Houston, Republic of Texas — February 21st 2173. The second of mankind’s interstellar probes has returned from Alpha Centauri, where it made a spectacular discovery: the existence of not only one, but two human-inhabitable planets in that system.
The probe emerged from Hyperspace almost exactly on target and entered a parking orbit around Mars while transmitting data back to mission control. “The data we did get back immediately showed us that our wildest dreams had been eclipsed,” Mission managers and representatives of the Colonial Authority said in a joint press conference today.
The Alpha Centauri system, of which Proxima Centauri is a distant companion, consists of two stars: Alpha Centauri A, an almost identical two to our sun, and Alpha Centauri B, which is more orange in color. Both stars possess individual star systems, with a total of 16 systems. Both of the earthlike “Garden” worlds orbit around Alpha Centauri A. Both of them, initial data suggests, support life, but in neither case has it evolved very far.
“There’s plentiful plant life on the inner of two garden worlds, and probably early land-dwelling animals. Ohe second garden world has even more primitive life; it hasn’t conquered land now.”
In addition to the large distance of the world to its sun – at 1.71 it orbits at the outer edge of the Habitable Zone – Planetologists pointed at the absence of moons orbitting the further Garden world as a likely cause: “Without large moons, conditions on Earthlike planets are more chaotic, and we suspect this may have a negative impact on the evolution of higher species.”
In detail, the composition of the Alpha Centauri A system is:
- Hothouse World (0.2 AU): 11000km diameter, density 0.8, Gravity 0.73. Massive atmosphere, no water, 1 moon.
- Desert World (0.3 AU): 4000km diameter, density 0.9, Gravity 0.3. Thin atmosphere, no water.
- Rock (0.42 AU): 2000 km diamteer, density 1.3, gravity 0.22. Vacuum, minor ice deposits,3 moons.
- Hothouse World (0.67 AU): 15000 km diameter, density 0.6, gravity 0.75. Dense atmosphere, no water, 3 moons.
- Garden world (1.01 AU): 11000 km diameter, density 0.8, gravity 0.73. Dense atmosphere, 60% oceans. 1 moon.
- Garden world (1.71 AU): 12000 km diameter, density 0.9, gravity 0.9. Dense atmosphere, 80% ice sheets.
- Failed Core (2.4 AU): 8000 km diameter, density 0.3, gravity 0.2. Thin atmosphere, 80% ice sheets. 1 moon.
- Failed Core (3.6 AU): 24000 km diameter, density 0.2, gravity 0.4. Dense atmosphere, 60% ice sheets. 2 moons.
Alpha Centauri B’s system is less promising. There are two Mars-like desert worlds in its habitable zone, both lifeless, and one hothouse slightly larger than earth. All three could be terraformed but lack significant water reserves.
- Rock (0.3 AU): 1000 km diameter, density 1.2, Gravity 0.1. Vacuum, minor ice deposits.
- Hothouse (0.48 AU): 14000 km diameter, density 0.9, gravity 1.05. Dense atmosphere, no water.
- Desert world (0.62 AU): 4000 km diameter, density 0.9, gravity 0.3. Thin atmosphere, minor ice deposits, 1 moon.
- Desert world (1 AU): 10000 km diameter, density 0.4, gravity 0.33. Standard atmosphere, minor ice deposits.
- Ice Ball (1.3 AU): 4000 km diameter, density 0.3, gravity 0.1. Vacuum. 60% ice sheets. 1 moon.
- Ice Ball (2.07 AU): 2000 km diameter, density 0.5, gravity 0.08. Vacuum. 50% ice sheets. 2 moons.
Unless Barnard’s Star holds any surprises, the discovery of two habitable planets at Alpha Centauri make the binary system the destination for mankind’s first manned interstellar expedition, which is currently bein prepared by an international team under the coordination of the Colonial Authority.
The United States, China, Europe, Russia, Brazil and Indonesia immediately announced that they intend to set up colonies on the as-yet unnamed worlds, and other nations are expected to follow soon.