Tarack, Volcanic Moon of Galentor

This is a write up of Tarack, the Moon of Galentor in the Galen Alpha planetary system, a setting for the Tyranny of the Daleks scenario, using the Second Edition of the Doctor Who Roleplaying Game from Cubicle 7.

Dalek battleship in high orbit around Tarack

Mass : 0.0106 x Earth ( 0.861 x Moon )

Diameter: 3,436 kilometres 

Density: 2.98 grammes per cubic centimetre

Average temperature: -35.4 degrees Celsius  (minimum -158 degrees Celsius, maximum -7.59 degrees Celsius)

Rotational Period: 7.88 days (tidally locked)

Orbital Period: 7.88 days

Surface gravity : 0.146 g

Semi-Major Axis of orbit around Galentor : 164,380 kilometres

Eccentricity of orbit : 0.0199

Inclination of orbit: 1.65 degrees

Obliquity : 2.29 degrees

Tarack is the sole natural moon of Galentor and one of the most visually arresting bodies in the Galen Alpha system. Though slightly smaller than Earth’s Moon, it is geologically far more active. Its deep red surface, streaked with darker lava plains and fractured highlands, makes it unmistakable from orbit and unforgettable in Galentor’s night sky.

There is no native life on Tarack. It is a world shaped by heat, stress and tidal strain. It is sometimes compared to Io, a moon of Jupiter in Earth's Solar System.

Formation and Early Evolution

Tarack most likely formed early in the history of the Galen Alpha system from debris placed into orbit around Galentor following a colossal impact event. Its relatively low density of 2.98 g/cm³ suggests a silicate-rich body with a modest iron core, consistent with differentiation during a molten early phase.

In its infancy Tarack orbited much closer to Galentor. Over time, tidal interactions transferred angular momentum from Galentor’s rotation into Tarack’s orbit, gradually pushing the moon outward to its present distance of approximately 164,000 kilometres.

Tarack’s orbital eccentricity is the residual outcome of its tidal evolution and the balance between internal energy dissipation and orbital circularisation. This small but persistent eccentricity is sufficient to generate ongoing tidal heating within its interior, which has led to huge changes over millions of years to the moon’s surface and a great deal of seismic and volcanic activity at present.

Orbit and Relationship with Galentor

Tarack orbits Galentor every 7.88 days and is tidally locked, always presenting the same hemisphere to its primary. Galentor’s rapid rotation period of 0.997 Earth days means Tarack rises and sets in the sky over the course of each Galentorian day, though its phase cycle spans the full 7.88-day orbital period.

From Galentor’s surface, Tarack appears immense. At a distance of roughly 164,000 kilometres and with a diameter of 3,436 kilometres, its apparent diameter is just over 1.1 degrees. This is more than twice the apparent size of Earth’s Moon as seen from Earth. It dominates the night sky and provides significant nocturnal illumination at full phase.

Its reddish coloration is clearly visible from Galentor without optical aid. At full phase it casts a faint copper glow across oceans and coastlines, giving rise to numerous cultural associations with fire, omens and endurance.

Tarack also exerts measurable tidal forces on Galentor’s oceans, contributing to pronounced tidal ranges in some coastal regions.

A small fraction of Tarack’s volcanic output does not fall back to its surface. During major eruptions, sulphur dioxide gas, sodium vapour and extremely fine dust can escape the moon’s weak gravity and become ionised by stellar radiation. Because Tarack orbits deep within Galentor’s magnetosphere, these charged particles are captured along magnetic field lines, forming a tenuous plasma torus along Tarack’s orbital path. 

Some of this ionised material is funnelled toward Galentor’s polar regions, where it enhances auroral activity, occasionally producing brighter and more complex displays than would otherwise occur. The total mass transferred is extremely small and environmentally insignificant at the surface, but in the upper atmosphere it creates a subtle and beautiful electromagnetic connection between the volcanic moon and the living world it orbits.

Tarack's orbit around Galentor

Internal Structure and Composition

Tarack is a differentiated rocky body composed of:

• A small iron-nickel core
• A thick silicate mantle
• A basaltic crust enriched in iron-bearing minerals

The red coloration visible from space is primarily due to iron oxides within its crustal rocks, especially hematite formed through oxidation of iron-rich basalts. Volcanic resurfacing has spread these materials widely across the moon.

Its mantle remains partially molten at depth. Although Tarack’s eccentricity is modest, the tidal forces exerted by Galentor are substantial because of the moon’s relatively close orbit. The resulting internal flexing generates steady tidal heating, estimated at perhaps half to two-thirds of Io’s heat flux. This makes Tarack one of the more geologically active rocky moons in its system despite lacking any outer resonant companion.

Surface and Major Features

From space, Tarack presents:

• Broad, dark basaltic plains formed by repeated lava flooding
• Massive shield volcanoes rising several kilometres high
• Extensive rift valleys and graben systems
• Large impact basins partially filled with younger lava flows
• Long tectonic scarps caused by tidal flexure

Unlike Io, Tarack lacks vivid sulphur deposits. Its palette is dominated by burnt reds, dark charcoal blacks and occasional brighter orange streaks where fresher lava has oxidised.

The surface is comparatively young in geological terms. Large ancient impact craters are present but often softened or partially buried by lava. Volcanic provinces cluster preferentially along zones of tidal stress, particularly near the equator and at longitudes facing and opposing Galentor.

If one were to stand on Tarack’s surface, gravity would feel extremely light at only 0.146 g. Movement would be slow and bounding. The terrain would be rugged and sharp, composed of fractured basalt, frozen lava channels and volcanic ash deposits. The horizon would appear relatively close due to Tarack’s small radius.

On the hemisphere facing Galentor, the primary world would hang in the sky, immense and blue-green, slowly rotating over the course of a Galentorian day.

Tidal Heating Mechanism

Tarack’s tidal heating arises from periodic distortion caused by its slightly elliptical orbit. As it moves closer to and farther from Galentor during each 7.88-day cycle, gravitational stresses flex its interior. This continual deformation generates frictional heating within the mantle.

Although the orbit is gradually evolving toward circularisation, the timescale for complete damping of eccentricity is long, potentially hundreds of millions of years. For the purposes of the present era, Tarack remains persistently active.

Volcanism

• Small to moderate lava effusions occur several times per year globally.
• Significant regional eruptions occur perhaps once every few decades.
• Lava is predominantly basaltic and highly fluid in low gravity, producing long, thin flows.
• Lava fountains may reach several kilometres in height.

Volcanic plumes are not as extreme as Io’s sulphur geysers, but they are dramatic by terrestrial standards. Thermal hotspots are visible from orbit.

Seismic Activity

Tarack experiences frequent tidal quakes.

• Minor quakes occur daily.
• Moderate magnitude five to six events occur several times per year.
• Larger magnitude seven events may occur once every few decades.

Because of the moon’s fractured crust and low gravity, seismic waves can reverberate for extended periods.

