Epsilon Indi 2 D or “Tigua” (tee-gah) as it is nicknamed, is the most hospitable of the three life-bearing satellites of the large gas giant known as Lee, and represents one of the settlement milestones since humanity commenced interstellar expansion in 2105.
Unlike the other planetary systems upon which a reasonable level of remote surveying had been performed, the gas-giant-laden Epsilon Indi system presented early researchers and interstellar mission planners with considerable difficulties. With three borderline large gas giants clustered in the inner, life and close outer zones of the system, standard exoplanet detection methods were frustrated, unable to make sense of the small, yet conflicting readings that resulted from the relatively low masses of the objects, and their overlapping gravitational effects. For much the same reason, clear data on their satellites was problematic and visual enhancement studies only confirmed that several bodies of the second gas giant were wreathed by some form of atmosphere. Specific atmospheric composition, hydrographics, and basic habitability data remained a mystery until the first surveying and pathbuilder mission arrived in 2107.
As it turned out, Epsilon Indi 2 D was the natural site for the first green world colony beyond that established on the often tempestuous surface of Terra Nova (Alpha Centauri III). With an aggregate planetary temperature only 5 C degrees beneath that of Earth, the tropics and subtropics are very comfortable. Lacking any appreciable axial tilt, there are no seasonal variations. This impact upon the local biomes includes polar icecaps which show little change, and a water cycle that favors equatorial rains and middle latitude snowstorms.
Of greater importance to the colony’s founders was the discovery that Epsilon Indi 2 D was not only rotating independently of its parent planet (i.e., was not “tidally locked”) but also possesses a molten core, thereby producing magnetic fields which vastly reduce the amount of radiation that ultimately reaches its surface. However, as was to be expected, the influence of its parent gas giant Lee retards its rotational rate, producing unusually long days and nights, with all the weather perturbations one might expect therefrom.
Without tectonic plates, Epsilon Indi 2 D’s variation in elevation is modest by true planetary standards, resulting in shallow (and predominantly equatorial) seas with extensive archipelagos, few large rivers (but more widely dispersed, often marshy, watersheds), and few true mountains.
After the pathbuilder mission returned its findings, settlement proceeded apace, with the first spaceport being established on an average-sized island in a small archipelago just south of the equator. Although early corporate investors pushed for immediate settling upon, and exploitation of, the larger contiguous land masses, the Commonwealth commission charged with developmental oversight and safety deemed an island a better site. Having little knowledge of the wildlife, they reasoned that if there were any undetected dangers from the flora or fauna, it would be far simpler to “sanitize” a small, water-bound landmass. This spaceport ultimately became the satellite’s major city: St. John’s or, more commonly, SinJin’s.
With .8 gee and a steady, mostly gentle climate, Epsilon Indi 2 D is quite comfortable for humans. The only routine perturbations in its meteorology are the equalization effects that occur during its long day/night cycle. Winds gust strongly during the long dusks and dawns, since the most marked air-temperature equalizations tend to occupy a longitudinal band that moves with the day/night terminator line. The worst weather occurs when polar-equator pressure fronts intersect with this moving line, spawning small hurricanes and tornadoes. Weather effects on Epsilon Indi 2 C, even when forbidding, lack the intensity of planetary weather simply because of its far more steady climate: profound pressure and temperature extremes are rare.
The only noteworthy exception is the temperature intensifications that result from the long days: late afternoon highs and post-midnight lows can get quite severe, since this is the peak point in the thermal gain/loss cycle that results from slow planetary rotation.
Since air and oxygen pressure are somewhat lower that human norms, humidity tends to be low, even in the littoral regions, where the mediating effects of the water produce the best climate on the satellite. Although extended physical exertion makes the use of a compressor mask advisable, the slightly low pressure is not otherwise bothersome.
The primary challenge to human habitation is more an annoyance than a threat: an airborne unicellular organism that attempts to infest unprotected human respiratory tracts in its quest to find a warm, moist host organism.
Carried on the wind, this simple creature resembles terrestrial bacteria in its lifecycle and survival strategies (although it is quite distinct in terms of its xenogenetics and chemical make-up). Although it cannot utilize human tissue for feeding purposes (too many biological differences), it finds human hosts to be excellent safe havens: being wind-borne, the organism is constantly in danger of being carried back around to the night-side of the planet, where, in the long, higher-altitude cold, it may perish or become inert. Consequently, its life cycle involves finding a warm, moist host from which it cannot easily be dislodged, there sustaining itself on moisture, heat, and a few simple compounds.
Although it cannot grow swiftly in the human respiratory tract (since it lacks sufficient nutrients), it also cannot be easily driven from it, since humans lack the natural defenses of the indigenous, air-filtering fauna of Epsilon Indi 2 D. They possess mucus-based respiratory linings that slough off on a weekly basis, thereby carrying any nascent infestation of this organism into the digestive tract, where it is denatured quickly and completely. In humans, however, successive layers of the organism begin to accrete, constricting breathing and leading to dehydration, the symptoms mimicking high-altitude asthma attacks in many regards. Mortality for humans is approximately 5 percent, with double those rates (or more) for respiratory “at-risk” populations (children, elderly, health/immune-impaired).
Although healthy persons will ultimately throw off the infestation (since the lack of nutrients starves the first generation of cells, and the later, accreting levels are often deprived of moisture by the layers beneath and above them), common sequelae include a permanently compromised respiratory system, putting individuals at greater risk when they contract terrestrial respiratory infections and/or subsequent infestations of this indigenous organism.
