Endor Holocaust

What happens when you detonate a spherical metal honeycomb over five hundred miles wide just above the atmosphere of a habitable world? Regardless of specifics, the world won't remain habitable for long.


This document does not advocate or condone the extinction or betrayal of ewoks, it merely reports upon a physical situation and the acts involved.

The circumstances at the end of Return of the Jedi lead inevitably to an environmental disaster on the Endor moon. The explosion of a small artificial moon in low orbit sends a meteoric rain onto the ewok sanctuary, on a scale unmatched since Endor formed. Through either direct atmospheric injection of small particles, or showers of ejecta from large impacts, the atmosphere will be filled with smoke and fallout causing a gargantuan nuclear-winter effect.

Unless the rebel commandoes on Endor were executing a suicide mission, the rebel fleet was evidently able to intervene to protect their immediate vicinity: probably an area comparable to Luxembourg. Debris fragments amounting to the mass of the rebel fleet might conceivably have been diverted from that particular locality (by the exertion of the fleet's tractor beams) and onto adjacent areas of the Endorian globe. However this is only a tiny fraction of the total mass incident on the moon during an event lasting mere minutes. The mass of the entire debris cloud and fireball is incomparably (inexorably) greater than the combined mass of both fleets over Endor.

A general climatological catastrophe was unavoidable. Averting the disaster would have required physical action on a scale greater than the construction of a Death Star, within minutes of the battle station's explosion.

Immediately following ROTJ the Endor moon has become unliveable, meaning that the ewoks are extinct except for those:

This page is not concerned with environmental amelioration. The New Republic, former-Imperial warlords, the Svivreni or galactic conservationists could make attempts to terraform and repair the moon, but these are long-term measures and cannot stop the immediate damage that occurs within minutes and hours of the explosion. The scope of galactic technology is not great enough to magically restore ecosystems buried beneath dozens of metres of metallic dust or debris, nor resurrect life forms smothered by a chemically-altered atmosphere. Artificial structures, like the urban terrain of Coruscant after Dark Empire, can be replaced or restored globally in a year-long rebuilding project that is comparable to the construction of a Death Star. However trees and living systems are no so quick to restore. At the very least, if all the Endorian species were preserved off-world, the replanted forests would take decades to grow. In any case, amelioration and restoration projects, and the motives of whoever implements them, are in the realm of speculation. The biotic catastrophe itself is a well founded and direct consequence of the observable events of the STAR WARS canon. That is the basis of the discussion below.


Thanks are due to, in alphabetic order:

Artificial Disaster

The Death Star II was designed as bait for the Rebel Alliance, but it was never supposed to be destroyed. The station was meant to be protected by an impenetrable deflector shield. Primitive bipeds on that paradise world were recruited and exploited by daring rebel commandos. They managed to overwhelm the security forces defending the shield's power generator. Ironically, the ewoks were actually the beneficiaries of the deflector shield, and their aggression indirectly and unwittingly brought about their world's doom.

Destruction of both the deflector shield and the battle station caused some serious collateral damage.1


The technical principles underlying power systems in STAR WARS technology are not fully clear to us. "hypermatter" annihilation is the main and ultimate power source for large warships and battle stations [SW:ICS p.10, AOTC:ICS p.5], however nuclear fusion and antimatter annihilation play a subsidiary or secondary role. For all we know, they may also employ more exotic and potent technologies: perhaps tapping into deeper subatomic realms, portable miniature black holes or other phenomena unfamiliar to Earthly engineers. We know that hypermatter involves supralight particles [AOTC:ICS p.5], and we can infer that its annihilation produces radiant decay products like antimatter annihilation or nuclear reactions do. The mass/energy conversion of hypermatter must be as complete and as practically effective as antimatter annihilation, otherwise the latter would have been used instead.

The destructive magnitude of the superlaser implies power systems of vast power and admirable efficiency. The main reactor core of the Death Star II was a machine of immense scale operating on what probably were post-nuclear technological schemes. As a general tendency of human works, the deeper the technology, the worse may be the by-products of its uncontrolled failure: disasters of pre-nuclear technology produce poisons or fires; nuclear explosions leave abundant radioactivity; the detonation of a Death Star could be at least as dirty. But we don't know for certain.

Even if exploding hypermatter power sources are completely clean, the subsidiary antimatter and fusion devices in the Death Star II must have created an enormous burst of gamma-rays and high-energy particles. [Meltdowns are mentioned in ROTJ novel, chapter 9.] The magnitude of this flash is difficult to assess without intimate knowledge of the superphysical mechanisms of the runaway reaction and the evolving gamma-ray opacity of the debris cloud, but at least the outermost layers of the explosion must have emitted high-energy by-products. The visible parts of the surface of the nearby moon, which was as near as two thousand kilometres at the closest point, amount to 5/36 of the total area and must have been bathed in radiation. Living organisms on the irradiated side of the moon would be disposed to radiation sicknesses, if not sterilised or killed outright. Lingering radioactivity from affected areas of the moon's surface and radioactive debris fallen from the battle station would be a perpetual hazzard. Although the specifics are hard to estimate, the initial radiation flash and the long-term contamination may actually be more deadly than the climatological damage described below.

Orbital considerations

The Death Star II was in a very low orbit. According to geometric studies, the construction site was at an altitude which put its orbit within a double-radius of the moon's centre. A likely estimate for the moon's radius is 5200km, based on the surface gravity and realistic ranges of planetary composition. Assuming this scale, the orbital geometry is such that the battle station is only another 2000km above the surface.