Tarack does not exhibit plate tectonics. Instead, it operates under a stagnant lid regime with crustal rifting and volcanic resurfacing acting as primary mechanisms for heat release.

Atmosphere and Climate

Tarack does not retain a substantial atmosphere. Its surface gravity is too low to hold one over geological timescales.

Instead, it possesses a tenuous exosphere composed of:

• Sulphur dioxide from volcanic outgassing
• Sodium and potassium vapour
• Trace carbon monoxide and carbon dioxide

Surface pressure is effectively negligible. There is no weather, no wind and no hydrological cycle.

Temperatures vary widely:

• Equatorial daytime highs may reach approximately −8°C under direct stellar illumination.
• Nighttime and polar regions can drop below −150°C.

The absence of an insulating atmosphere produces sharp thermal contrasts between sunlit and shadowed terrain.

Appearance from Space and Surface Perspective

From orbit, Tarack appears as a red volcanic world marbled with dark lava seas and intersected by pale tectonic scars. Occasional thermal glows mark active volcanic regions.

From Galentor’s surface, it is a dominant celestial presence more than twice the apparent size of Earth’s Moon. Its 7.88-day phase cycle produces dramatic crescents and striking eclipses.

From Tarack’s own surface, the sky is black even in daylight. Galentor looms vast and luminous on the near side, filling a substantial portion of the sky and displaying visible oceans, continents and cloud systems. Stars remain visible even during the day.

Long-Term Outlook

Tarack’s orbital eccentricity will slowly decline over very long timescales. As it does, tidal heating will gradually diminish. However, this process unfolds over hundreds of millions of years. For all practical historical and narrative timescales, Tarack remains a restless, volcanically active moon.

The TARDIS above Tarack, with Galentor in the distance

Galentor, natural garden world of the Galen Alpha System

This is a write up of Galentor, a planet in the Galen Alpha planetary system, and the main setting for the Tyranny of the Daleks scenario, using the Second Edition of the Doctor Who Roleplaying Game from Cubicle 7.

Galen Alpha c

Second Planet of the Galen Alpha system

Dalek shuttle leaving Galentor orbit

Mass : 0.94 x Earth

Diameter: 12,938 kilometres (equatorial)

Density: 4.95 grams per cubic centimetre

Average temperature: 24.6 degrees Celsius  (minimum -56.4 degrees Celsius, maximum 71.2 degrees Celsius)

Rotational Period: 0.997 days

Orbital Period: 11.8 months

Surface gravity : 0.913 g

Semi-Major Axis of orbit : 0.97 AU

Eccentricity of orbit : 0.0272

Inclination of orbit: 0.57 degrees

Obliquity : 7.57 degrees

Surface pressure : 107.9 Kpa at sea level

Atmosphere by volume:

76.45% nitrogen

22.5% oxygen

0.45% water vapour (varies)

0.42% argon

0.029% carbon dioxide

0.12% neon

0.02% hydrogen

0.003% methane

0.001% nitrous oxide

0.0008% krypton

0.0007% ozone

0.00009% xenon

0.005% trace biogenic organics

Introduction

Galentor is the living heart of the Galen Alpha system: a temperate, ocean-dominated world orbiting just inside the system’s classical habitable zone. It is the second planet out from the star Galen Alpha.IItWhere the inner planet Pentaurus is scorched and desiccated, and the outer giants loom in distant splendour, Galentor alone carries a fully developed biosphere and stable surface oceans. It is the natural focal point for exploration, diplomacy, and adventure. 

Galentor is widely regarded as one of the finest naturally occurring biospheres known to the Federal Empire. Earth, by the 42nd century, is a ruined world from centuries of overpopulation, destruction of natural ecosystems and climate change.  In comparison, Galentor is a pristine, beautiful wilderness and Xafonix, the planetary scientist leading its settlement, has proved conclusively that it is even more suited for life than Earth had been prior to the industrial period and the homeworld’s subsequent devastation by humanity.

To explorers and scientists alike, Galentor represents a paradox: a world of immense biological richness flourishing in one of the most isolated regions of the Milky Way, far from dense stellar nurseries, supernova shocks, or frequent cometary bombardment. It is a living archive of planetary and biological evolution, shaped more by time and internal processes than by external catastrophe.

Formation and place in the Galen Alpha System

Galentor formed approximately 3 billion years ago from the unusually massive and metal-enriched protoplanetary disc surrounding Galen Alpha. Despite the system’s remote location near the thinning edge of the Carina–Sagittarius Arm of the Milky Way Galaxy, the disc contained sufficient heavy elements to allow the formation of multiple rocky worlds.

Galentor accreted just beyond the inner volatile-loss zone, allowing it to retain substantial water and atmospheric gases while avoiding the intense early irradiation that stripped its inner neighbour, Pentaurus. Galentor is thus the second planet from Galen Alpha. From its earliest epochs, Galentor possessed shallow global oceans, a nitrogen-dominated atmosphere, and a magnetic field strong enough to protect its surface from stellar winds.

The planet’s low axial tilt, established early by the stabilising influence of its moon (covered elsewhere), prevented extreme seasonal cycles. Combined with Galen Alpha’s relatively subdued magnetic activity, this allowed Galentor’s climate to settle rapidly into a long-lived equilibrium.

Orbiting Galen Alpha at just under one astronomical unit, Galentor receives slightly more stellar energy than Earth does from Sol. Its parent star, Galen Alpha, is marginally more luminous than Earth’s Sun, yet Galentor’s modest orbital eccentricity keeps seasonal variations gentle rather than extreme. The world’s low axial tilt further moderates its climate, reducing harsh seasonal contrasts.

From the surface, Galen Alpha appears fractionally larger and brighter than Sol does from Earth. In the night sky, the volcanic moon Tarack dominates the heavens, a vast, slowly changing presence whose faint volcanic plumes can occasionally be detected as shimmering auroral distortions.

Galentor sits in a dynamically stable position within the system. The gas giants Volturn and Luradian shepherd the outer regions, preventing inward migration of debris and maintaining long-term orbital stability. The result is a mature, settled planetary environment some three billion years old.

Galentor’s orbit around Galen Alpha

Planetary Characteristics and Surface

Galentor is slightly lighter than Earth, with marginally lower surface gravity. Its diameter is similar to Earth’s, but its lower density reflects a somewhat smaller metallic core relative to mantle volume.

The surface is dominated by ocean. Approximately 74% of the planet is covered by interconnected oceans, leaving dispersed continents and archipelagos scattered across the globe. No single supercontinent exists. Instead, mid-sized landmasses and elongated island chains define the geography. 

Continental margins are complex and deeply indented, producing vast shallow seas and rich coastal ecosystems.  The coastal erosion occurring as a result increases environmental fertility by higher levels of mineral recycling into soils and shallow seas, leading to greater biodiversity.

This fragmented geography also promotes biodiversity by encouraging regional specialisation while maintaining global ecological connectivity.

Polar regions are largely oceanic. Permanent ice is rare and confined to isolated high mountain ranges. The planet’s warm equilibrium temperature and equable climate prevent large-scale glaciation.

