What if Alpha Centauri has no planets?

[g.neuman]

You took him seriously? I would have thought the reference to "Endor" and "smashing" planets together to make one bigger, more perfect planet, might have been a clue.

LOL. I wish Mars was significantly bigger too (as do most astronomy buffs, I'd imagine), but I've never really taken it farther than "I wish Mars was bigger". Rearranging the inner solar system and smashing planets together hadn't really occured to me.

On the other hand, who knows what kind of technologies will be available to our decendents? We went from "Hey, this 'farming' idea looks like it might have some possibilities" to "One small step for a man, one giant leap for mankind" in less than 5000 years. Assuming nothing wipes us out, the people who live 10,000 or 20,000 years from now might well be able to rearrange the solar system to better suit the needs of our species. Venus and Mercury certainly aren't doing anyone any good where they are.

As for the thread's original question, any answers we get from missions like TPF and Darwin will be far from conclusive. Picking out an Earth-sized planet will be a chancy thing under even the best of circumstances, to say nothing about determining whether or not such a planet is actually habitable. Barring some dramatic and unforseen leap in technology, game designers and sci-fi authors alike will be safe in giving Alpha Centauri a hypothetical Earthlike world for some time to come.

Personally, I think future generations are likely to discover that most Earthlike worlds are the moons of gas giants anyway (which, unfortunately, would be virtually impossible for TPF to detect). The majority of other star systems don't seem to be arranged very much like ours; Jovian planets can and do occur in every conceivable orbit, from very close in to very far out. The presence of such planets utterly dominates the formation of the rest of the system in a variety of ways, so small rocky worlds in water orbits are probably not the norm. Judging by what we currently know, I believe our best bet for finding Earthlike worlds is to find gas giants in stable, circular water orbits and then hope they have a big moon or two.

Interesting topic!

 

[deanej]

Actually, current technology is not capable of detecting systems like ours. They could be very common, but we wouldn't know because we can't detect them.

 

[g.neuman]

Actually, current technology is not capable of detecting systems like ours. They could be very common, but we wouldn't know because we can't detect them.

Sure we can. Both 47 Ursae Majoris and OGLE-2006-BLG-109L are known systems that are quite similar to ours.

It's true that systems with hot jupiters (and other eccentric arrangements) are easier to detect using current technology; orbital distance and planetary mass largely determine how well the "wobble method" works. But the fact that most systems we've discovered using any method look very different from our own tells us that we're almost certainly not the norm. That's not to say that there aren't others out there. There will undoubedtly be some that are arranged like ours.

But not too long ago most astronomers believed that the arrangement of our solar system would be typical, if not outright definitive. That's turned out not to be the case.

 

[Robert Can't]

You mean like... a communal "hive" mind, based upon fungus spread quite literally across an entire planet? It doesn't even have a concept for lannguage, let alone communication... there are no other "minds" in its history so there would be no need to communicate. (ps "language" is a subset of "communication") Such a creature would have to learn the very concepts of communication and language from the humans it encounters. The initial "get to know you" period could be quite traumatic for the humans.

That sounds like Enders game orson scott card

 

[deanej]

Sure we can. Both 47 Ursae Majoris and OGLE-2006-BLG-109L are known systems that are quite similar to ours.

It's true that systems with hot jupiters (and other eccentric arrangements) are easier to detect using current technology; orbital distance and planetary mass largely determine how well the "wobble method" works. But the fact that most systems we've discovered using any method look very different from our own tells us that we're almost certainly not the norm. That's not to say that there aren't others out there. There will undoubedtly be some that are arranged like ours.

But not too long ago most astronomers believed that the arrangement of our solar system would be typical, if not outright definitive. That's turned out not to be the case.

47 Ursae Majoris is still two super-Jupiters, just not as close (closer than Jupiter is to the sun, though). The planets in OGLE-2006-BLG-109L are both gas giants as well. We still don't have the technology to detect planets the size of Earth (though super-Earths have been discovered). I'm sure we'll detect a few systems like ours when we have the technology.

Actually, a system of Earth-sized planets has been discovered... around a pulsar.

 

[g.neuman]

47 Ursae Majoris is still two super-Jupiters, just not as close (closer than Jupiter is to the sun, though). The planets in OGLE-2006-BLG-109L are both gas giants as well. We still don't have the technology to detect planets the size of Earth (though super-Earths have been discovered). I'm sure we'll detect a few systems like ours when we have the technology.