The Death Star II remained stationary above the surface facility which generated its protective shield. In order to remain synchronous with the surface, the station's orbital period needed to exactly match the duration of the Endorian day2. However for all plausible ranges of the moon's composition, the orbital period will be very short for any object in a free orbit at this level. It should circle the globe in only a few hours.

There is good reason to believe that the moon does not have such a short rotation period. If the day was so short then the shadows would be move visibly during scenes, and the globe would be rotationally distorted. In other words the moon would have a noticeably oblate aspect, with the diameter through the poles being visibly narrower than the diameter through the equator. The observed profile of the moon is a nearly perfect sphere.

Therefore an object moving at the altitude of the Death Star II and which also has a period slow enough to be synchronised with the moon's rotation cannot be in a free natural orbit. In other words, the battle station was moving around the moon too slowly and with insufficient energy to stay up by itself. It needs supplementary support against gravity or else it will literally fall from the sky. The Death Star II therefore possessed an artificial support mechanism.

This mechanism could not have been the simple kinetic action of the station's sublight thrusters, since they would lead to either an increased orbital distance or increased rate of orbital revolution. Even in the last few minutes of the station's existence, it would have visibly moved away from its position above the location of the rebel strike team. As seen by the rebels, it would have moved close to or over the horizon. (Moving to the horizon would involve only about a tenth of a free orbit. A free orbit at that altitude is only a couple of hours long; hence only about a dozen minutes are needed to reach the horizon.)

The support was most likely provided by a large-scale repulsor field projected along with the security shield, generated at the surface facility. Alternatively, repulsors may have been mounted within the shell of the station itself. This seems most likely, since the station did not immediately fall out of the sky after the ground facility was obliterated.

In any case, the repulsors were destroyed either when the shield facility was demolished or when the station itself exploded. The artificial orbital equilibrium was broken and the remains of the Death Star II would drop into moon's atmosphere within only a few minutes, even if it were not already exploding in all directions (including the direction towards the moon).

Death Star II hangs serenely in low orbit above the sanctuary moon.

The surface facility generating the security deflector shield might also have been responsible for a repulsor field which supported the station vertically.

Debris influx

What happens next depends on the explosion's energy and the distribution of the sizes of the debris particles. There are two extreme cases according to the explosive energy of the battle station's destruction; these tell us that the total amount of material reaching the moon is somewhere between a sixth the station's mass and all of the station's mass.

Careful timing measurements indicate that the outer surface of the fireball expands at about 80 km/s. Matter hidden below the surface expands at the same or slightly lower velocity.

The mysterious flaming ring emerging from the equator was much faster, but until more is known about its composition we cannot assess its environmental impact. It could be intangible.

At least thirty multi-kilometre solid chunks emerged from and overtook the roiling debris cloud. Their velocities are greater than the 80km/s of the cloud's general expansion. (In fact there were enough large pieces of debris that Shug Ninx was able to purchase a mile-long piece of salvaged air-shaft, as shown in Dark Empire and Dark Empire Sourcebook.)

Escape velocity at the Death Star's altitude is on the order of 7km/s (assuming a realistic estimate for the moon's mass and composition). Since all major visible components of the explosion were moving dozens of times faster, the explosion was of the hard type.

It has been asked whether the total mass of the battle station's remains was great enough so that the fireball could fall back inwards upon itself due to self-gravity, perhaps to be swallowed by whatever exotic residue the reactor core may have left. Unfortunately, if this were the case, the outward motion of the margins of the fireball would have slowed visibly during the time shown in the movie. Empirically, it did not. Furthermore, Princess Leia did not encounter any self-collapsed remnant when she visited the place where the station would have been five years later, in Dark Force Rising. In any case, the mass needed for self-collapse would have been much greater than that of the Endor moon itself, and the station's everyday tidal effect would have warped the moon's shape noticeably.

Having established that millions of cubic miles of porous metal3 will inevitably strike the atmosphere, it is important to consider the state of the debris:

When there are significant impact events, the total amount of atmospheric dust will be greater than merely the mass of all the impactors. Large impacts yield more dust as ejecta (pulverised rock from the crater) than from the body of the projectile itself. Impacts will also kindle forest fires of global scale, sending further soot into the air. (Endor's isolated, unconnected seas cannot interrupt such fires; the burning will be much more extensive than during similar calamities on Earth.)

Observations of the morphology and kinematics of the explosion suggest that a combination of fine and coarse effects were experienced. The larger pieces are representated by at least fourteen fragments each a few tens of kilometres wide, seen hurtling down towards the moon's atmosphere. An explosive ring of plasma, erupting from the battle station's equator, will strike the moon within seconds, though it is unknown how much actual substance this phenomenon contains. The rest of the debris lacks discernable structure and seems to be fine.

The apparent tranquility of the site around the demolished shield generator, where the rebel commandoes celebrated their victory, has implications for the size distribution of the debris particles. The debris chunks which would have directly collided with the ground team must have been deflected to other areas of the moon's surface by the screening rebel fleet. However an impact over a certain size will cause a rain of ejecta and seismic concussion which would have harmed the commandoes even if they were dozens, hundreds or even thousands of kilometres away. This suggests that apart from the fourteen or so visibly large fragments, most of the impacting debris comprised bodies no larger than a dozens or a few hundred metres across, whose impacts would have no more effect on the rest of the globe than thermonuclear detonations. Much of the mass of the battle station probably fell as centimetre-sized or smaller grains, burning in the air and directly entering the atmosphere as dust without striking ground.