Unlike many habitable planets, Galentor has avoided major global resets. There is no evidence of planet-wide glaciations or runaway greenhouse phases. Instead, the geological record shows a slow oscillation between warmer and cooler eras, with the present climate resembling Earth’s Eocene period: warm, humid, and biologically exuberant.

Atmosphere

Galentor’s atmosphere is breathable for humans without assistance, though slightly more humid on average than Earth’s. Nitrogen and oxygen dominate, with trace gases including argon and carbon dioxide. Water vapour plays an important climatic role, supporting a vigorous hydrological cycle.

The dense covering of most of the land masses with forests has produced an atmosphere with slightly higher levels of oxygen than is typical of Earth’s, and slightly lower levels of carbon dioxide, as more CO2 is fixed into the plant-like part of the biomass. This means the temperature is slightly lower than it would be if the atmosphere had the same composition as Earth’s.

Surface pressure is slightly higher than that of Earth at sea level, and the lower gravity makes movement feel subtly lighter without being disorienting. To humans arriving on Galentor, the atmosphere seems “deep” and invigorating, and over the decades, the settlers have adapted to it.

The sky is a deep blue under clear conditions. Cloud systems are prominent and dynamic, particularly over warm equatorial oceans. Storm systems are frequent but rarely catastrophic at continental scale.

Oceans

The oceans are the defining feature of Galentor. They are warm, extensive, and biologically productive. Continental shelves are broad, and shallow seas teem with life. Coral-analog reef systems flourish in tropical belts, forming labyrinthine archipelagos.

Deep ocean basins exist between continents, but the absence of polar ice caps ensures continuous circulation between equator and pole. Warm currents distribute heat efficiently, contributing to the planet’s globally mild climate.

Bioluminescent plankton blooms are common in certain regions, producing spectacular nocturnal displays visible even from orbit.

Tides on Galentor are higher than Earth’s, due to the closer proximity of its Moon. This leads to complex and rich intertidal zones, increasing biodiversity and leading to highly fertile deltas and estuary systems.

Two Dalek battleships in high orbit around Galentor, with a view of Tarack

Climate and Weather

Galentor’s climate can best be described as similar to that of Earth during its hottest period, the Eocene. It is warm, humid, and relatively equable. Average global temperatures are higher than pre-industrial Earth.

Seasonal shifts are mild due to low obliquity. Tropical and subtropical conditions extend well into higher latitudes. Polar regions experience cool temperate conditions rather than true polar cold.

The rotation period generates active atmospheric circulation. Mid-latitude cyclonic systems form regularly over ocean basins. Equatorial storm belts are persistent but stable. Hurricanes occur, but the planet’s high ocean coverage tends to dissipate their energy before they make prolonged landfall.

Lightning activity is frequent over warm seas. Auroral displays are common at high latitudes, occasionally enhanced by interactions between Galentor’s magnetosphere and volcanic ejecta from Tarack.

Geological and Tectonic Activity

Galentor is geologically alive. Plate tectonics are active, driven by internal heat from a still-warm mantle and moderate radiogenic decay, especially given Galentor’s younger age than Earth’s. Subduction zones ring several ocean basins. Volcanic island arcs dot tectonic boundaries, while high mountain chains rise where continental plates collide.

Seismic activity is frequent and persistent but generally moderate. The planet’s lower gravity produces slightly broader mountain profiles than Earth’s, with expansive plateaus and sweeping volcanic shields.  The regular activity sustains long-term carbon cycling. 

Hydrothermal vents in deep ocean trenches support complex chemosynthetic ecosystems.

The presence of plate tectonics contributes to long-term carbon cycling, stabilising atmospheric carbon dioxide and helping maintain climatic balance.

Biodiversity and Native Life

Galentor’s biosphere is ancient, rich and diverse. Life emerged early and diversified rapidly. There is no evidence of a single dominant extinction event or a succession of them as on Earth. Instead, evolutionary change has been gradual, layered, and cumulative.  Galentor's biosphere has been measured to be more productive and fertile than Earth's was at any point in its history.

Photosynthetic life dominates coastal shallows and inland wetlands. Vast marine ecosystems form the backbone of planetary productivity. Oxygen levels are high enough to support large, complex multicellular organisms.

Galentor’s plant analogues include vast forests of tall, branching organisms reminiscent of terrestrial trees, along with extensive fungal networks that permeate soils, coastlines, and shallow seabeds. These fungi-like life forms play a central role in nutrient cycling and symbiotic relationships.

On land, life has radiated into a variety of ecological niches. Forest-analogs extend into higher latitudes. Many terrestrial organisms exhibit lightweight skeletal structures, adapted to the planet’s slightly lower gravity.

Marine megafauna are particularly abundant. Some are even larger in scale than Earth’s great whales (all extinct by the 42nd century), though taxonomically unrelated. Marine ecosystems teem with complex organisms, including large, semi-intelligent predators and filter-feeders.  

Predatory aerial organisms thrive in the humid atmosphere, taking advantage of buoyant air and thermal currents.  Mammal-analogues roam the wide forests, including ferocious semi-bipedal carnivores. 

Palaentologists are puzzled by certain fossil finds that suggest intelligent animals may have arisen at several points in Galentor’s past, although no conclusions have been reached.  It is not thought that any intelligent Galentorian life forms were ever technological or industrial.

The long and undisturbed evolution of life on Galentor has led to rich and complex relationships developing at all levels, including phyla, kingdom and domain. These relationships include the parasitic, symbiotic and even altruistic. The Lentargi Field (see below) is believed to play a role in this highly interconnected biosphere. 

The Lentargi Field

Perhaps Galentor’s most mysterious feature is the Lentargi Field, a faint but measurable bioelectromagnetic phenomenon associated with certain living tissues, particularly advanced fungal networks, at deep ocean hydrothermal vents and neural structures of vertebrates.

The Lentargi Field is not a force in the conventional physical sense, nor does it violate known physics. Instead, it appears to be an emergent property of complex, interconnected biological systems operating at planetary scale. The field fluctuates subtly with ecological cycles, population density, and even planetary magnetic variations. Some introduced Earth species exhibit unusual adaptive responses when exposed to the Lentargi Field.

While its effects are weak, sensitive instrumentation suggests it may facilitate long-range biochemical signalling, enhance neural coherence, or subtly influence evolutionary pathways. Some Federation scientists speculate that the Lentargi Field may explain Galentor’s unusual ecological stability and resilience.

Others, such as Xafonix, believe it represents an early-stage planetary noosphere, a transitional phenomenon between purely biological life and something more profound. Federation xenobiologists have mapped correlations between Lentargi Field fluctuations and biological synchronisation events, but the underlying mechanism remains elusive and controversial. No consensus exists, and this unique field remains an active subject of debate and quiet fascination.

A World Apart

Galentor’s defining characteristic is not merely its habitability, but its continuity. Sheltered by distance and circumstance, it has evolved without the frequent cosmic interruptions that shape most life-bearing worlds. Its skies are dark at night, its star fields sparse, and its cosmic environment quiet.