Fortunately, a combination of mitigation technologies and pharmaceuticals have been developed, reducing the dangers of infestation to beneath those associated with common bronchitis. The first mitigational therapy is a prophylactic inhaler that suffuses the respiratory tissues with several harmless chemicals which the indigenous organism finds mildly toxic, thereby preventing it from establishing a toe-hold in the mucosa. Although quite effective, this was deemed an insufficient methodology on its own, and colonists were still compelled to wear filter masks to ensure their long term safety. It was also deemed necessary to have another means of resisting the infestations, in the event the supply of inhalers dropped or was interdicted.
The second solution was ultimately far more effective and completely non-invasive, although it remains a strictly regional answer to the challenge. It was discovered in 2110 that the organism sought out its hosts through a very keen sensitivity to infrared emissions, but only along a very narrow set of wavelengths. It was also determined that they avoided slightly more energetic emissions as being “too hot”: their version of pulling back a hand from a hot stove top.
The answer: emitter towers that project pulses of higher wavelength infrared. The exposure is decisively subclinical for humans, but works as a repellent for the unicellular organisms, which demonstrate a capacity for limited airborne motility. In order to maximize the area covered by these emissions, and to minimize their effect upon the colonists and their equipment, the emitters are mounted in towers that were originally planned to serve other purposes: short range power beaming, wireless communication, ground control and guidance for transatmospheric shuttles and landers, and even tether/refuel sites for VTOL and tilt-rotor vehicles. Consequently, the settled regions of Epsilon Indi 2 D, but particularly the environs of SinJin, are marked by the tall, multipurpose towers scattered throughout the community, and at its peripheries.
Despite a burgeoning population in excess of 100,000, the worlds of Epsilon Indi are still most notable for the marginal exploration and almost cursory mapping that has been carried out upon them. In large part, this is because of the plenitude of satellites in the system, and the strong advantages in human suitability offered by Epsilon Indi 2 D, Tigua. The other worlds which support life—the even more alien biosphere of Kitts, and the marginal “brown world” satellite of Loupe—have only been sparsely settled. No other satellites boast permanent habitation, despite the fact that there are 19 others with diameters of at least 1000 kilometers. Mining and other resource exploitation initiatives are in early stages, simply because so much of what was required for initial use and commerce was found right on the surface of Tigua.
Visitors to Epsilon Indi may find themselves perplexed by the seemingly unrelated, and even peculiar, names of its many planets and moons, but there is in fact a common origin—one that persons familiar with the Caribbean detect immediately. One of the cartographic experts with the original pathbuilder mission in 2107 remarked that, like the West Indies on Earth, Epsilon Indi had plenty of possible ports of call. The two parallels—”Indies” and Indi, and the many islands or moons—stuck, and proved itself all the more appropriate with the passage of time. Unlike most systems, where the duration and distance of most interworld journeys involve many days and tens or hundreds of millions of kilometers, movement between the worlds of the Indis is often quite rapid. Almost no journey between the worlds of a single gas giant will ever involve a distance of more than 15 million kilometers, and it is usually much, much less, since transits are timed to coincide with the closest possible orbital approaches, and can often make use of “gravity assist” slingshot trajectories.
Recently, because of this, and because so many of the moons of the system boast at least some volatiles (usually in the form of frozen water or carbon dioxide), the media has seen fit to characterize a few isolated cases of brigandry and barratry as the first indicators of a trend toward yet a third historical similarity between the “Indies” and the “Indis”: piracy. While it is true that the satellite systems of the three sequential gas giants are ideal for the operation—and concealment—of small craft, there seems to be little opportunity for ship-to-ship intercept and seizure. As most military authorities point out, effecting rendezvous between spacecraft—particularly in order to conduct boarding actions and cargo capture—is almost impossible to compel by force. As one European Union official put it, “it is difficult enough to dock with another craft that is trying—very hard—to join itself to yours; to effect rendezvous with an actively uncooperative, or even hostile, hull is so unfeasible as to be ludicrous.” Nonetheless, traveller’s warnings are in effect system-wide regarding the charter of small craft for private excursions. Individuals without compelling commercial or research needs must expect that they will be denied permits for such excursions.
With the majority of the moons of the three gas giants named after the islands of the Caribbean, the gas giants themselves are named for the grouping of those islands. The innermost—Antilles—is named for the Greater Antilles; Lee, the second gas giant and home to the habitable worlds in the system, is short for Leeward Islands; and the outmost, Wind, borrows its name from the Windward Islands. The asteroid belt one orbit further out from Wind was to be named Roque, after the de la Roque shoals, but the itinerant prospectors of that region reduced the name to Roka, then Rock, and ultimately Rock-Show, instead of Roque Shoals. They like to claim that their name is not only far less pompous, but far more descriptive.
Travellers to Epsilon Indi are advised to send accommodation requests at least three months in advance of their travel. It is unlikely that a reply will be received before you depart, but the ratio of room inventory to demand ensures that this advance warning will secure dirtside housing. Food prices tend to be high, as is the case on all worlds that are not cleared for local comestibles agriculture. Travellers should be aware that national or even bloc currency will frequently be rejected by both small and large businesses in the system: the economic currency unit (or “ecu”, “unit”, or “credit”) is the medium of exchange for all transactions.
The high volume of persons bound for Epsilon Indi should not discourage individuals who wish to travel to the system for a visit. Most persons who choose Epsilon Indi as a port of call are not stopping there, but usually taking a break before heading further down to the other habitable worlds of the Big Green Main, particularly the two high-compatibility planets, Delta Pavonis III, and Zeta Tucanae II. As the “Doorway to the Big Green Main,” Epsilon Indi is a collection and departure spot for various long-contract colonial personnel, Earthbound cargos, and outbound equipment and supplies for the further colonies. Consequently, although it is second only to Junction (Lacaille 8760) as a multi-destination hub, it has far fewer permanent inhabitants than one might suspect, and facilities are not overtaxed, but expanding to keep abreast of increases in demand.