The nett result in all scenarios is that a huge volume of dust is left high in the upper atmosphere. The total amount is equivalent to the mass of a porous lump of metal several hundred miles wide, plus whatever enhancement is derived from impact ejecta. If the remains of the Death Star II were evenly laid upon the moon with the same density as in the original substance of the station itself (with no extra compaction) then the entire globe would be buried in a wreckage layer over half a kilometre deep. Of course, significant compaction is likely; the final depth of solid material is likely to be only a few dozen metres on average. The sanctuary moon of Endor is likely to resemble a heaven for junk scavengers.

Even if it were not for dust-induced climate shifts, the chemistry of the air and surface of the moon must be severely changed by the arrival of this immense mass of foreign material. The debris is likely to include noxious chemicals similar to those which sterilised most of Honoghr.

The far side of the moon would not receive many direct hits. A minor fraction of the debris might be moving slowly enough to follow trajectory/orbits leading to collisions with the moon's opposite face. Some big impacts on the forward face of the moon may produce secondary debris that would fly into low orbits and then land on the far side, but on the whole the far side should fare better than the side that is directly under the explosion. However the most serious effects such as global firestorms, chemical contamination and the "nuclear winter effect" will be carried around the world by regular atmospheric circulation.

[Death Star II and Endor moon to scale]
A scaled illustration of the spatial and size relationship between the sanctuary moon and the battle station. At this range it was inevitable that much of the moon would be struck directly by the station's remains.

Biocidal consequences

The most important consequence following the debris shower is what has been called "nuclear winter effect". This kind of cataclysm is believed to have befallen Earth on several occasions, each time due to the natural impact of an asteroid or comet. One such episode was the mass-extinction 65 million years ago (which eliminated a majority of extant species, including dinosaurs). Atmospheric dust blocks sunlight from reaching the surface, casting a pall of twilight and causing temperatures to plummet. Vegetation dies due to lack of light; and this causes starvation of herbivores. Carnivores persist for a while by feeding on carcasses, but they too must perish. Only tiny, hardy, primitive animals of rodent size or less may survive through the cold dark years. After several years, the fallout gradually settles, leaving behind a devastated biosphere in which a majority of the former species have perished.

The severity of the effect on Endor must be much greater than the versions projected for Earthly nuclear wars and single asteroid impacts, since the amount of dust involved is comparable to a small moon rather than insignificant portions of the planetary crust. Such is the magnitude of the Endor event that it is yet unclear whether the atmosphere would even remain breathable. The chemistry of the air, land and water may be grossly altered (because of the burning meteoritic material). The explosion probably is accompanied by a huge burst of deadly radiation. Additionally, the remains of the Death Star II might have been highly radioactive, depending on the characteristics of the station's power technology. The scope of mass-extinction will be nearly total. Only very simple lifeforms will survive on Endor, and the ewoks are not quite simple enough.


The mass-extinction event at Endor is an inevitable physical consequence of the circumstances at the end of Return of the Jedi. As such, it indirectly enjoys canonical status, even though it was not clearly portrayed in the film. A small number of official but unfilmed pieces of STAR WARS fiction have offered brief glimpses of post-Imperial Endor, and at first glance some of these references seem difficult to reconcile with the necessary reality of the cataclysm. There are two possible responses to this problem, and a spectrum of compromises between them:

  1. Reject the offending scenes in the novels and comics, or perhaps those works in their entirety. These pieces of fiction are official but non-canonical and therefore wherever there is a conflict they must yield to the facts and direct consequences of Return of the Jedi.
  2. Reinterpret the Endor scenes in the secondary works in an attempt to salvage them. Attribute new meaning to the circumstances so that they do not conflict with Return of the Jedi. Regard the aberrations as merely "a certain point of view" disguising parts of the objective reality.

Harmonisation of the continuity is preferable to rejection, since it leaves us with a broader and more detailed view of the STAR WARS universe. Of course, some compromises are unreasonable or impossible to make, and there will be many fans who personally prefer excision of the aberrant fiction for the sake of consistency or out of personal taste. The particular works which are affected by the Endor holocaust are examined below.

Return of the Jedi

For the first time, the Death star rocked. The collision [with Executor] was only the beginning, leading to various systems breakdowns, which led to reactor meltdowns, which led to personnel panic, abandonment of posts, further malfunctions, and general chaos.
Return of the Jedi novel, chapter 9, p.201 [illustrated edition].

One of the important implications of this passage is that the station's habitable surface layers locally include reactors which undergo dirty meltdown like nuclear reactors on Earth. They pose a danger to the crew. How much harmful radioactivity will the battle station's solid fragments and fireball deposit into the Endorian environment?

As soon as the battle station was destabilised, the rebel starfleet clustered together and moved between the moon's surface and the imminent explosion. This may have been a premeditated attempt to shelter the region surrounding the commando team, perhaps extending to an area as wide as a couple of miles. Although the rebel cruisers would be inadequate for affecting the majority of the moon-sized bulk of debris, judicious use of combined deflector shields, tractor beams and firepower might deflect dangerous fragments towards neighbouring regions of the moon's surface (rather than falling directly on the commandoes' heads).

The "fireworks" and dark circumstances of the rebel celebration are suggestive of the meteoric rain of debris and the spread of fallout across the sky. The Radio Play [p.182] explicitly states that pieces of the Death Star II were burning up in the atmosphere during the lighting of Lord Vader's pyre.

LUKE: What could be more fitting? It's a night of lights. Ewok victory fires. Rebel fireworks. Even the last pieces of the Death Star burning up in the atmosphere.