To travellers arriving from crowded regions of the Galaxy, Galentor feels timeless. It is a world that has been allowed to become itself.

As Xafonix, Federation ecologist and biophysicist, famously remarked:

“Galentor is not just alive. It has been left alone long enough to understand what life wishes to be.”

Galentor seen from space

Pentaurus - Galen Alpha b - a planet in the Galen Alpha system

This is a write up of Pentaurus, a planet in the Galen Alpha planetary system, the setting for the Tyranny of the Daleks scenario, using the Second Edition of the Doctor Who Roleplaying Game from Cubicle 7.

Pentaurus, Galen Alpha b

Pentarus, first planet in orbit around Galen Alpha (the Athyric Rift is clearly visible in this photo)

Mass : 0.55 x Earth

Diameter: 10,242 kilometres

Density: 5.84 grams per cubic centimetre

Average temperature: 99.1 degrees Celsius (372 Kelvin) (minimum 1.64 degrees Celsius, maximum 123 degrees Celsius)

Rotational Period: 0.321 days

Orbital Period: 97.6 days

Surface gravity : 0.852 g

Semi-Major Axis of orbit : 0.42 AU

Eccentricity of orbit : 0.0139

Inclination of orbit: 1.10 degrees

Obliquity : 13.8 degrees

Pentaurus is the innermost planet of the Galen Alpha system, a scorched but enduring rocky world whose surface tells a story of lost oceans, planetary stress, and long, slow desiccation. Seen from orbit, Pentaurus presents a striking ochre and rust coloured globe, scarred by vast tectonic ruptures and mineral plains that glow faintly under the light of its parent star.

Appearance from Orbit

From space, Pentaurus is immediately recognisable by a colossal, planet spanning fracture zone that arcs across much of the visible hemisphere. This immense scar, kilometres deep in places, is believed to be the remnant of early global tectonic failure, possibly triggered by rapid internal cooling combined with tidal stresses during the system’s formative era. The fracture is not a single canyon, but a complex network of collapsed crust, rift valleys, and exposed mantle rock.

Surrounding this great rift are wide expanses of smoother terrain, coloured pale tan to deep ochre. These regions are interpreted as ancient seabeds and evaporite plains, where long vanished oceans once deposited thick layers of salts and fine sediments before retreating completely.

Scattered darker regions mark areas of denser basaltic crust or volcanic resurfacing, while lighter patches are consistent with salt flats and mineral precipitates, highly reflective and chemically altered by long exposure to stellar radiation.

Geological Character

Pentaurus is a dense, metal rich terrestrial planet, and its surface reflects a world that has endured enormous internal stress. Although large-scale volcanism has long since declined, geothermal activity remains present in isolated regions, particularly along tectonic boundaries and within deep canyon systems. Here, heat from the mantle still finds pathways to the surface, creating fumaroles, mineral vents, and occasional thermal outbursts.

The great fracture system visible from orbit still experiences minor seismic activity. These slow crustal movements periodically expose fresh rock faces and release trapped gases, contributing to the thin, chemically harsh atmosphere.

Climate and Environment

Pentaurus is hot, dry, and unforgiving. Its proximity to Galen Alpha results in strong solar heating, while its rapid rotation prevents extreme temperature locking between hemispheres. The planet experiences short, intense days and nights, producing strong thermal winds that carry fine mineral dust across the surface.

There is no stable surface water. However, mineral salts and hydrated compounds remain widespread, offering clear evidence of a wetter past. In low lying basins, transient brine films may briefly form under favourable conditions, evaporating quickly and leaving behind fresh crystalline deposits.

The atmosphere is thin and dominated by heavy gases, incapable of sustaining complex life on the surface. Nevertheless, the planet remains of great interest to scientists, as its crust preserves a remarkably clear record of planetary desiccation.

The Athyric Rift (also known as the Athyric Chasm Complex)

The vast canyon network visible across much of Pentaurus’s surface is known collectively as the Athyric Rift. Spanning nearly a quarter of the planet’s circumference, it is one of the largest continuous tectonic fracture systems known in the Galen Alpha system.

Origin and Formation

The Athyric Rift is believed to have formed during Pentaurus’s early cooling phase, when the planet’s dense metallic core contracted faster than its brittle outer crust. This contraction, combined with tidal stresses from Galen Alpha and the formative impact that created Calyx, caused the lithosphere to fail catastrophically along a global fault line.

Rather than forming a single canyon, the failure propagated laterally, producing a braided system of chasms, collapsed plateaus, and exposed mantle shelves. Some sections exceed 12 kilometres in depth, with stepped walls revealing clearly stratified mineral layers from Pentaurus’s oceanic era.

Physical Characteristics

The rift varies dramatically along its length:

• Primary chasm zones form sheer walled trenches hundreds of kilometres wide.
• Fracture fields consist of shattered crust, tilted slabs, and collapsed basins.
• Salt exposed terraces line many interior walls, glowing pale white or pink in orbital imagery.
• Dark thermal scars mark regions where mantle heat still rises close to the surface.
• In several locations, the canyon floor drops below what would once have been Pentaurus’s global sea level, strongly supporting the theory that ancient oceans drained into the Athyric Rift during the planet’s final desiccation phase.

Geothermal Activity

The Athyric Rift remains the most geologically active region on Pentaurus.

Isolated geothermal vents, mineral geysers, and superheated fumaroles dot the canyon floor and lower walls. These vents release sulphur compounds, metal vapours, and trace gases, creating shimmering heat plumes visible from orbit during favourable lighting.

Several of these regions are considered potential refugia for extremophile microbial life, sheltered from radiation and temperature extremes within mineral rich caverns.

Scientific and Exploratory Significance

For offworld researchers, the Athyric Rift is often described as a planetary autopsy laid bare. Its exposed layers provide a continuous geological record spanning more than two billion years. Ancient evaporite deposits preserve chemical signatures of Pentaurus’s lost oceans.

Seismic sensors placed along the rift detect slow, rhythmic crustal adjustments, suggesting the planet is still settling into long term equilibrium. The Rift’s complexity also makes it notoriously dangerous. Sudden rockfalls, ground collapse, and unpredictable thermal releases have claimed several AI probes.

Cultural and Narrative Notes

Among early Galen explorers, the Athyric Rift earned a grim reputation. Survey crews referred to it as “the planet’s open wound”, a phrase that later entered common astrogeological literature.

In some speculative xenohistorical theories, the Rift is believed to have influenced early life evolution on Pentaurus, acting as a final refuge zone as surface conditions deteriorated.

Secondary and Colloquial Names

Different traditions and organisations use alternate names for parts of the system:

The Worldscar – used by early deep space navigators.

The Ochre Divide – a poetic name referencing its colour contrast.

The Saltfall Trenches – used for regions rich in exposed evaporites.

The Calyx Line – a nickname among astronomers linking the rift’s origin to the moon forming impact.

