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New planet discovered orbiting our nearest neighbor.

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Kurgan
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21 Oct 2012, 12:31 pm

DeaconBlues wrote:
Actually, Kurgan, there's some evidence for the proposition that life evolved several times on this world, but was wiped out most of those times by asteroidal and cometary impacts. The early Solar system was not a very comfortable place to be...


Then I'll take back my statement. Life probably originated once, but might have originated several times. The very fact that inanimate organic matter doesn't evolve into "life" anymore or that life with different origins might have been killed off many times very early further suggests that life in the universe is rare, though.

There's only a small window in a planet's lifetime that life can originate in and for simple life forms to improve to more complex life forms, the initial conditions get progressively more strict. While we're probably not alone in the universe (just like our Sun is not the only star with planets), life does not develop on most planets capable of sustainng it within the possible timeframe and it's probably rare.



Last edited by Kurgan on 21 Oct 2012, 12:35 pm, edited 1 time in total.

Kurgan
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21 Oct 2012, 12:34 pm

Fnord wrote:
ruveyn wrote:
DeaconBlues wrote:
Actually, Kurgan, there's some evidence for the proposition that life evolved several times on this world, but was wiped out most of those times by asteroidal and cometary impacts. The early Solar system was not a very comfortable place to be...
Please provide references. Preferably from refereed scientific journals. ruveyn

What?

The History Channel isn't good enough?

:wink:


In the 1990's when these channels gave us documentaries with detailed models, interviews with respected scientists and so on, it might have been. Nowadays, these channels are more about little Honey Boo Boo, white trash mothers and all that.



DerStadtschutz
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21 Oct 2012, 1:04 pm

Jono wrote:
I've just read this article about the possible discovery of a planet orbiting Alpha Centauri B. It's unfortunately too close to the star to be in the habitable zone, however given that a planet of similar size further away would of had too small of an effect on the star to be detected by the same method, there could be other planets in the Alpha Centauri system as well. Since the Alpha Centauri system is a triple star system, I guess you could think that this planet has three suns. Although technically, Alpha Centauri B is the sun because that's the one it's orbiting. Here's the news article:

http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?_r=1&


Quick question... How do we know it's too close to be habitable? Like... are you aware of the fact that certain fungal spores are capable of surviving the vacuum of space? We assume that all life MUST be like life on earth, which isn't surprising, as it's the only life we know for sure exists, but at the same time, we need to understand that if there was ever life on mars, it would have adapted or just been suited for the conditions on mars. Just because no earth creatures could live on a planet doesn't mean it can't possibly be inhabitable. It just means it can't be inhabited by earth-born creatures.



Jono
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21 Oct 2012, 9:29 pm

DerStadtschutz wrote:
Jono wrote:
I've just read this article about the possible discovery of a planet orbiting Alpha Centauri B. It's unfortunately too close to the star to be in the habitable zone, however given that a planet of similar size further away would of had too small of an effect on the star to be detected by the same method, there could be other planets in the Alpha Centauri system as well. Since the Alpha Centauri system is a triple star system, I guess you could think that this planet has three suns. Although technically, Alpha Centauri B is the sun because that's the one it's orbiting. Here's the news article:

http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?_r=1&


Quick question... How do we know it's too close to be habitable? Like... are you aware of the fact that certain fungal spores are capable of surviving the vacuum of space? We assume that all life MUST be like life on earth, which isn't surprising, as it's the only life we know for sure exists, but at the same time, we need to understand that if there was ever life on mars, it would have adapted or just been suited for the conditions on mars. Just because no earth creatures could live on a planet doesn't mean it can't possibly be inhabitable. It just means it can't be inhabited by earth-born creatures.


When we talk about the the habitable zone, we're mostly talking about possibly habitable for life as we know it. The habitable zone is taken to be the region of a solar system where there could be liquid running water on the planet's surface, not too hot or too cold.

