Armored Tears
Page 28
The Luhman-16 system is a brown dwarf system, approximately 6.65 light years from Sol, in the constellation Vela. Prior to 2028, brown dwarf stars of its type were assumed to be impossible as candidates for habitable exo-planets and the Luhman-16 system was not regarded with much interest.
The Luhman-16 system consists of two "brown dwarf" stars orbiting each other slowly at a distance of approximately five hundred million kilometers. Both are of the sort designated as "failed" stars, meaning that their heat comes from gravitational compression rather than from actual nuclear fusion. The larger of the two, Luhman-16A, is about 5 times colder and 20 times smaller than Earth's sun, while the smaller, Luhman-16B, is approximately half the size of, and even cooler than, its larger twin.
There is one super-Jovian exo-planet orbiting Luhman-16B, and a second, terrestrial exo-planet (Arcadia) closely orbiting Luhman-16A.
Luhman-16A has been named "Ravi" after one of the names of Surya, the chief solar deity in Hinduism. Luhman-16B has been named "Ragyi," after one of the wives of Surya. The super-Jovian planet orbiting Luhman-16B has been named "Prabha," after another one of Surya's mythological wives. The terrestrial planet orbiting Luhman-16A was originally given the name "Saranyu," after yet another one of Surya's wives, but was renamed "Arcadia" when it was discovered to be habitable.
Arcadia was first discovered by long distance observation, by the staff of Dr. Taran Bhatnagar of the Indian Institute of Astrophysics in Bangalore in 2028. The complex gravitational interactions of the Luhman-16 system had the effect of hiding the presence of a terrestrial-mass planet closely orbiting Luhman-16A from earlier Earth based observers, but Dr. Bhatnagar staff had the advantage of more sensitive instruments than had been previously available.
Once Arcadia was discovered, it quickly became a candidate for further exploration by means of the then newly developed Morris–Thorne wormhole technology, colloquially called "Tannhauser gate" technology.
The first Tannhauser gate to explore the newly discovered world was initiated in 2032 and the first gate transit to the orbit of Arcadia occurred in 2039. Initial surveys found an oxygen-nitrogen atmosphere and liquid water and the planet, which had been tentatively designated "Saranyu," was renamed "Arcadia" by Dr. Benjamin Tromp, the head of the expedition's scientific team.
The exploration of Arcadia proceeded, first with probes and orbital surveys, then with manned landers. Work on a surface gate was initiated that same year, and the surface gate was first opened in 2047.
Arcadia has a diameter 12,102 km, a mass equal to .979 of Earth mass, an atmosphere with a surface pressure of .991 atm. Surface gravity is 1.012 G. Oxygen makes up 22% of the atmosphere by weight with nitrogen at 76% and 2% trace atmospheric gasses, including argon, neon and carbon dioxide.
Arcadia's surface is over 99% water. There is one major landmass, though this is quite small by Earth standard (by which the Arcadian landmass would be categorized as a large island.) The combined surface area of the main Arcadian landmass is approximately 390,000 square kilometers.
Arcadia's rotation gives it a 27.2 hour day. Arcadia orbits Luhman-16A at a distance of only 9.55 million kilometers, which places it inside the very narrow "life zone" of the relatively cool dwarf star. (For comparison, Earth's orbital distance from the Sun is approximately 150 million kilometers.) Arcadia's orbital period is approximately 37 Earth-days, or 32 Arcadian days, (a period of time which colloquially serves as an "Arcadian month.") Arcadia has an orbital eccentricity even lower than that of Earth (and thus a very circular orbit.) This, along with Arcadia's axial tilt of just over 9 degrees, leads to relatively undifferentiated seasons. There are three very small moons, (three small, captured asteroids, the largest only 18 kilometers across) that, from the surface, appear as bright, fast-moving stars.
Arcadia's landmass is roughly equatorial. Mean daytime temperatures range from an average low of 22 degrees C. (about 72 degrees F.) to an average high of 45 degrees C. (about 113 degrees F.), but particularly hot days can exceed 50 degrees C. (about 122 degrees F.) and particularly cold nights can drop into the high single digits (somewhat below 50 degrees F.)
Ravi, Arcadia's sun, has an overall luminosity is less than 1% that of Earth's Sun, but actual light levels on Arcadia are comparable to those of Earth due to Ravi's extreme proximity.
Arcadia's seas harbor extensive single-cellular microscopic alien life, much of which is oxygen-producing. To date, this native life has proven to be utterly biologically incompatible with any Earth life; Arcadian microorganisms cannot survive inside Earth creatures and cannot derive nourishment from or give nourishment to Earth life. To date, no native macroscopic or multi-cellular life has discovered on Arcadia.
Arcadia's landmass has so far been found to be utterly barren of native life. It is speculated that Arcadia's biosphere is fairly young and that it has not yet colonized Arcadia's land.
Arcadian sea water has a mineral content which is toxic to Earth life. Even when this water enters the water cycle and descends as precipitation (which is rare on the Arcadian landmass) it remains mildly toxic to Earth life. Thus, all water on Arcadia must be desalinated and/or filtered before being used by humans, Earth animals, or for Earth plants.
Arcadia has, to date, proven to be relatively mineral poor. There are no fossil fuels of any sort and no radioactive elements such as thorium or uranium (that could be used for nuclear power) have been discovered. Arcadia has, however, proven rich in iron and copper bearing ores, and some gold and silver has been mined on a successful commercial basis from copper-dominated silver and gold bearing ores.
Colonization of Arcadia commenced in 2047. Initial optimism about a "third habitable exo-planet" was quickly dimmed by Arcadia's harsh climate, but despite this (or perhaps because of it) Arcadia became a popular colonization destination for an assortment of political refugees from around the world, many seeking a place to escape from nations where their status had become marginal at best.
Arcadian population has since grown steadily by immigration and natural increase since the first colonization efforts in 2047. As of 2077, the planetary population stood at 6.7 million people. Of these, just under 500,000 are UEN-designated Economic and Political Refugees housed in UEN-constructed Safe Relocation Camps.
The largest single settlement is Redstone City, with a population of approximately 490,000.