A World of Narrative Significance

Pentaurus is not a dead world but a quietly active one. Its immense rift systems, salt deserts, and geothermal pockets make it an ideal setting for lost research stations, hidden subterranean installations, or ancient experiments abandoned when the planet’s habitability collapsed.

In the context of the Galen system, Pentaurus serves as a cautionary counterpoint to Galentor. Where Galentor flourished, Pentaurus endured. Its surface stands as a planetary fossil, preserving the moment when a world slipped just too close to its star and paid the price.

For travellers, Pentaurus is a place of stark beauty and deep time, a planet that invites exploration not for what lives there now, but for what once did, and what secrets still lie buried beneath its fractured crust.

Calyx

Calyx, the moon of Pentaurus

Mass : 0.0066 x Earth ( 0.536 x Moon )

Diameter: 3,318 kilometres

Density: 2.06 grams per cubic centimetre

Average temperature: 164 degrees Celsius (437 Kelvin) (minimum 136 degrees Celsius, maximum 167 degrees Celsius)

Rotational Period: 5.88 days

Orbital Period: 2.68 days

Surface gravity : 0.0975 g

Semi-Major Axis of orbit : 60,318 kilometres

Eccentricity of orbit : 0.0139

Inclination of orbit: 1.10 degrees

Obliquity : 151 degrees

Pentaurus is orbited by a single natural satellite, Calyx, a small but geologically distinctive moon that plays a subtle role in the planet’s long-term evolution.

Calyx is thought to have formed from debris generated by a major early impact on Pentaurus, an event that likely contributed to both the planet’s rapid loss of volatiles and the initiation of large-scale crustal fracturing that culminated in the Athyric Rift. Its composition supports this origin: Calyx is relatively low in density, with a mixed silicate and volatile-poor mantle, suggesting it accreted from already differentiated planetary material rather than forming independently.

The moon orbits unusually close to Pentaurus, completing a revolution in less than three days. Despite this proximity, its orbit is remarkably regular, with only a slight eccentricity and a low inclination relative to Pentaurus’s equatorial plane. Tidal interactions have long since locked Calyx into synchronous rotation, though its axial orientation is extreme. With an obliquity exceeding 150 degrees, Calyx effectively rotates in a retrograde, upside-down configuration, likely the lasting consequence of chaotic angular momentum transfer during its formation.

Calyx is intensely heated. Its surface temperatures are high even by inner-system standards, driven primarily by tidal stress and residual radiogenic heat rather than direct stellar illumination alone. While it lacks the violent volcanism seen on moons like Tarack elsewhere in the Galen system, Calyx exhibits widespread crustal deformation, extensive fracture fields, and regions of softened, partially molten rock beneath a brittle outer shell. Localised lava effusions and sulphur-rich deposits have been detected along major fault zones, particularly on the hemisphere facing Pentaurus.

The surface itself is pale, scorched, and uneven, marked by smooth plains of reworked impact material interspersed with uplifted ridges and collapsed basins. Few large craters remain intact, as surface renewal processes have erased much of the moon’s early bombardment record.

From Pentaurus’s surface, Calyx appears large and unsettlingly close, moving rapidly across the sky. Its pale, heat-blanched face reflects sunlight weakly, but during certain alignments it can be seen glowing faintly in the infrared, a visible reminder of the immense energies still at work within the inner Galen Alpha system.

Though Calyx is far too hostile to support life, it remains a world of great scientific interest. Its interior retains a thermal memory of Pentaurus’s violent youth, and continued study of the moon has yielded valuable insight into early planetary differentiation, tidal evolution, and the destabilising effects of close-orbit satellites in young stellar systems.

Calyx's orbit around Pentaurus

The Galen Alpha Planetary System

This is a write up of the Galen Alpha planetary system, the setting for the Tyranny of the Daleks scenario, using the Second Edition of the Doctor Who Roleplaying Game from Cubicle 7.

The Galen Alpha System

Overview

The Galen Alpha system is a rare and remarkable planetary arrangement found at the extreme fringe of the Milky Way. Orbiting a young, luminous G-type star in near-total isolation, the system has evolved with minimal external disturbance for over three billion years. Its architecture reflects both long-term stability and traces of ancient dynamical upheaval, shaped in part by the distant presence of its companion star, Galen Beta. At its heart lies Galentor, a fertile garden world whose biosphere has given rise to the enigmatic Lentargi field.

(References in what follows to an AU are to the Astronomical Unit, that is the distance from the Earth to the Sun, which is approximately 150 million kilometres, or 93 million miles.)

A view of the outer reaches of the Galen Alpha planetary system

The Star

Galen Alpha is a G1V main-sequence star with a mass of 1.04 times that of Sol and a luminosity 1.18 times greater. At an age of approximately 3.07 billion years, it is younger and slightly more energetic than Earth’s Sun, emitting a steady gold-white light with relatively subdued magnetic activity.

Its rotation period of 24 days and modest starspot cycle contribute to a calm stellar environment. Combined with the system’s isolation, this has allowed Galen Alpha’s planets to evolve without frequent radiation storms, nearby supernovae, or gravitational disruption. Galen Alpha is orbited at a vast distance of 0.542 light years by its faint companion, Galen Beta, forming one of the widest known stable binary systems.

Inner Dust Ring

A dust ring encircles Galen Alpha between approximately 0.15 and 0.28 AU, composed of hot silicates, carbon-rich grains and scattered metallic fragments.  This is the remnant of a population of early superheated planetesimals that failed to accrete.  

The Planets

The Galen Alpha system contains six major planets, arranged in a broadly classical architecture of inner terrestrials and outer gas giants, though with several distinctive features.

Pentaurus (Galen Alpha b)

A small, rocky inner world orbiting at 0.421 AU. Once partially oceanic, Pentaurus lost most of its volatiles early in the system’s history. It is now a dry, ochre-coloured planet marked by salt flats, deep canyon systems, and scattered geothermal regions.  This planet has one moon, Calyx, which probably originated from impact debris.

Galentor (Galen Alpha c)

The system’s primary life-bearing world, orbiting at 0.969 AU, mostly blue and shining from the oceans to be found on its surface. Galentor is a warm, stable garden planet with low axial tilt and shallow seasonal variation. Roughly three quarters of its surface is ocean, with small, widely distributed continents. Its biosphere is rich and extraordinarily interdependent, supporting forests, oceans, and complex life, including mammalian analogues. The Lentargi field is a planetary-scale bioelectromagnetic phenomenon emerging from this biosphere.

Galentor is orbited by Tarack, an Io-like volcanic moon whose intense activity is driven by tidal interactions within the system.

Karvtal (Galen Alpha d)

A cool, stormy terrestrial world at 1.34 AU. Karvtal is slightly larger than Earth, though less massive due to a lower density, with extensive cloud belts, glaciated regions, and active plate tectonics. Liquid water persists underneath the ice in equatorial, subterranean lakes, and microbial or primitive multicellular life is considered plausible. Karvtal possesses a single satellite, Velnara.