Incidentally, we already know about life that can exist in extreme conditions, the so-called extremophiles. However, it's hard to imagine that even they (or organisms similar to them) could survive at the temperatures that the surface of Alpha Centauri Bb is supposed to be. I don't think that the complex chemical reactions necessary for any form of life would be possible at those temperatures.



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21 Oct 2012, 11:57 pm

DerStadtschutz wrote:
Quick question... How do we know it's too close to be habitable?

First, its orbital period equates to an orbital radius of only 0.4 AU.

Second, this puts its surface temperature at around 1200 degrees C (about 2200 degrees F), which is hot enough to melt rocks. At that level of heat, organic compounds are broken down into their simplest forms.

Third, a world that hot and that close to its star would have no atmosphere -- it would all have been blown away millions of years ago. This means no water, either.

Finally, the world would be bathed in intense radiation, which has a tendency to disrupt and destroy all life processes. An airless, waterless, radioactive ball of lava would be extremely unlikely to have anything with the slightest resemblance to life, not matter how far you stretch the definition.

Therefore, the simplest explanation is that conditions on Alpha Centauri Bb are so inhospitable to life that life could not possibly exist there, regardless of what you may have seen on Star Trek or the History Channel.


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DerStadtschutz
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22 Oct 2012, 12:33 am

Fnord wrote:
DerStadtschutz wrote:
Quick question... How do we know it's too close to be habitable?

First, its orbital period equates to an orbital radius of only 0.4 AU.

Second, this puts its surface temperature at around 1200 degrees C (about 2200 degrees F), which is hot enough to melt rocks. At that level of heat, organic compounds are broken down into their simplest forms.

Third, a world that hot and that close to its star would have no atmosphere -- it would all have been blown away millions of years ago. This means no water, either.

Finally, the world would be bathed in intense radiation, which has a tendency to disrupt and destroy all life processes. An airless, waterless, radioactive ball of lava would be extremely unlikely to have anything with the slightest resemblance to life, not matter how far you stretch the definition.

Therefore, the simplest explanation is that conditions on Alpha Centauri Bb are so inhospitable to life that life could not possibly exist there, regardless of what you may have seen on Star Trek or the History Channel.


I don't even watch star trek OR the history channel; or any TV really, for that matter. All we can base it on is the life that's here on earth. Well, I would imagine that life NOT from earth would be adapted to NOT earth conditions... How can you honestly be so arrogant as to propose to know what the hell is out there, so far away that there's no chance you'll ever see it in your lifetime? I'm not saying there IS life there, I'm simply saying, you don't friggin' know. And I'll say this again: SOME SPORES CAN SURVIVE THE VACUUM OF SPACE. Fungus is a form of life... So if life can live in a f*****g vacuum, I'd imagine there are some other extreme conditions it can live in too.



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22 Oct 2012, 12:39 am

Jono wrote:
DerStadtschutz wrote:
Jono wrote:
I've just read this article about the possible discovery of a planet orbiting Alpha Centauri B. It's unfortunately too close to the star to be in the habitable zone, however given that a planet of similar size further away would of had too small of an effect on the star to be detected by the same method, there could be other planets in the Alpha Centauri system as well. Since the Alpha Centauri system is a triple star system, I guess you could think that this planet has three suns. Although technically, Alpha Centauri B is the sun because that's the one it's orbiting. Here's the news article:

http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?_r=1&


Quick question... How do we know it's too close to be habitable? Like... are you aware of the fact that certain fungal spores are capable of surviving the vacuum of space? We assume that all life MUST be like life on earth, which isn't surprising, as it's the only life we know for sure exists, but at the same time, we need to understand that if there was ever life on mars, it would have adapted or just been suited for the conditions on mars. Just because no earth creatures could live on a planet doesn't mean it can't possibly be inhabitable. It just means it can't be inhabited by earth-born creatures.


When we talk about the the habitable zone, we're mostly talking about possibly habitable for life as we know it. The habitable zone is taken to be the region of a solar system where there could be liquid running water on the planet's surface, not too hot or too cold.

