Niago
The water world.
A warm, stormy ocean world around Alpha Centauri B, lit by a second sun. The largest colony outside Sol.
- Star
- Alpha Centauri B
- Gravity
- 1.0 g
- Population
- ~5 million
- Breathable
- Yes
Statistics
| Where it is | |
|---|---|
| Star | Alpha Centauri B |
| Designation | Alpha Centauri Bb |
| Star type | K1V orange dwarf, about half as bright as the Sun |
| Distance from Sol | 4.37 ly |
| Orbit | 0.69 AU, near the warm side of the habitable zone |
| Year | 220 days |
| Day | ~30 hours |
| Real-world status | Invented; searches haven't ruled out an Earth-mass planet in Alpha Centauri B's habitable zone |
| Size | |
| Type | Tropical water world |
| Radius | Earth-sized |
| Mass | Earth-sized |
| Density | — |
| Surface gravity (g) | 1.0 |
| Environment | |
| Atmosphere | Nitrogen-oxygen |
| Breathable | Yes |
| Temperature | Tropical across most latitudes, with very little seasonal change |
| Surface | ~95% ocean; volcanic island arcs and a few small plateaus |
| History | |
| First explored | ~2039 (first crewed survey of Alpha Centauri) |
| Colonised | 2,046 |
| People | |
| Population (2076) | ~5 million |
| Role | The largest colony outside Sol |
Climate
Niago receives about the same energy from its star as Earth does from the Sun. It is tropical across most latitudes, because a dark ocean absorbs more sunlight than land does, with frequent storms, warm seas, and very little seasonal change. Land is only about 5% of Earth's continental crust.
The second sun
Alpha Centauri A orbits B every 80 years at 11–35 AU. From Niago it shines as a brilliant second sun, a dazzling point hundreds to thousands of times brighter than the full Moon. For decades at a time, part of every night is lit by a soft yellow twilight. Niagoans track the 80-year cycle closely, and "Long Light" and "Deep Night" generations each have their own traditions.
Life
The oceans teem with native life that has evolved convergently into fish-like, octopus-like and crustacean-like forms. Much of it is edible. Many Earth species have also been introduced successfully.
Settlement
Early colonisation was led by East Asian nations, especially China and Japan. Their influence shapes the architecture (stilt cities, floating districts, terraced island towns), the language mix, food, and dominant customs.
Why Alpha Centauri B
The ideal was a star 5–7 ly from Sol, but the only stars in that range are Barnard's Star, whose surveyed planets are all too hot and small, and the Luhman 16 brown dwarfs. Alpha Centauri B is Sun-like enough for Earth-like conditions, and it is the nearest system with room for such a planet.
Trivia
The name Alpha Centauri Bb was briefly used in 2012 for a claimed hot planet that was later retracted.