The Cyndor Belt (Inner Asteroid Belt)

The innermost of the Galen Alpha system’s two asteroid belts, this is found between 1.8 and 2.6 AU and is a wide, low-density asteroid region.  It is sparser than the asteroid belt in Earth’s Solar system, and has a low metallicity. 

Thandor (Galen Alpha e)

A cold super-Earth at 3.09 AU, with a mass 3.8 times that of Earth’s. Thandor is transitional between a massive terrestrial planet and a mini-Neptune. A thick ice shell overlies deep subsurface oceans, and a hydrogen-rich atmosphere blankets the surface. Its high obliquity drives extreme seasonal cycles. Thandor, uniquely in the Galen Alpha system, does not have a natural satellite.

Volturn (Galen Alpha f)

The inner gas giant, orbiting at 6.51 AU, and smaller and less massive than Jupiter. Volturn is a pale, mostly copper-coloured, storm-banded giant with a relatively low density and a rapid rotation period. Its early formation acted as a gravitational stabiliser, preventing inward planetary migration and contributing significantly to the long-term order of the system.

Volturn has a faint, pale ring system around it, and nine major moons, along with two small shepherd moons for the rings. It also has 43 inner moonlets, which are really piles of rubble between 1 and 50 kilometres across, and up to 400,000 kilometres distant in their orbit from Volturn.  Finally, there are 59 small moons of between 2 and 80 kilometres across at high inclinations and eccentricities with orbits beyond 1 million kilometres from Volturn, all of which are again little more than piles of rubble bound together with a loose covering of regolith.

Luradian (Galen Alpha g)

The outer gas giant, orbiting at 11.4 AU, slightly longer than the orbit of Saturn around Sol. Larger but less dense than Volturn (and indeed Jupiter), Luradian possesses an extensive and spectacular axial ring system, tilted at 52 degrees, and a dynamically complex moon family, including captured objects and active icy moons. Luradian is subtly coloured, with cyan and pink banding of clouds across its surface. 

Luradian has eleven major moons.  Two of the major moons act as shepherd moons for the ring system, along with seven moonlets embedded in the densest part of the ring, which create wakes and transient spokes during magnetospheric storms.  In addition, a captured icy dwarf planet orbits Luradian at the leading L4 point about Luradian.  Finally there are 58 small irregular moonlets in high inclinations and eccentricities beyond the orbit of the furthest major moon, Vaelor.  These moonlets are from 1 to 40 kilometres across, essentially piles of rubble bound by a loose and thin covering of regolith.  

The Outer Halin Belt

The outermost of the system’s two asteroid belts, this lies between 14 and 22 AU and is a thin, widely spaced belt of icy remains.  It was sculpted by early interactions between Galen Alpha and Beta before the latter was flung far out to 0.542 light years.

Far Objects Zone

Between 30 to 80 AU from Galen Alpha, this sparse and widely spaced zone includes a number of dwarf planets, extremely scattered objects and dormant comet nuclei.  It has a very low density but is deeply ancient compared to the rest of the system.  One body, provisionally named Xyr, displays anomalous spectral lines possibly related to the Lentargi field.

Interactions with the Galen Beta System and Interstellar Space

Galen Beta’s distant orbit has had no significant effect on the stability of Galen Alpha’s planets in the present era. However, early interactions likely shaped the outer debris structures and cleared much of the primordial material beyond the gas giants.

The system’s position at the edge of the galactic disk places it in an exceptionally sparse stellar environment. With no nearby stars, nebulae, or supernova remnants, Galen Alpha has evolved in near isolation. This cosmic quiet has preserved its planetary architecture and allowed Galentor’s biosphere to flourish uninterrupted for billions of years.

To Federation astronomers, the Galen Alpha system stands as a rare natural laboratory. A complete, life-bearing planetary system formed and matured at the very edge of the Galaxy, far from the turbulence of its crowded heart.

The inner Galen Alpha planetary system

GALEN BETA - M9V Red Dwarf Companion of the Galen System

A write-up of the Galen Beta system from Tyranny of the Daleks.  This is for the second edition rules for the Doctor Who Roleplaying Game from Cubicle 7.

Galen Beta is the faint, compact, and ancient-seeming red dwarf companion to Galen Alpha. Although both stars formed together, Beta matured into one of the smallest possible true stars, shining only faintly in the deep interstellar dark far beyond the crowded spiral arms. Its remote orbit, extreme stellar density, and austere planetary system make it one of the strangest known systems in this region of space.

Galen Beta, seen at a distance of around 500,000 kilometres and in the distance Lethion at around 1.4 AU, and Galen Alpha about half a light year away

Spectral type: M9V main-sequence star

Mass: 83.3 x Jupiter or 0.0795 Solar mass

Radius: 1.18 x Jupiter (86,500 kilometres)

Density: 67.2 g/cm3 (Fifty times that of Jupiter)

Luminosity: 5.15 x 10-4 x Sol

Surface temperature: 2500 K

Age: 3.07 billion years

Rotation period: 15.1 days

Distance from Galen Alpha: 0.542 light years (semi-major axis)

Orbital period around Galen Alpha: 5,980,000 years

Surface Gravity: 1.48 km/s2 (roughly 150 times the surface gravity of Earth)

Obliquity: 14.3 degrees to orbital plane

Orbital Eccentricity: 0.345

Orbital Inclination: 12.2 degrees

Galen Beta represents the practical minimum mass at which hydrogen fusion can occur. Its radius barely exceeds that of Jupiter, but its density is fifty times that of the gas giant, reflecting the intense compression of matter in the lowest mass main-sequence stars.

Despite its small size, it is a fully fledged star. Its faint light is a deep ruby red, and its luminosity is only five ten-thousandths that of Earth’s Sun. Even planets in close orbits receive very little energy, creating a cold and unwelcoming system.  Most of its radiation is in the infra-red rather than visible light.

Formation

Galen Beta formed from the same primordial cloud that created Galen Alpha, but the environment in this sparse region of the galaxy slowed star formation considerably. The initial material was thin and irregular, producing two protostars with very uneven masses. Galen Beta was deprived of much of its potential accretion by the rapidly growing Galen Alpha, which absorbed most of the available matter from the shared protoplanetary disc.

Beta therefore emerged as a borderline red dwarf that very nearly became a brown dwarf. The early gravitational interactions between the two forming stars sculpted and disrupted the material around them, leaving Galen Alpha with a much richer planetary system and Galen Beta with only a small inner disc of debris from which a handful of close-orbiting planets later condensed.

It is believed that Galen Beta originally formed much closer to Galen Alpha and then following formation, its orbit increased slowly over millions of years to the far range that it has now. This movement affected the development of Galen Alpha’s planetary system.

Because the two stars orbit at great distance, tidal effects after formation have been negligible. Galen Beta’s eccentric orbit through the deep interstellar medium has, however, gently perturbed the outer debris populations of both systems over billions of years.