Incidentally, we already know about life that can exist in extreme conditions, the so-called extremophiles. However, it's hard to imagine that even they (or organisms similar to them) could survive at the temperatures that the surface of Alpha Centauri Bb is supposed to be. I don't think that the complex chemical reactions necessary for any form of life would be possible at those temperatures.


I think the key phrases here are "as we know it," and "supposed to be." We don't really know how hot anything is out there, because we haven't been there, and we don't have thermometers there. I think it's a bit arrogant to suggest that we know when we have no basis for knowledge other than our own planet and solar system. And in all honesty, we don't really even know a whole lot about our own solar system. Far too often, we humans assume things and then present them as facts when nobody really KNOWS.



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22 Oct 2012, 5:20 am

DerStadtschutz wrote:

I think the key phrases here are "as we know it," and "supposed to be." We don't really know how hot anything is out there, because we haven't been there, and we don't have thermometers there.


The temperature can be determined by the frequency of the light emitted. Look up black-body radiation when you get a chance. Hot stuff glows red then orange then white then blue then goes into the x-ray and gamma ray range.

ruveyn



DerStadtschutz
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22 Oct 2012, 5:51 am

ruveyn wrote:
DerStadtschutz wrote:

I think the key phrases here are "as we know it," and "supposed to be." We don't really know how hot anything is out there, because we haven't been there, and we don't have thermometers there.


The temperature can be determined by the frequency of the light emitted. Look up black-body radiation when you get a chance. Hot stuff glows red then orange then white then blue then goes into the x-ray and gamma ray range.

ruveyn


But wouldn't the color also be affected by what the burning object is made of? Also, that might help determine how hot the star is, but how do we know how much of that heat gets transferred to the planet, or that absolutely no life can live under those conditions? For all we know, whatever lives there doesn't need an atmosphere. Maybe there's subterranean life. I'm not saying that there IS life there, and I'm not saying that any of you are absolutely wrong. I'm simply suggesting the possibility that we don't know everything.



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22 Oct 2012, 9:35 am

DerStadtschutz wrote:
ruveyn wrote:
DerStadtschutz wrote:

I think the key phrases here are "as we know it," and "supposed to be." We don't really know how hot anything is out there, because we haven't been there, and we don't have thermometers there.


The temperature can be determined by the frequency of the light emitted. Look up black-body radiation when you get a chance. Hot stuff glows red then orange then white then blue then goes into the x-ray and gamma ray range.

ruveyn


But wouldn't the color also be affected by what the burning object is made of? Also, that might help determine how hot the star is, but how do we know how much of that heat gets transferred to the planet, or that absolutely no life can live under those conditions? For all we know, whatever lives there doesn't need an atmosphere. Maybe there's subterranean life. I'm not saying that there IS life there, and I'm not saying that any of you are absolutely wrong. I'm simply suggesting the possibility that we don't know everything.


Regardless, we have a pretty good understanding of physics and chemistry. The temperature of the planet can be known from it's proximity to the star. Notice that I did mention extremophiles in my last post? Regardless of how extreme an environment your hypothetical life-form can exist in, we do know that any possible life must consist of complex molecules and chemical reactions. About all such complex molecules would break down into their constituent components at that temperature and I'm pretty sure that it wouldn't be much cooler at subterranean levels (underground) either. The planet it basically just giant ball of lava/magma.



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22 Oct 2012, 11:49 am

Jono wrote:

Regardless, we have a pretty good understanding of physics and chemistry. The temperature of the planet can be known from it's proximity to the star. Notice that I did mention extremophiles in my last post? Regardless of how extreme an environment your hypothetical life-form can exist in, we do know that any possible life must consist of complex molecules and chemical reactions. About all such complex molecules would break down into their constituent components at that temperature and I'm pretty sure that it wouldn't be much cooler at subterranean levels (underground) either. The planet it basically just giant ball of lava/magma.


