around the Pole Star, usually encompassing Dayzatar’s Eye as well. The effect is usually its largest in the winter, at its least in the spring and autumn, and most common, but only moderately sized, in the summer.

Stormgate: This small star, often not visible to the naked eye, is a Fixed Body in the sky. From it  emerges Orlanth’s Ring when it begins its ascent.

Sun: Yelm daily rises from the Gate of the East, travels through the sky for about L2 hours, then disappears into the Western Gate and is gone for about 12 hours as he traverses the Underworld. In spring and autumn his path is roughly through the middle of the sky. In winter his path lies to the south, and the orb is visibly paler than usual. In summer his path is north of the Pole Star, and he is brighter than usual. Yelm is worshipped by many people.

Sword Stars: The Sword Stars form a constellation marking the edge between the Lower and Middle Heavens. They sit in the northern horizon, and in summer ale on the horizon, but in winter are high in the sky. The barbarians of Genertela consider this to be the house of Humakt, their war god.

Shargash: This blood-red planer takes two weeks to traverse the sky along the Southpath, then spends two weeks in the underworld. It is the largest of the planets, and its round shape is quite discernable in the sky, even during the day. Many peoples claim it is propitious to make war while this planet is visible, while others claim it is propitious for begetting babies. The deity of this planet is the deity for the city of Alkoth.

Tree. This constellation has one of two visible bodies of green light in the sky. It is the place where Flamal retreated after his body was mutilated. The elves call it Seedplace.

Twinstar: Two planets, traveling close together, cross the sky in three days, traveling south of the Sunpath. They vanish for three days then reappear. The Twinstars are yellowish-white.

Wagon: A large pale planet which takes 98 days and nights to travel east to west along the Sunpath, then disappears for an equal time. The worshippers of the sky gods say this is their god Lokarnos. The Theyalans call it the Mule and say it is the beast of Issaries.

War Stars: This is one of two large clusters of stars. It includes hundreds of tiny lights but few bright ones. It appears as the smaller smudge in the sky, gradually thinning outward from a long central blur. Histipis the Star-seer, a God Learner, said that two planets, invisible except to him, circled in that part of the sky. When they were close together within this region they generated these many stars as chunks of flesh chopped off of each other in combat.

Whisperers: This constellation is believed by Pamaltelans to be where Shamans enter the spirit world to learn secrets which normal folk cannot hear, hence the whispering. The westerners of Genertela say that a great silence which once covered the world came from this place.

Youth: This is said to be the residence of the Spirit of Youth, or perhaps his body. It is invisible for the winter season.

Zenith: This is another of the Fixed Bodies. Different languages all call it by some synonym of Zenith even though it is clearly not at the zenith of the sky. Most stories also say that the name was given in ages past by the dwarfs.

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