The Galen Beta Planetary System

Galen Beta possesses a small, compact but scientifically fascinating planetary system consisting of three terrestrial-class planets (one of which is a super-Earth) and one mini-Neptune, all orbiting close to the star. The outermost planet, the gaseous mini-Neptune named Lethion, orbits Galen Beta at a distance of approximately 1.4 AU, roughly the same distance as Mars does Sol.  All Beta-worlds are extremely cold due to the star’s minuscule luminosity.

Beyond the planets lies a broad and sparse cold debris belt from roughly 2.2 to 6 AU, a remnant of early disc fragmentation and later sculpting by the distant gravitational influence of Galen Alpha. The belt is extremely cold and sparsely populated. It acts as a long-term reservoir for cometary bodies that occasionally wander inward over multi-million-year cycles.

The Galen Beta planetary system, including the two terrestrial planets Eryndra and Kelthar nearest the star, the super-Earth Dravis and the mini-Neptune gas planet Lethion.

Appearance from Galentor

From Galentor, Galen Beta shines as a faint red star on clear nights, unusually bright for its color but far dimmer than any of the visible planets. It never rivals the brilliance of Earth’s Mars or Jupiter but stands out by hue alone. Under ideal conditions it can even cast the slightest hint of red-shifted illumination on reflective surfaces, though this is subtle and easily missed.

Galen Beta is not a placid ember. Its rotation is slow enough that it is not in the continuously furious category of flare stars, yet fast enough to sustain a vigorous magnetic engine. Observatories detect a steady hum of X-ray flicker and a profusion of starspots that slowly march across the face of the star as it turns. The heavens over a Beta planet are often alive with sudden red-white flares and green auroral curtains that leap when a particle storm hits.

Its slow-motion orbit ensures that its position in Galentor’s sky changes only over geological timescales. To the inhabitants, Beta is a constant ember burning on the edge of the night.

Galen Alpha: The Heart of a Forgotten System

A write-up of the star Galen Alpha, part of the setting for Tyranny of the Daleks.  This is for the Doctor Who Roleplaying Game from Cubicle 7.

Designation: Galen Alpha

Spectral Type: G1V main-sequence star

Mass: 1.04 × Sol

Radius: 1.07 × Sol

Luminosity: 1.18 × Sol

Surface Temperature: 5820 K

Age: 3.07 billion years

Rotation Period: 24.0 days

Distance from Galen Beta: 0.542 light-years

Surface Gravity: 0.249 km/s²

Core Temperature: 15.3 million K

Galen Alpha, with Galen Beta visible about half a light year distant. Also shown are the orbits of some of Galen Alpha's planets

Overview

Galen Alpha is a sun of quiet majesty, a G1V main-sequence star burning with a steady gold-white radiance similar to Earth’s own Sun. At 1.04 solar masses and 1.18 times its luminosity, it is just slightly more powerful and somewhat younger than Sol, a warm and vigorous stellar engine nearing the midpoint of its life. Yet, unlike humanity’s familiar star, Galen Alpha shines across an interstellar void almost devoid of neighbours, in one of the Galaxy’s most remote and tranquil regions.

Orbiting serenely in this isolation, Galen Alpha and its distant companion, the faint red dwarf Galen Beta, form a binary system whose gravitational bond stretches across half a light-year, making it one of the widest stable stellar pairings known to the Galactic Federation. Their lonely partnership defines the Galen System, a rare island of light in a sea of cosmic darkness.

Origins of the Galen System

The Galen System lies within the Thayrn Assemblage, a small and isolated group of only nine stars scattered across a fifty light year radius at or rather beyond the remote end of the Carina–Sagittarius arm, on the far side of the galaxy from Earth's Solar System. Beyond this pocket of stars, space becomes extraordinarily empty: the nearest other systems lie at least sixty light years farther out towards the last reaches of the spiral arm, and even these are themselves lonely outposts on the thinning edge of the galactic disk. The interstellar medium in this region is exceptionally sparse, making the existence of any star cluster here a surprising anomaly.

After the Milky Way settled into its mature form billions of years ago, the galactic frontier where the Thayrn Assemblage now resides contained only a thin, diffuse cloud of hydrogen. The material was so insubstantial that no substantial molecular clouds formed, and therefore no stars. For around a billion years, this region remained dark and entirely empty.

Around eleven billion years ago, a large galaxy known as “Kraken” was drawn into the Milky Way and disrupted in a collision between the two galaxies. Tidal forces from the crash scattered streams of stars and dust throughout the outer halo, including into this far-flung sector. For the first time, heavier elements, including some exotic molecular forms uncommon in the inner Galaxy, drifted into the region. Though this enrichment raised the metallicity slightly, the density was still far too low for star formation.

The decisive moment came much later. Roughly 3.5 billion years ago, the shock front of a distant gamma-ray burst swept through the remote outskirts of the Carina–Sagittarius arm. Though the GRB itself had occurred many thousands of light years away, far enough not to sterilise worlds, its pressure wave pushed additional enriched material into this frontier, compressing the interstellar medium into higher-density pockets.

One such pocket collapsed into a molecular cloud around a hundred light years across. Compared to the great star-forming complexes near the galactic centre, this cloud was thin and inefficient, but it was dense enough to ignite a brief and localised episode of star birth.

This triggered collapse formed a small handful of protostars in a compact region at the cloud’s centre. Because they formed together and possessed nearly identical initial velocities, they have remained loosely associated ever since, a fragile cluster adrift at the galaxy’s edge. These stars became the Thayrn Assemblage.

Among them were Galen Alpha and its low-mass companion Galen Beta.

Some of these protostars retained protoplanetary discs; Galen Alpha’s disc was unusually massive for such a remote environment. From it formed a rich and diverse planetary system, including the garden world Galentor (Galen Alpha II).

Stellar Character and Behaviour

Spectroscopically classified as G1V, Galen Alpha’s light falls midway between the warm yellow of Sol and the paler hue of an F-type star. Its photosphere burns at 5820 Kelvin, giving the star a faintly whiter cast than the Sun when viewed directly through a filtered optical array. The stellar surface seethes with granulation and slow convection, driving a cycle of magnetism and solar weather that is relatively gentle compared to younger or more active stars.

Federation spectroheliographs have revealed a periodicity in its starspot cycles of approximately 8.9 years, shorter and less intense than Sol’s eleven-year rhythm. This subdued magnetic activity, combined with the system’s extreme isolation, contributes to the remarkable climatic stability of Galen Alpha II (Galentor), the system’s fertile, life-bearing world.

At its core, Galen Alpha sustains hydrogen fusion at 15.3 million Kelvin, producing a luminosity 18% greater than Sol’s. This mild excess of energy places Galentor in a slightly wider orbital band than Earth but still within the comfortable limits of a temperate biosphere.

The Binary Bond

The companion star, Galen Beta, lies at the extraordinary distance of around half a light year,  a separation of around 34,000 astronomical units. A dim red dwarf, one of the smallest found in the Galactic Federation, it circles its larger sibling in an orbital period measured not in centuries but in millennia. Despite this, the two remain gravitationally bound, their motions locked in an elegant celestial dance that has endured since the system’s birth.

