It could be that at least one-third of the star systems in the Universe are multiple stars (binary or more). Can complex life form in a planet orbiting the Binary star system ?
Planetary orbits in a binary system might not be stable long enough for complex life to evolve. Stable orbits in the habitable zone of a binary system might be rare, lowering the probability of the evolution of complex life forms. BTW: Asimov (or maybe Clark) once wrote an article suggesting that from a planet orbiting one star of a binary system, the other star would appear to be a very bright star rather than appearing to be a small Sun.
A planet could be ina stable orbit, giving time for intelligent life to evolve, it the binary stars are very close or very far apart, as in the distance from the Sun to Uranus or Neptune. It is in the intermediate realm that instability becomes a problem.
John M The following is a valid statement. The operative phrase is Could Be. A binary system decreases the probability of a stable orbit. Judging from the only actual data we have (Earth), it seems to take about a billion years for life to come into existence & evolve to a complex level. It took over 3 billion years for the evolution of intelligent life. That is a long time for a planetary orbit to be stable. Note that the planets in our solar system have approximately circular orbits. Our orbit might not be stable for even a billion years if the orbits of planets farther from the sun were much more elliptical, If either Jupiter or Saturn had elliptical orbits, Earth’s orbit would probably not be stable long enough for intelligent life to evolve. Note that a single planet orbiting one star in a binary system might be stable for a long time. If there are several planets orbiting that star, the orbits of the outer planets would probably be affected by the other star in the system and/or by planets orbiting the other star. The planets more distant from the star would very likely have elliptical orbits, destabilizing the orbits of the inner planets. Life is likely to evolve in a solar system in less than a billion years, but the evolution of intelligent life seems to require far more time. The odds are against intelligent life in a binary system.
Wouldn't the distance between the stars play a big role in whether or not planets can have a stable orbit around either star? Furthermore, what about the star's individual characteristics? The distance of either star's Goldilocks zone would vary - closer in for a cooler star, farther out for a hot star. I remember reading somewhere - a long time ago, granted - that Alpha Centauri A and B are sufficiently far apart to (theoretically) permit for planets in a stable orbit around both A and B. Now I may be mistaken here so someone please correct me if necessary: One problem in my mind is that in a binary system there may be a higher likelihood of rogue comets/asteroids/planetoids due to the gravitational tug-of-war between the stars outside the stable orbits of each. This could increase the chance of cosmic impacts which would make it more difficult for complex life to survive in the long term.
Hm, bit of a temper there? If you're that passionate about it, PM a mod and ask to consider a merge. Failing that and seeing as this thread was created a month ago without intervention, I consider this a different discussion: Strictly speaking, I see that one is talking about whether a planet can be habitable, while the other is talking about whether complex life can occur. They are certainly related, though somewhat different. Until a mod decides whether or not to merge the discussions, I would like to postulate that should a binary system hold habitable worlds, the presence of two stars may result in an increased number of collisions. This would in turn reduce the chance of complex life surviving for an extended period of time. As it stands, we are relatively protected in a single star system as there are no tidal forces between stars and are additionally protected by the gas giants.
I did a long time ago, they did not care. You don't think another star would be as effective or even more so than Jupiter?
There is a big difference between Jupiter & another star. The above was in the context of viewing Jupiter as protecting Earth from impacts of asteroids & other objects. Jupiter is overwhelmed by Sol. A single star solar system like ours is dominated by the huge central mass (Sol). Such a system tends to have almost circular orbits & is very stable. In a binary system, each star would have noticeable effects on the orbits of planets in the other solar system. The outer planets of one solar system could have noticeable effects of the planets of the other solar system. I could be way wrong in my guesstimates which suggest that the members of a typical binary system are separated by light hours or light days rather than light years as in the case for the distance between Sol & the Centauri stars. A small perturbing effect over a period of millions of years could destabilize a solar system. It is my understanding that planets of both members of a binary pair would orbit in approximately the same plane, just as all the planets in our system orbit in approximately the same plane (I think Pluto & perhaps Neptune deviate most from the plane of the ecliptic). The outer planets of the two solar systems would occasionally be at their closest distance to each other. When closest to each other, there would be a small perturbing effect. This would tend to make circular orbits become elliptical over a period of 50 to 100 million years. When an outer planet in an elliptical orbit is closest to the star it is orbiting, it is also closer to the inner planets, interfering with their orbits. Perhaps a simulator could estimate the stability of planetary orbits in a binary system. My guess is that few binary systems would remain stable for as much as 1-2 billion years. Of those that were stable for 3-5 billions years, some would not have planets in the habitable zone. Of course we are dealing with probabilities, which do not rule out the possibility of complex life forms in a binary system. Due to my view of the prevalence of intelligent life in the universe, I would not expect more than a few examples of it in solar systems of binary pairs. BTW: Contrary to most who think about such issues, I do not expect more than 1-2 other intelligent species in our galaxy & would not be surprised if it were discovered that we are the only intelligent species in our galaxy. I expect many galaxies to be void of intelligent life forms, & expect very few or none to have more than1-2 intelligent species. The issue of the prevalence of intelligent life in the universe has been the subject of at least 2-3 threads at this forum. This is not the place to rehash the debates in those threads. Search for & perhaps revive one of those other threads.
There ought to be two threads any time we are talking about binary stars.Please Register or Log in to view the hidden image!
