Thank you for all those informative links - much appreciated.
While the Proxima Centauri travel video was interesting, a part of it was potentially misleading. A planet that close to its parent star would in all probability be tidally locked so that one hemisphere would permanently face the star while the other hemisphere would be in total darkness. Given that planet's mass, it could very well be geologically active like Venus and Earth are although lack of fast rotation may not bode well for a strong and protective magnetic field (compare the Earth & Jupiter fas rotators)
If the conditions on the surface are clement and favourable for life, then things can start to get interesting. The star's spectrum and emission peak and atmospheric absorptivity all help to determine the best photosynthetic colour for maximum efficiency and in the case of a dim red star, any plant leaves are likely to be black in colour. The nearest Earth equivalent is 'purpurea' plants, shrubs and trees (I don't like them at all!).
Originally Posted by atg:
“I agree that talking in those timescales is pretty meaningless, but whatever our descendents look like then, they would still need somewhere to live. One thing though, proxima centauri is already a red dwarf, how long does it have and would that planet still be in a habitable zone, as planetary orbits are essentially chaotic anyway and this one is very close to the star and you would think would be easily perturbed? Also, it would probably be a better idea to move there before our sun dies, not after.
I wonder if Hawking and his colleagues knew about this when they suggested the micro probe mission earlier this year.
And, how close would the JWT be to being able to image this directly?”
Basically, the smaller and redder a star is, the longer it lives. Theoretically, a small red dwarf M class star might potentially live for hundreds of billions of years and even in the trillions range (Proxima Centauri itself might possibly last 4 trillion years). Orange K class stars (like Alpha Centauri B) might live from 15-30 billion years (I like them) while larger G class stars like Alpha Centauri A and our Sun live for about 10 billion years. There appears to be trend that the smaller the star is the more likely it is to flare up and flaring is more common in young stars.
Originally Posted by Assa2:
“Of course it's ridiculous to talk about humans moving to this prospective new home when the sun eventually makes the Earth uninhabitable, but for a news cycle that's exactly what everyone wants to be talking about in order to get noticed.
That said if humanity survives the next couple of centuries and figures out how to live off Earth and colonise the solar system then there's no limiting factor to suggest our sepcies or what ever we become cannot survive indefinitley so finding these planets is crucial so that we know that eventually, when the solar system becomes over-crowded and resources start to run low there's somewhere else 'close' by to go.
I personally think this is great news right now as there's long been a deficiency in funding towards next-generation propulsion systems for deep-space exploration. While we're happy sending probes out to the planets we're happy with long-duration missions but if we want to take a probe mission to this new planet seriously we're going to need a new way of accelerating it to a reasonable proportion of c. The by-product being hopefully faster inter-planetary missions which would suit manned missions much more.”
The exoplanets in the habitable zones around Proxima Centauri (4.2 light years away) and Wolf 1061 (14 light years away) provide an excellent incentive for humanity to get out of the solar system even if only by robotic probes initially such as the Starshot Project and I very much hope that other similar nearby planets are found.
In terms of human exploration, the VASIMR and NERVA engines are credible ways of getting around within the solar system but as for travel to the stars, the only half way decent attempt is the Bussard Ramjet and variants thereof.