Astronomers speculate that Galen Alpha and Beta formed together from the same protostellar cloud, but that an early interaction with a passing interstellar body flung Beta into its current distant orbit. Its gravitational influence has profoundly shaped the system’s structure, sweeping clean the outer debris and sculpting the cometary reservoirs into fragile shells.  Their enormous distance as a binary star means that the presence of Galen Beta makes no discernible difference to Galen Alpha’s planetary system of ten principal planets, numerous moons, comets and asteroids.

Scientific Significance

Galen Alpha’s moderate metallicity, albeit rather lower than that of Sol, offers insights into star formation at the extreme rim of the Milky Way. Its composition indicates that the heavy elements required for planet formation were still relatively abundant in this region three and a half billion years ago, implying earlier episodes of stellar generation farther inward in the Galaxy had already seeded this frontier with the materials of life.

For astrophysicists, the Galen system is thus a paradox: a cradle of planetary richness located in one of the most barren sectors of the Galaxy. How such a system formed and survived so far from the spiral arms remains one of the great puzzles of deep-space astronomy.

A Beacon at the Edge

Seen from afar, Galen Alpha burns like a solitary lantern suspended over a dark ocean, a symbol of endurance and constancy at the farthest limits of the Milky Way. To the explorers and settlers who have crossed the void to reach it, it represents both refuge and reminder: that even at the edge of the known, light persists.

The Galen system - an overview

The adventure “Tyranny of the Daleks” is set in a binary star system, known as Galen.  The larger of the two stars is Galen Alpha, a main sequence G1V spectrum star. It is orbited by Galen Beta, a red dwarf star. The Galen system is at the absolute tail end (and possibly beyond that) of the Carina-Sagittarius arm of the Galaxy, in practical terms on the other side of the galaxy from the Sol System and about as far away from Sol as it is possible to be without leaving the galaxy, at around 75,000 light years distant.  It is approximately 30 light years below the galactic plane. 

The interstellar region around the Galen system is rather empty, and the nearest star is roughly 27 light years away.  This has resulted in the Galen system being entirely overlooked and untouched by any external influence until the arrival of the Federation long range scientific vessel, the F.S.S. Thomas Stafford in 3827, which spent six months mapping it in outline in a preliminary reconnaissance mission before returning to its base of operations at the F.S.B. Lovell Deep-Space Observatory in the Yedrax Cluster.

Galen Beta has a relatively large and surprisingly circular orbit. Ordinarily the orbit of Galen Beta should, according to mathematical modelling, be where the Oort Cloud for Galen Alpha would be but Galen Beta has effectively swept away the protoplanetary disc of material. This configuration has shaped the distribution of matter in the system, suppressing the formation of additional terrestrial planets close to the primary star and creating a distinctive pattern of cometary and minor body orbits.

The position of the Galen System in the Milky Way

The Galen Alpha planetary system consists of six principal bodies, those being three terrestrial planets, a super-Earth and two relatively small Jovian gas giants. There are also two thin asteroid belts, and an outer cloud of dwarf planets, dust and debris. Galen Alpha II, known as Galentor, is a fertile garden world, hosting a young and energetic biosphere. This is a surprisingly diverse and rich planetary system for a star so far out from the galactic core.

The Galen Beta planetary system is much less substantial, consisting only of two small sub-Neptunians, each with its own system of satellites. None are considered suitable for settlement without substantial terra-forming. Galen Beta itself is considered to be a failed main sequence star and without the consumption of Galen Alpha's protoplanetary material may well have concluded at the brown dwarf stage.

The region around the Galen System is extremely sparsely populated. Within a 50-light-year radius, there are only a handful of known stars. There are no large open clusters or prominent nebulae in the immediate vicinity, and the galactic background density of stars is significantly lower than nearer to the galactic core. This isolation has contributed to the relatively undisturbed development of Galen Alpha II, Galentor, with minimal external influences such as supernova shockwaves or heavy interstellar radiation flux.

Interstellar travel in this region is further complicated by the low frequency of navigational landmarks. The four nearest known systems are:

• Virellon System, 27 light-years from the Galen System, a pale blue-white F-type star illuminating a scattered belt of crystalline asteroids. Old Federation deep-space probes once detected strange harmonic radio emissions from within the Virellon Belt, never explained, and now long forgotten. Local legends speak of “the Singing Stones of Virellon.”

• Orrath System, approximately 32 light-years distant, a dim K-class subgiant surrounded by drifting remnants of a once-massive gas giant, destroyed in an unknown cataclysm. Its sole surviving world, Orrath IV, known as Olyrra, supports vast fungal plains that glow faintly in darkness, bioluminescent ecosystems linked by chemical communication across continents, which are reminiscent of organic forms found on Galentor.

• Thyraxis System, 34 light-years away, notable for its bright K-type main-sequence star and a wide circumstellar ring of debris thought to be the remnants of a failed planetary system.

• Yedrax Cluster, 41 light-years distant; a small, tightly bound group of four K- and M-class stars with a rich circumstellar medium. It hosts the F.S.B. Lovell Deep-Space Observatory, a Federal Empire station dedicated to exploration, scientific observation, and long-range surveys of outer galactic space and indeed intergalactic space. The Yedrax Cluster is becoming a key forward outpost for monitoring interstellar phenomena and emerging threats to Federal Empire space.

This small grouping of stars makes up the closest this part of the galaxy has to a cluster or a stellar association, and is known as the Tharyn Assemblage, after Professor Vek Tharyn, the Draconian astrophysicist who formed part of Doctor Xafonix’s team.  Professor Vek Tharyn discovered that this small grouping of stars is found within a localised region centred on the Thryaxis System, roughly spherical in shape and 50 light years in radius, which is denser than the surrounding very thin interstellar medium this far out from the galactic core.

Beyond this localised density of the interstellar medium, space in these far reaches of the galaxy is very thin and the interstellar medium here is much less dense than that around Earth’s Solar System.  The Galen system is some 5,000 light years from the effective edge of the stellar disk of the galaxy, that is the part of the galaxy containing the spiral arms and their stars.

The Galen System is effectively a cosmic island, where phenomena such as interstellar cloud encounters, nearby supernovae, or perturbations from stellar neighbours are rare, making it one of the quietest and most stable sectors for long-term planetary evolution. This isolation has aided the stability of Galentor’s biosphere, leading to an extraordinarily interdependent ecosystem.

Prior to the inauguration of the Galactic Federation, the whole region in which the Tharyn Assemblage is found was claimed by the Draconian Empire, although during this period it was never explored or even reached.  

In practical terms, Galen’s location at the very edge of the galaxy means that exploration and supply missions from the Galactic Federation or Federal Empire were always going to be infrequent and extremely delayed, giving any settlers a degree of autonomy uncommon in more densely populated regions of the Milky Way.

Galen Beta's orbit around Galen Alpha and its planetary system. The orbit of Falcoris around Galen Alpha is just about visible in this image.