Damn, I love this place.
Humans do not pass out at 5g.
Well, I suppose they could…depends on the person and the situation.
Fighter pilots regularly pull 9g or so. But then they have flight suits that squeeze them in various ways to help them and they are trained to resist the effects via clenching and such.
Still, while 5g would be debilitating to a human it is not so much to think no life could evolve in that environment.
Besides, as has been noted in this post this planet would actually have a gravity of around 1.7g. To us a bother but not a show stopper. Life (in theory) could live in that environment (not saying it does, just that it could).
All I’m hearing is “Christmas every day!”
But the thing is, science is based on observations, not on what you happen to think.
Those of you wanting to build a .05C probe, consider the following:
Building a probe which would physically approach the planet would essentially be a futile effort because of the technology curve that would transpire before it reached the planet. In 200 years, with serious efforts in spacefaring technology, it is possible new probes (or perhaps even manned spacecraft) could/would be built which would catch up to the Longshot probe before it ever reached its destination. (No, not talking magical FTL drives, either.) Or even solar-system-based remote observatories capable of resolving images that far away.
Yeah, I read some book about this long ago except it was talking about generation ships. The problem is that the first generation ships that are sent are passed by newer/faster generation ships to a certain destination.
That would suck if you had been traveling for hundreds of years and when you finally reach the planet you find out that humans have colonized it 50 years before you.
It would be utterly ridiculous to pick a planet to colonize in the present state of our technology. If we currently know about 492 exoplanets, we should know about tens of thousands of them within a couple of decades:
The first thing we need to do is learn much more about exoplanets. Then we can think about which ones would be the most Earth-like.
Are there any closer star systems that haven’t been studied as closely at this one, that may harbor a “goldilocks zone” and suitable planetary bodies?
I don’t know, it might be nice to land, step out, and have a mocha latte waiting for you from the newest Starbucks franchise.
Realistically, though, generation ships are about as unlikely as Noah and his animals marching two-by-two onto the Ark for forty days and nights. Barring some kind of indistinguishable-from-magic propulsion technology, the energy requirements to send any plausible colony payload to even the nearest stars in a conceivable timeframe are literally, well, astronomical; comparable to moving small planets around. If and when we actively explore beyond our system, it will likely be by proxy; self-repairing and self-replicating probes with the best approximation of cognitive intelligence as possible. It is also unlikely, regardless of the distribution of rocky worlds in habitable zones, that we’ll find a planet that is suitable for human occupation on the surface as is, particularly in the existence of a breathable oxygen-rich atmosphere. In terms of expanding civilization beyond Earth’s surface, it makes far more sense to build robust solar-orbiting habitats than to search for or attempt to create suitable planetary conditions.
Stranger
Our best hope for colonizing beyond our star system would be to build space habitats around Sol and then sit tight for a few hundreds of thousands or millions of years until another star happens to make a close pass. Hopefully the new star will have its own complement of asteroids and comets with which to build new habitats. After a few billion years our descendants may be all over the galaxy.
“A close pass” may still be several light years distance. We’re hardly lacking in material or energy; even a conservative estimate on the amount of material per person required for sustainable habitat will allow the loose components of the Solar system (comets, asteroids, and small moons) to serve as construction and sustenance materials to support a population of several hundred billion, and as for energy, it is freely wasted by our central body to the tune of four hundred trillion terajoules per second. There is no foreseeable logistical reason as a civilization that we would ever have to go beyond the Solar system; the reason to do so is scientific curiosity and to safeguard our cultural and genetic heritage (such as it may evolve into over a period of millions or billions of years) by dispersing it across multiple star systems.
Stranger
So, the general consensus seems to be that direct exploration of exoplanets is a long, long way off.
So, the next best thing would be better observation techniques. Would it be at all feasible, in the foreseeable future, to build telescopes (either ground or space-based) that could directly image exoplanets with some measure of visual detail?
Obviously, creating detailed topographical maps of their surface would be out of the question, but even an extremely low-resolution image of a planet would probably give us a huge amount of information about it, and allow us to make far more educated guesses about the presence of life.
Doesn’t every star have a goldilocks zone? For a star like our sun, it’s around 1AU out. For a red dwarf like Gliese 581, it’s much closer. For equal comfort you stand close to a tiny fire and stand far away from a bonfire.
Watching the NSF webcast yesterday, I understand that the planet hunters are not quite yet capable of detecting an Earth-sized planet orbiting an Sun-sized star using the radial velocity (doppler) technique. They continue to make great strides but to find a second “Earth” is going to require velocity measurements on the order of a few cm/s and the current limit is just under 1m/s. Still, to find a Gliese 581g so quickly and so close leads astronomers to believe that a large percentage of stars (10% to 20%) contain similar systems of planets. Even if we’re really pessimistic and it’s just 1% that would still represent over a billion “Earths” in our galaxy alone.
I think that’s what I’m asking - are there closer systems that could be studied to find similar planets to Gliese 581g, but that are much closer, allowing for “easier” investigation?
According to this Wiki page Epsilon Eridani is the nearest star we have detected a planet at and that star is 10.5 light years away (so about half as far a the one in the OP).
Still, even if Proxima Centauri (the closest star to us) had planets you are still talking about 4.2 light years. That’s 24,690,246,000,000 (24.7 trillion miles). Our fastest probe would take 73,000 years just to make that trip.
Till we find a way to get to substantially faster speeds we are pretty much stuck in our solar system.
Well, we’re already a few light years from the nearest star. Hopefully, closer passes are within our future. “Close” would be “close enough to get there with a reasonable expenditure of the resources at hand”. Light-weeks? Light-days? I don’t know.
In case someone out there happens to do galaxy modeling, it would be interesting to know what kind of “close” passes might be likely for our sun within, say, the next billion years.
As for why - Malthus has long arms. It won’t take long to reach hundreds of billions, and some faction at the time may decide to risk the frontier.
What could we send them that would tell them more about us than the episodes of Cheers and America’s Funniest Home Videos they are watching now? 
Very, very rare. Although we’re in a fairly dense local neighborhood of stars (which are largely traveling in the same relative velocity and in a loose lazy orbit around their common barycenter, we’re generally in a sparse area at the outer part of our spiral arm, though that may because we can’t see many of the M-type stars (but this wouldn’t be suitable to colonize anyway, being smaller and much less luminous). I can’t find a cite right offhand and any answer would still be pretty speculative, but I doubt a star would pass within 1000 AU more than once every few million years if that, and probably at velocities that would be prohibitive to transfer to regardless. The problem, after all, isn’t just the distance, but also the speed you have to gain or lose in order to get from one system to another; a system that flies by at couple hundred km/s is still unachievable by any conventional propulsion technology.
Stranger
There are 86 closer systems but we do not yet have the capability of finding all of the planets because we can only doppler shifts beyond a certain magnitude and the eclipse technique (Kepler) can only find planets that happen to pass in front of their star from our POV.
Right, all stars have a “Goldilocks zone”, but our planet-hunting techniques work best for planets that are close in to their star, so the only planet we’ve found in a Goldilocks zone so far has been one around a very small, cool star. We couldn’t yet find a planet in the Goldilocks zone of, say, epsilon Eridani, tau Ceti, or sigma Draconis using the Doppler method. We could, in principle, find one using an eclipse method like the Kepler satellite uses, but only if we’re lucky: Only about 1% of solar systems happen to be aligned the right way for that to work.