The rebel starfighters seen flying through the air are probably providing air cover protecting the commando team against straggler impacts. At the very least this would have been necessary during the first few minutes after the station's explosion. Pilots would blast apart any dangerously large fragments endangering the site. However, the smaller broken particles left by such intervention will still ultimately burn up and contribute to the atmospheric fallout layer. Furthermore, it is impossible for the rebels to break apart or repel more than an insignificant local portion of the total shower's mass, which is moon-like in magnitude. Other regions of the globe will still suffer their giant impacts, and the finer debris will still reach the high airborne soot layer. If the rebels ever had the ability to avert the biocidal calamity then they would also have had the ability to propel the whole battle station around the system before the destruction, which is a ludicrous proposition.

The rebels brought a large number of medium transports to Endor. their role is not immediately obvious, but the novel indicates that at least some of them were loaded with explosives and sent into deliberate collisions with Imperial ships. Surviving transports might have been useful for evacuating allied Ewoks, after being emptied of the deadly cargo. However there is not way in which the transports could carry and deposit useful heavy machinery like a portable planetary shield in the few minutes between the battle station's explosion and the time when the debris reached the moon's atmosphere.

The Truce at Bakura

Immediately following the Battle of Endor, the heroes of the Rebel Alliance departed to attend to a bizarre and urgent crisis in the Bakura system. They spent only one night at Endor, with Han Solo then morbidly inspecting the site of Anakin Skywalker's pyre. Nothing in this tale is affected by the Endor holocaust. Luke Skywalker and his companions can be excused for not knowing or understanding the extent of the calamity since:

X-Wing: Wedge's Gamble

Sometime between two and three years after the Battle of Endor, Wedge Antilles and members of his famous starfighter squadron were on a scouting mission on the galactic capital world, Coruscant. They toured the Galactic Museum as part of their task of monitoring the planet's social conditions (in preparation for New Republic invasion).

Antilles found several stuffed ewok specimens on display with a note that the innocent creatures had been made extinct on their native world through the actions of rebels. Though unwelcome news to members of the squadron which detonated the battle station, this report appears to be objectively true. The museum display provides satisfying corroboration for the realistic fate of the ewoks, but of course it is not relied upon as primary evidence. (The primary facts are those events of Return of the Jedi which point to the disaster.)

Some readers have assumed that the ewok extinction reported by the prestigious Galactic Museum is nothing more than a lie serving Imperial propaganda. However it is important to realise that the most effective forms of propaganda do not falsify verifiable truths and circumstances; instead they weave a preconceived pattern of significance through cleverly judicious use of available objective facts. It is true that a few mistruths were told in Museum displays dealing with Emperor Palpatine's motivations at Endor, but those situations were no longer open to testing and disproof. Demonstrably false factual claims about ewok extinction would not serve the propaganda machine very well.

From the Imperial point of view, the holocaust at Endor was an act of reckless ecological vandalism by wild political fanatics. For the Rebel Alliance, the devastation was an unfortunate side-effect of the necessary destruction of a war-machine which was poised to deliver worse destruction throughout the civilised galaxy.

The pilots of Rogue Squadron, particularly those who were involved with the Battle of Endor, would probably not know about the subsequent fate of Endor's natives. The rebel leadership must be sufficiently ashamed of the biocide to hold a general cover-up, and they're probably tactful enough to deliberately avoid bringing the debacle to the Rogues' attention.

X-Wing: The Bacta War, Wraith Squaron & Iron Fist

In these novels Endor is mentioned, but its condition is not. Ewoks are mentioned, but their circumstances are not. The closest these books come to showing a native of Endor is the use of a hypothetical Ewok recruit, who is an emigrant anyhow. There are hints that some mid-level and junior New Republic pilot officers are unaware of the fate of Endor and any ewoks who remained there. Evidently, the New Republic's official coverup persists, but otherwise these novels tell us nothing about the environmental catastrophe.

X-Wing: Solo Command

In this novel a number of Ewoks escaped from Warlod Zsinj's Binring Biotics Facility, with the aid of a New Republic sympathiser. This demosntrates that unknown numbers of Ewoks survived for some time in Imperial captivity far away from their homeworld, some may have been kept as luxury exotic pets, and some eventually entered civilian life in the greater galaxy. This suggests that the species itself may not be in depserate danger, regardless of the thoroughness of whatever evacuation may have taken place immediately after the destruction of the second Death Star.

Dark Force Rising

Princess Leia Organa-Solo chose Endor as the location for her rendezvous with noghri super-commando Khabarakh, approximately five years after the disaster. The orbit chosen for the Millennium Falcon passed through the position of a "stain" in the Force marking the event of the Emperor's betrayal and death. [This encounter tells us something about the kinematics of the dark Force nexus, since there is no such thing as a universal frame of reference; the nexus must be either in some kind of "orbit" alongside the moon, or else it is linked to the moon itself. But this should be the subject of another commentary.] The full disk of the moon was visible in the sky. No landing was made.

As seen by the Princess, the moon seemed "lush" and "green". At first glance, this appears to be incompatible with the wasteland which Return of the Jedi leads us to expect. However the lushness may be a misleading impression given by the green colour. There are more ways for a world to be green than simply through the presence of foliage. The greenery of Endor at this point in its post-apocalyptic history must be due to either copper salts or algae suspended in the air or scattered on the desolate ground. (Atmospheric dust should have mostly settled and thinned within the first few years after the disaster, so the surface might now be visible from space.) Simple forms of microscopic algae or photosynthetic bacteria might be the forms of life best equipped for surviving several years of lightless dormancy. In a best-case scenario, the greenery might be lichens or simple hardy grasses.