Well, by "similar to ours" I simply meant that the jovian planets have orbits that are 1) essentially circular, and 2) far enough from the primary to allow for the possibility of terrestrial planets closer in. Of course we can't yet detect whether or not such planets are actually there; that's what missions like TPF and Darwin are all about.

If I was unclear about that earlier, I do appologize. When I said "like ours" I should have said "like ours according to what we know so far".

Actually, a system of Earth-sized planets has been discovered... around a pulsar.

Yep, read about that one a long time ago. They might be the remains of gas giant planets that were mostly vaporized by the supernova explosion that created the pulsar. I can't imagine that there'd be anything left of a close-orbiting terrestrial.

 

[GeoModder]

P.S In SMAC The Planet, after the fusion with the human minds , appears in the end message making a Dyson sphere

No, it's just the planet becoming completely illuminated. In fact, the last popup still thanks about humans roaming its planetary garden.
There is an 'encapsulation' project under construction in this epilogue, but I don't think it involves Chiron itself.

 

[GeoModder]

47 Ursae Majoris is still two super-Jupiters, just not as close (closer than Jupiter is to the sun, though). The planets in OGLE-2006-BLG-109L are both gas giants as well. We still don't have the technology to detect planets the size of Earth (though super-Earths have been discovered). I'm sure we'll detect a few systems like ours when we have the technology.

It's probably only one super-jupiter. The second jovian is a quarter less massive then Jupiter according to measurements.

 

[r_rolo1]

No, it's just the planet becoming completely illuminated. In fact, the last popup still thanks about humans roaming its planetary garden.
There is an 'encapsulation' project under construction in this epilogue, but I don't think it involves Chiron itself.

I never said that the encapsulation involved Chiron

But anyway, a real Dyson Sphere would need materials and techniques that we simply can't even see in the horizon. A constelation of statites ( a object maintained in place by the equilibrium of light pressure + solar wind vs solar gravity ) or Dyson rings, would be far more easy to acheive.

 

[Wodan]

...a object maintained in place by the equilibrium of light pressure + solar wind vs solar gravity

Right. What could possibly go wrong?

 

[r_rolo1]

No more than living in a huge rock with thousands of objects bigger than a mile passing by

 

[Wodan]

No more than living in a huge rock with thousands of objects bigger than a mile passing by

Well the difference is that we weren't living here for the several BILLION years it took things to settle down.

So, if you want to make your Dyson sphere, and then come back in a couple billion years, then yeah, it seems workable.

 

[r_rolo1]

Well the difference is that we weren't living here for the several BILLION years it took things to settle down.

Things are settled down? Not according with Shoemaker-Levy 9

 

[Wodan]

"Settled down" to the point that humans can survive.

 

[r_rolo1]

If we got a hit of only one of the fragments of Shoemaker Levy 9, I highly doubt that we would be talking about it And that is one of those things that we can get certain off: we'll get hit, sooner or later, by a object of that size.

 

[NintendoTogepi]

If we got a hit of only one of the fragments of Shoemaker Levy 9, I highly doubt that we would be talking about it And that is one of those things that we can get certain off: we'll get hit, sooner or later, by a object of that size.

Do you REALLY think humanity would go extinct from a asteroid?

I bet a million bucks at least a million of us would survive

That is, assuming the asteroid/comet isn't so big that pretty much destroys the Earth

 

[bestbrian]

To hell with an asteroid impact; once Yellowstone blows, it's game over.

 

[GeoModder]

Right. What could possibly go wrong?

Nukes!

To hell with an asteroid impact; once Yellowstone blows, it's game over.

Not to mention La Palma sliding into the ocean.

That is, assuming the asteroid/comet isn't so big that pretty much destroys the Earth

An object large enough to physically destroy Earth would have to be planet-sized.

 

[NintendoTogepi]

I think it will take quite a bit to exterminate humanity, I think even if the killer asteroid slammed into Earth, La Palma slid into the ocean and Yellowstone erupted at the same time there would still be PLENTY of us, just about 6 billion less

 

[GeoModder]

Taking into account that in only a few years we'll be with 7 billion, 6 billion less shouldn't be much of a hinderance.