Correct. The sun is approximately a black body and its surface temperature can be calculated from its color (light frequency).

ruveyn



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22 Oct 2012, 12:15 pm

Jono wrote:
DerStadtschutz wrote:
Jono wrote:
I've just read this article about the possible discovery of a planet orbiting Alpha Centauri B. It's unfortunately too close to the star to be in the habitable zone, however given that a planet of similar size further away would of had too small of an effect on the star to be detected by the same method, there could be other planets in the Alpha Centauri system as well. Since the Alpha Centauri system is a triple star system, I guess you could think that this planet has three suns. Although technically, Alpha Centauri B is the sun because that's the one it's orbiting. Here's the news article:

http://www.nytimes.com/2012/10/17/science/space/new-planet-found-in-alpha-centauri.html?_r=1&


Quick question... How do we know it's too close to be habitable? Like... are you aware of the fact that certain fungal spores are capable of surviving the vacuum of space? We assume that all life MUST be like life on earth, which isn't surprising, as it's the only life we know for sure exists, but at the same time, we need to understand that if there was ever life on mars, it would have adapted or just been suited for the conditions on mars. Just because no earth creatures could live on a planet doesn't mean it can't possibly be inhabitable. It just means it can't be inhabited by earth-born creatures.


When we talk about the the habitable zone, we're mostly talking about possibly habitable for life as we know it. The habitable zone is taken to be the region of a solar system where there could be liquid running water on the planet's surface, not too hot or too cold.

Incidentally, we already know about life that can exist in extreme conditions, the so-called extremophiles. However, it's hard to imagine that even they (or organisms similar to them) could survive at the temperatures that the surface of Alpha Centauri Bb is supposed to be. I don't think that the complex chemical reactions necessary for any form of life would be possible at those temperatures.


No extremophiles can live on a glowing sphere with an intense radiation and no atmosphere. Overall, the conditions for live are still very strict, even when extremophiles are taken into account.

Even hibernating tardigrades can't handle radiation that intense and the highest temperature where the most badass extremophiles survive for an extended period of time is 113 degrees celcius.



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22 Oct 2012, 2:01 pm

Face it; there's no life on Hell.


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22 Oct 2012, 2:04 pm

Fnord wrote:
Face it; there's no life on Hell.


lol, I like the way you put that...

Okay, well it appears as though the rest of you have a much better understanding than I on this subject.



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23 Oct 2012, 12:18 pm

The "burning thing" is a K-class orange dwarf star, slightly (but not that much) cooler than the Sun. The planet is orbiting closer to its parent star than Mercury does to the Sun, thus gathering that heat energy, and having its atmosphere stripped away by the solar wind. Further, for part of the - well, "year", for lack of a better term - Alpha Centauri B passes within about 11 AU of Alpha Centauri A, which is a G-class star similar to our Sun, thus adding that much more radiation.

Sorry, what makes Alpha Centauri Bb interesting is that it's the nearest exoplanet thus far discovered, and opens the possibility that their might be a more, well, useful planet orbiting either farther from Alpha Centauri B, or maybe around Alpha Centauri A. (Proxima Centauri is out of consideration because it's a red dwarf, and probably wouldn't put out enough energy for us to be comfortable. There's still an outside chance that it could host a planet capable of supporting life - after all, there might even be microbes on Saturn's moon Titan - but there certainly wouldn't be any planets there we'd like.)


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23 Oct 2012, 4:14 pm

DeaconBlues wrote:
Sorry, what makes Alpha Centauri Bb interesting is that it's the nearest exoplanet thus far discovered, and opens the possibility that their might be a more, well, useful planet orbiting either farther from Alpha Centauri B, or maybe around Alpha Centauri A. (Proxima Centauri is out of consideration because it's a red dwarf, and probably wouldn't put out enough energy for us to be comfortable. There's still an outside chance that it could host a planet capable of supporting life - after all, there might even be microbes on Saturn's moon Titan - but there certainly wouldn't be any planets there we'd like.)


Red dwarfs have a habitable zone closer to the star than yellow dwarf like our sun. Yes, I'm aware of why Alpha Centauri Bb is interesting, that's why I posted this thread. :)