[Endor orbit, 5 years after the cataclysm.]

Dark Empire

Two ewoks were sighted among the rebel forces grounded at the wreck of the star destroyer Liberator near the damaged Imperial Palace on Coruscant. The Endor holocaust has no implications for this scene, since the moon never appeared in the comic and the ewoks could simply belong to whatever small handful of survivors the rebels were able to evacuate in the days following the Battle of Endor. Otherwise these offworld ewoks are representative of the scarce individuals who left their moon with traders before the commencement of the Empire's military activity there. This group could easily be the entire ewok population of the universe.

[Ewoks in battle on Coruscant.]

Dark Apprentice

Seven years after the Battle of Endor, a young Sith initiate named Kyp Durron paid a visit to the site of Lord Vader's funeral pyre. He did not seem to notice anything amiss. An ecological disaster at Endor is grounded in the canonical facts of Return of the Jedi. Now what does this tell us about the continuity status of Durron's excursion? The passage we're interested in is pp.293-298 of Dark Apprentice. It mentions the existence of "trees", a "forest", "twigs and dead leaves", "underbrush", one live Gorax, a handful of live Ewoks perceived to be huddled in their homes, and a few noises. Note:

* *
The Gorax is a miserable carnivorous giant residing in a peculiar castle on Endor. Its gross similarity to the stranded humanoid marauders of King Terak suggests that it could be an abomination deliberately created by the Dathomirian witch Charal, as part of her malevolent experiments with the Dark Side of the Force. (Ancient Sith Lord Exar Kun performed similar procedures on willing Massassi warriors. Emperor Palpatine's adepts on Byss used human stock to create giant symbiotic soldiers known as Imperial Sentinels.)

Aside from neglecting the climatic disaster, the credibility of a literalist interpretation of the Dark Apprentice is undermined by the existence of a few comparable continuity problems in material written or edited by the same author. For instance:

Comparable Disasters


At some point in his career, Lord Vader's forces were engaged in a large space battle over the planet Honoghr, homeworld to the fierce noghri species. A capital ship belonging to one of Vader's enemies crashed to the surface, effecting a climatic disaster. Though the immediate climatic effects of such an event would be much slighter than the more massive calamity at Endor, (since the size and severity of the impact is less), the damage is much more lasting. The principal cause of the continuing devastation on Honoghr is contamination by noxious chemicals used in the crashed vessel. Only a small area of clean land remains habitable. Lord Vader brought aid to the noghri, who pledged allegiance to him, but agents of the Emperor modified many of the land rehabilitation droids to sow a genetically-engineered kholm-grass which actually enhanced and perpetuated the poison. So, even two decades after its cataclysm, Honoghr is not even graced by the greenish slimes and lichens which appear to have recovered a hold on Endor.

* *


During the Palpatine Era, the planet known as Maltha Obex was a desolate waste in the grip of a fierce ice-age. New Republic scientists and an intelligence team led by Lando Calrissian discovered that it had once been a more balmy world inhabited by an intelligent species known as the Qella. Several thousand year ago, unnoticed by the Old Republic, the Qella faced a disaster which promised their extinction.

One of their world's two moons was a small captured asteroidal body. Perturbed by a larger natural moon, its orbit was decaying towards an inevitable impact against the planet. With only a century to prepare, the Qella were unable to develop sufficient starfaring technology to evacuate their entire population, nor sufficiently powerful repulsors to deflect the moon. Their bioengineers did manage to develop another slight hope for the species' salvation, but the planet itself met its due devastation. The moon impacted, and the resulting nuclear winter effect kicked the planetary climate into a deep ice-age state.


The details of extraterrestrially-induced mass-extinctions on Earth are still contended by geologists. However it seems as if most scientists believe that an asteroid or comet about 10km in diameter impacted sixty-five millions years ago. An impact crater at least several hundred kilometres wide and dating to the correct age lies beneath the surface of the northwest part of Mexico's Yucatan Peninsula. Distinctive chemical elements which are rare in the Earth's crust but relatively common in asteroids (and comets) is found enriched in a 65Myr-old clay layer worldwide. Most individual organisms died and at least forty percent of all animal species (including most large animals) vanish from the fossil record at this point.

It is believed that the impact caused the mass-extinction via the kind of nuclear winter effect described in previous sections (climatic alteration due to dust and soot in upper atmosphere). The necessary differences between the Earthly and Endorian situations are that much more matter was injected into the Endorian atmosphere, the matter may have been radioactive, and the moon probably did not suffer global tidal waves (because instead of oceans it has only a smattering of small local disconnected lakes). The composition of Earth's atmosphere probably would not have been as severely altered.


It has been speculated that the moon Yavin IV might have been adversely affected by the explosion of the original Death Star. Whether or not the first Death Star was close enough for Yavin IV's surface to be affected, the rebel base surely had a sufficiently good deflector shield to locally repel any falling debris onto neighbouring areas of the moon's surface (so the base need not fear obliteration by a direct impact). The rebels probably left the moon within days of the battle anyhow, since they would rightly fear Imperial reprisals.

The Death Star was not close to the moon when it exploded. It had just rounded the limb of the planet Yavin, ready to fire the superlaser. According to indications on rebel tactical displays and the known diameter of Yavin, the battle station was about 250,000km away from YavinIV. The Death Star II was only about 2000km away from the Endor moon.

Because of the great distance between the Death Star and the moon, only a tiny fraction of the exploding mass would intercept Yavin IV. Much (perhaps most) of the debris would have fallen into the gas giant, which dominated the battle station's sky. The portion striking the moon would be no more than a quarter of a percent of the station's total mass - equivalent to a cube of the station with a side length of 8km.

