2017-02-27 09:09:48 UTC
unlikely for that planet, although rocky and thus in that respect Earthlike, to
be a home to alien life.
That, however, does not make it entirely dull, boring, and uninteresting.
The Alpha Centauri - or Rigil Kentaurus (the IAU having made that individual
name for that star official) - system consists of Alpha Centauri A, a G2 star,
orbited by Alpha Centauri B, a K1 star, in an orbit the radius of which varies
from that of Pluto around our Sun to that of Saturn, and Proxima Centauri with a
period of 550,000 years at a distance of 15,000 AU (this being only very
recently established - previously, it was not certain if it really orbited Alpha
There's no direct evidence of an Oort Cloud around Alpha Centauri, but the Oort
Cloud is so far out that the system being a multiple star system shouldn't
mitigate against having one. Alpha Centauri B, though, might well mean there's
no Kuiper Belt in that system, as well as no gas giants, so the system may be
short of volatiles.
The interest of Proxima Centauri b stems from the fact that Proxima Centauri,
being an M6 star, is going to be around for another ten trillion years before it
goes off the Main Sequence. And when it *does* do so, it won't swell up to
become a red giant, it will just fade down into a white dwarf.
At 15,000 AU away from the other two stars in the system, when Alpha Centauri A
and B become red giants, that should be nothing more than an interesting
spectacle from the vantage point of Proxima Centauri b. Particularly as any
people living there would presumably live underground, as terraforming, given
that Proxima Centauri is still active as a flare star, would be wasteful.
So a colony on Proxima Centauri b, say of giant hollow domes within the bedrock,
receiving sunlight concentrated with mirrors sent down through narrow vertical
shafts to them, could be a long-term home for humanity. One that has a
relatively convenient location, given that it orbits the star that is the
closest to us.
Thus, sometime in the next few billion years, it might not be too bold to
imagine that humanity would reach a point where it could send a sublight
generation ship - or something involving uploads, frozen embryos, and artificial
wombs - to that system in order to ensure a more long-term future for humanity.