A single solid impact of this size would cause a big mass-extinction event, but the Death Star is partly hollow. Realistically we would expect a large number of small- to medium-sized impacts distributed over the globe. Individually, the imapcts would be nasty to anyone within a few dozen km. There may be some climatic problems, but nothing on the scale of the Endor disaster, where much of the moon's surface would be literally smothered with wreckage.

Attacked Worlds

Biocide is well within the standard technological capabilities of the galactic civilisation. Interstellar warfare results in the deliberate or accidental erasure of life from planets from time to time. The operation of cleansing a hostile world by bombarding it to the point where the crust is melted is code-named "Base Delta Zero" in the lexicon of the Imperial Navy, but it is not an exclusively Imperial procedure. Victims of such operations have included Caamas and Emberlene [Spectre of the Past], and the Rebel Alliance administrative outpost at Dankayo [Scavenger Hunt]. In the former example, the planetary surface remained aflame for years after the attack. The planet Meridias [Planet of Twilight] was left a charred radioactive wasteland centuries before the rise of Palpatine.

According to X-Wing: Wraith Sqaudron, the planet Toprawa was sterilised after the Battle of Yavin. This was Imperial punishment for the theft of the Death Star plans from a facility on that world. The locals were innocent, but they were reduced to a pre-industrial existence, and forced to partake in rituals of public grovelling in order to receive supplies.

In Vector Prime a deliberate moonstrike was inflicted on a populated Outer Rim world by the Yuuzhan Vong. It was a small moon, really only as great as a modest or large asteroid. However its impact obliterated civilisaztion and presumably sterilised the globe.

Fate of the Ewoks

No animal larger than a few kilograms and incapable of long sheltered hibernation could survive the Endorian calamity. The air might even have been poisoned and deoxygenated for a few years until simple plant life could return to growth. If so then it is possible that all animal life perished. In any case any ewok on the surface who was not equipped with impressive high-technology survival gear and a nuclear shelter must have died.

For those unfortunate beings not painlessly obliterated by the impact concussions, the initial night of celebration would linger on and on with days of darkness. A chill would fall, the waters would turn to ice and the vegetation would wilt into death or dormancy, depending on species. Provided that radioactivity was insignificant and the air remained modestly breathable (a very generous assumption) the doomed ewoks might survive for days or weeks huddling around bonfires, until they starved.

The species was not perfectly confined to its native moon, and some off-world individuals seem to have survived. Exact statistics for ewok emigration are unknown but probably small. Although the Galactic Empire had declared the moon a natural sanctuary, at least several smugglers had taken ewoks offworld as stowaways, hitchhikers and perhaps slaves. These encounters are known to have happened long before the start of the Death Star II construction project. It seems likely that the forces of the Rebel Alliance evacuated some ewoks in the aftermath of the Battle of Endor, though they did not have sufficient transport capability or enough time to gather more than a small fraction of the scattered global population. Members of the tribe which had adopted the Rebel Alliance were probably given preferential treatment. The presence of two living ewoks among the forces of the New Republic Navy was confirmed in Dark Empire, six years after the disaster.

During the Thrawn campaign, the neutral planet Svivren boasted an ewok population. The Svivreni detest the Galactic Civil War, and they successfully resisted both the Imperial remnants and the New Republic after Palpatine's fall. Thus Svivren is an ideal sanctuary for Endorian evacuees. Statistics in The Last Command Sourcebook hint that the ewoks comprise the largest minority group on the planet.

If there truly were ewoks on the moon during the later visit of Kyp Durron then they must be a recently-resettled group, with modern survival equipment if the climate remains hostile. They may be part of a deliberate rehabilitation and terraforming project executed by a benign agency with galactic-standard technology.

Though resettlement of offworld ewoks ends the species' technical state of extinction on their homeworld, the fate of the ewoks is not yet secure. It is not clear whether the remnant ewok population is large enough for the species to remain viable without extensive genetic therapy to counteract the ills of inbreeding. If the Death Star II fallout was radioactive then the ewok returnees would also need to contend with radiation sickness, enhanced rates of cancer and mutational birth abnormalities.

Political Implications

The ewoks were marginally known to the outside galaxy before the cataclysm at Endor. Some ewok languages must have been cursorily studied by galactic anthropologists, since they were incorporated into the linguistic repertoire of at least one protocol droid which was over a hundred years old4.

The ewoks were known to the Imperial scouts who contributed to the selection of the moon as the Death Star II construction site [The Illustrated STAR WARS Universe]. They must have been known to the security troops on the ground. They probably were known to at least some civilian departments of the Imperial government, since the moon was designated as a nature sanctuary. Endor was probably reserved for the purpose of protecting the natives from exploitation, and allowing them to progress at their own technological pace. Whether the "sanctuary moon" status was granted by the Empire or Old Republic is unknown.

The Imperials were not consistently pure in their motives towards the ewoks. Emperor Palpatine did not seem interested in his government's standards of environmental protection and non-intervention with primitive species. In fact he left contingency orders for the moon's destruction in the event that the rebel commando team succeeded in lowering the security shield. This may have been no more than a taunt for Luke Skywalker, since the moon's nearby explosion would seem to threaten the station itself, unless the Death Star's modest internally-generated shielding ensured safety,

As the battle station rocked from the impact of Executor and internal damage inflicted by rebel starfighters, Moff Jerjerrod was already attempting to carry out the command. The station was already turning upon the moon when Palpatine began attacking Skywalker, as demonstrated by the motion of stars visible through the throne room windows. By the time of its destruction, Death Star II had turned away from the rebel fleet and the superlaser almost reached firing orientation.

The record of the Rebel Alliance's involvement with the ewoks is also far from flattering. The commando team clearly exploited the naive natives in their attack upon the Imperial ground facilities. Though the rebel starpilots deserve credit for thwarting Jerjerrod's attempt to eliminate all Endorian life, the rebel actions indirectly caused gross environmental damage. To establish the degree of culpability we must consider whether the rebel leaders and tacticians were aware that Endor was inhabited.

At the Rebel Alliance general briefing there was no mention of native intelligent life. However the presence of Ewokese in the linguistic repertoire of C-3PO suggests that although obscure, the ewoks should have been known to mission planners. Perhaps the ewoks were omitted from the information leaked to the Bothans by Palpatine; it would be quite in character for the Emperor to entice the Alliance into ugly moral ambiguities, forcing them into an accidental genocide. Alternatively, the ewok information may have been received by rebel leaders but deliberately omitted from subsequent briefing reports so that the lower officers and enlisted men could fulfil their orders without guilty qualms of environmentalism.

In the Return of the Jedi Radio Drama, Princess Leia explicitly complained that her reports made no mention of intelligent lifeforms. At least the rebel commandoes were ignorant of the ewoks' existence, and were dealing with the primitives in good faith. That's not to say that there couldn't have been concealment higher up the rebels' executive chain.

Their strategic calculus might demand that the battle station be destroyed, for the greater good of the majority of sapient species in the galaxy. Considering the importance of the Emperor and his superweapon, a biosphere lacking sapient natives would be a justifiable sacrifice, which could save other worlds from obliteration. War is cruel and desperate, and the rebels might not have reconsidered their attack under any circumstances. However some may believe that a knowing willingness to endanger an intelligent species would expose severe hypocrisy in the propaganda of the Alliance / New Republic. Whether or not the rebels had foreknowledge, the fate of Endor would probably remain a secret of the New Republic government. Although the uninformed personnel of the fleet and ground operations are blameless, the decisions of the highest rebel leaders deserve scrutiny. It may have been clumisiness and poor research, or it may have been ruthless utilitarianism.

The truth, which remains unexplained to this day, is likely to involve more clumsiness than malice. Rebel intelligence was not excellent in the Battle of Endor. Their spies clearly were manipulated by the Emperor to the extent of providing wholly false information about the condition of the Death Star II and the distribution of security forces.

In any case, the disaster situation must have been an embarrassment after the battle. The inclination of Endor references in post-Return of the Jedi stories hints at a high-level cover-up. Most citizens and military personnel of the New Republic would be kept unaware of the deep shame which accompanied the birth of the new regime.

It is unknown whether the rebel forces and the successive New Republic government made any systematic efforts to evacuate and eventually resettle ewoks in secret. It seems likely that they would have at least indulged in the rescue and protection of a token number of the ewoks from the tribes who had allied themselves against the Empire. The neutral Svivreni hosted a large population of ewok immigrants on their homeworld; they probably were evacuees [The Last Command Sourcebook]. A long-term terraforming project is possible.


The ewok population is effectively extinguished. Most were killed in a mass-extinction event affecting life on their homeworld, due to unavoidable fallout and debris from the destruction of the Death Star II. The Rebel Alliance is culpable but perhaps innocent. All ewoks would have been better off if the tribe which made contact with the rebels continued with their original plan of killing and eating the commando team's leaders. However once the shield fell and Jerjerrod began his attack, the ewok's best interests were served by the Alliance naval forces bringing about a swift destruction of the battle station; the chance of ecological devastation ameliorated by partial evacuation and rehabilitation is better than near-instantaneous obliteration of the whole moon.

Knowledge of the Endor Holocaust is based primarily on the facts of the Return of the Jedi film, and the supportive passage in the Wedge's Gamble is only secondary corroborative evidence. None of the Endor references in other tales of the New Republic era are in unresolvable contradiction with the catastrophe, though a very precise interpretation of Dark Apprentice may be necessary.

Studying the mechanics of the orbit and explosion of the Death Star II reveals, in brief:

Avoiding the Endor Holocaust is completely impossible. It is an inevitable consequence of observable facts of the Return of the Jedi film. Endor is a depopulated wasteland.


  1. This makes some people understandably uncomfortable. I only discovered the Endor Holocaust by accident. I studied the Death Star II orbit in order to gain a measurement of the station's size which is independent of the (incorrect) value given by West End Games. I always imagined that the site of Vader's pyre would become a place of gentle things; a Light Force Nexus analogous to the Dark Nexus on Dagobah. But I've done calculations and I now accept the inevitability of the bleaker reality.
  2. To be precise, the Death Star II's orbital period must match the sidereal period of the moon: its period of rotation with respect to the non-inertial background of the universe, not in relation to Endor's sun or any other local body.
  3. The composition of the station must have involved substances of immense strength. This may have included metals, reinforced through by the action of inertial dampers or "structural integrity" fields. It may consist of exotic carbon compounds or superlattices designed for strength greater than substances known on Earth. For the convenience I'll refer to it all as "metal", understanding that the true chemical nature might be profoundly different.
  4. According to SWCCG cards and earlier sources, C-3PO was well over a century old in the classic trilogy. C-3PO was reconstructed by Anakin Skywalker in TPM, which was 36 years prior to ROTJ. Some components predated the rebuild. The processor that allows the droid to interpret millions of languages is likely to be one of the older components, since a Tatooine slave boy is unlikely to be able to program so much information without significant outside resources.


Why don't we see debris raining from the sky during the ewok celebration?

We actually do. We see rebel starfighters flying amidst an abundance of material breaking up in the atmosphere. The Return of the Jedi radio play describes it as material from the Death Star. Furthermore the whole sky is darkened, as if overcast with fallout. Large ground-shaking impacts matching and exceeding the yield of nuclear weapons must have struck parts of the moon beyond the immediate vicinity of the village.

Why couldn't the rebel fleet use tractor beams to move the debris somewhere safe?

It's a matter of inertia and energy. The trouble with any attempt by the rebels to do something about the explosion is that the combined mass of the rebel fleet is equal to only a tiny speck of the Death Star's surface. If they used tractor beams on the station's wreckage the result would be for the ships to be dragged by the debris while the debris would be only slightly deflected. The difficulty and amount of energy involved in containing or shifting the stuff of a moon-sized explosion is the same or greater than for moving the intact battle station around. If the rebels had been physically able to do something about the Death Star II explosion, they also would have had the capability to knock the station around the Endor system like a billiard ball. They plainly weren't able to do that. Besides, the debris cloud was close enough to reach the forest moon within minutes or seconds, so the rebels had little time for large celestial manipulations.

Why couldn't captured Imperial ships help to do the same?

Because the combined power and mass of the Imperial and rebel ships at Endor is insignificant compared to the energy/timeframe of the explosion and the mass of debris.

Could the disaster have been averted if the Death Star was actually moving towards the Alliance fleet [and away from the moon at its moment of destruction]?

In principle you could inadvertently protect the moon, if the station's initial outwards motion was greater than the maximum velocity of the fireball (of the eventual explosion). But in that case the fireball would have seemed to be receding away in the sky, rather than having pieces falling down as seen in the movie. For viewers on the ground, it would have seemed to be shrinking. As shown in the movie, the fireball expanded much faster than the velocities typical of orbital motion at the Death Star's altitude. In any case, the operational status of the station's sublight propulsion systems is uncertain.

Does it matter whether the bulk of the station was vaporised?

No. Material that is turned to vapour does not vanish. Vapour cools rapidly by radiating its heat to space and also by conducting heat to air once it hits the atmosphere. The result of this cooling is that the vapour would recondense as solid soot, like water precipitating as snowflakes. Indeed the margins of the Death Star II explosion appeared sooty before many of the ground troops noticed the fireball. Therefore some condensation began to occur only seconds after the detonation. In any case the explosion shows numerous large tumbling solid fragments, each of which alone is sufficient to cause a global mass-extinction event. In summary, there are two extreme alternatives, and a mixture of intermediate possiblities in between: (1) big solid chunks of the DS impacting on the surface and throwing up fallout dust; or (2) huge volumes of metallic vapour condensing in the atmosphere to give a similar amount of dust.

What if it wasn't metal?

Substances that don't react chemically in the Endorian atmosphere will end up as condensed atmospheric soot, either directly or via impact ejecta. This is the standard scenario described above.

If the station were composed of combustible materials involving lighter elements like C and H, the byproducts would be water and carbon-dioxide. However the mass of solid material visible at the station's surface is large enough that it would deplete atmospheric oxygen if it burnt upon entry. (At the maximum possible size of the moon (5600km radius) the mass of atmosphere should be about 4x1018kg. If the station's mean density is at least equal to air — for a total mass of about 3x1017kg — then the combustion of all this material would consume much or all of Endor's free oxygen.)

What if much of the material of the station was annihilated in matter/antimatter or similar reactions?

Then a horrendously lethal burst of gamma rays would have burnt everything on the moon with a line of sight to the explosion. That didn't happen in the movie, and we saw huge chunks of debris moving towards the moon. An impact by any one of them is sufficient to create a climatic catastrophe on par with the Cretaceous-Tertiary extinction on Earth.

What if the debris goes into hyperspace?

Sending the debris into hyperspace (presumably involving local misfiring of hyperdrive systems within the station) would solve nothing. It is a well established fact that objects in hyperspace collide with objects in realspace destructively. ("You can fly right through a star ... and that will end your trip real quick.") The debris that flies off in the direction of the moon will crash into the moon. The only question is whether the material would revert to realspace or just dump its mass-energy in the moon's atmosphere. The former scenario will have consequences similar to those outlined in the main parts of the commentary. The latter scenario effectively means irradiating the near side of the moon with the equivalent of the annihilation energy of much of the station's mass — an unfathomable dosage of hard radiation.

Could the rebels have activated the shields from Endor right after the explosion of the Death Star II, thereby containing most of the matter within the confines of the shield radius?

No. The trouble is that they blew up the shield already, in order to allow the rebel fighters access to the station.

The Endor moon has lower gravity than Earth. Won't this prevent a calamity?

True, the gravity must be lower than Earth's. That circumstance is estimated and taken into account in this commentary. The gravity cannot be indefinitely low, otherwise there would be no atmosphere, and the humans and ewoks on Endor would bounce high whenever they attempted to walk. The Endorian gravity msust be at least as great as on Earth's airless moon, and even there objects falling from space land at violent, crater-inducing velocity.

Furthermore, the observed expansion speed of the debris chunks is much greater than the speed that the same material would attain by falling freely from the sky. The chunks impact harder than free-fall velocity.

The moon and ewoks seem unharmed in the Ewok movies. How can this be?

Those movies document events that took place before ROTJ and before the construction of the Imperial outpost in the system. This is acknowledged in official timelines and literature concerning the Ewok movies.


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