New habitable planet discovered ?

[CraigS]

Interesting discussion … I'll be frank in saying that I'm not sure about it all myself ..

I mean, the Earth will get eaten up by the Sun (or collision with Andromeda, etc), so we have to find ways of leaving the place, eventually. So, we have to fund that exercise. Otherwise, following the "do nothing/don't spend" path logically results in us never escaping !

However, when you look at the unbelievable diversity of environments within our own Solar System planets/moons, it seems to me that the chances of finding another "goldilocks zone" are very slight. (Ie: extrapolating from our own earth-bound perspective, that is).

This then, is counter to the cosmological principal. So, how can one make the quantum leap from our own Solar System observations/empircial evidence to the guiding Cosmological Principle without a little 'faith' ?

Now there's a real question for a Cosmologist/Astro Physicist!!


Cheers
PS: The 'zone' I'm referring to includes the variables needed to support life .. not just the locale.

[renormalised (Carl)]

Originally Posted by higginsdj

What 'fair chance'. All things being equal it is a remote possibility at best. What state is the planet in? Primordial and not a chnace of habitability. A dead rock and no magnetic field and the solar wind will have removed all trace of atmosphere. If it does have an atmosphere, of what does it comprise? What is the melaticity of the system? Did the inner solar system go through the same bombardment process as our own, the primary theory whereby habitable making material was delivered to our planet... Does the system have giant planets protecting the inner solar system?

As I said, what are you calling a 'fair chance'? Yes there is a possibility, but to lead the story saying a habitable planet has been found.....

Cheers

It's said "a probability of it being habitable"....not that it was.

It's in the right spot w.r.t. its orbit, so it has that potential.

You're being to narrow minded in your expectations of the system's characteristics. Some of your above assumptions are not necessarily correct. Case in point, Venus. No magnetic field, plenty of atmosphere despite the solar wind. Even in our own solar system, what we believe happened might not necessarily be the case. Giant planets aren't necessarily guardians of the inner solar system of any star. There are many instances where they do more harm than good, and they don't even have to migrate too far inwards to do damage. It was the jostling between Jupiter and Saturn which created the Late Heavy Bombardment and even now, they may not necessarily protect us from a strike. You have to be careful with interpreting the theory, because even the people studying it don't know all the answers.

The actual science behind the formation and subsequent evolution of planetary systems is far more complicated than you've outlined. I could go into it, as it's my speciality, but there's just not enough time (for my part) or space here to be discussing this topic in depth.

Here's the system at a glance....GL581

[renormalised (Carl)]

Originally Posted by Jay-qu

No need to wait for FTL drives Renormalised, we just need to hit 1g sustained acceleration.

By my calculations, a trip to Gliese 581 (20light years) should take ~5 years (due to relativistic time dilation), though in Earth time it would be more like ~22 years. So a round trip, while only taking 10 years (+time to explore) will return you 44 years after you left..

If you want to be able to explore the close by systems and not have to wait a human lifetime for anything to happen, you're going to have to forget about GR and glorified skyrockets as your means of travel.

Quite frankly, I don't want to have to rely on time dilation as a means of exploring the galaxy. That would be even more so for those left behind.

[renormalised (Carl)]

Originally Posted by CraigS

Interesting discussion … I'll be frank in saying that I'm not sure about it all myself ..

I mean, the Earth will get eaten up by the Sun (or collision with Andromeda, etc), so we have to find ways of leaving the place, eventually. So, we have to fund that exercise. Otherwise, following the "do nothing/don't spend" path logically results in us never escaping !

However, when you look at the unbelievable diversity of environments within our own Solar System planets/moons, it seems to me that the chances of finding another "goldilocks zone" are very slight. (Ie: extrapolating from our own earth-bound perspective, that is).

This then, is counter to the cosmological principal. So, how can one make the quantum leap from our own Solar System observations/empircial evidence to the guiding Cosmological Principle without a little 'faith' ?

Now there's a real question for a Cosmologist/Astro Physicist!!


Cheers

Habitable zones are a feature of all stars, no matter how large they are. The most pressing factor which dominates above all other is just how long that zone remains habitable for and how wide it is. Smaller stars may have very long lifetimes, but there HZ's are smaller than larger stars. So, there's less chance of planets being in them, given all factors. Larger stars have wide HZ's, but they don't last as long. Also, so these zones migrate over time, as stars increases in luminosity as they age. Our own star's HZ is getting larger and further out as it ages....in about 1 billion years, this place will be uninhabitable as the Sun by then will be about 10% brighter than now. We are in the process of migrating out of the HZ of the Sun, due to it shifting outwards.The Earth will lose its water because of this. But even before then, the increasing luminosity will make living here much more difficult. For instance, in about 500 million years, C3 plants (those that photosynthesise 3 carbons to produce energy) will be becoming extinct, as the increasing luminosity of the Sun robs the atmosphere of CO2 (due to increasing oxydation) and the partial pressure drops below sustainable levels for these plants. C4 plants will last another 200-400 million years, but not much longer. After that, when the surface temp reaches an average of 50 degrees and there's no plants left, oxydation will begin to runaway and rob the atmosphere of the gas. With our oceans becoming water vapour, the temp will heat up (GH effect), more oxydation will occur, the water will breakup due to increasing temp and higher UV, but the CO2 in the rocks will by now be getting cooked out. Eventually, the Earth will end up like Venus is now...in about 2-2.5 billion years.

There will be goldilocks zones no matter where we go and they will be as common as the stars themselves, so there's an almost 100% certainty of finding one. Just what's there and what's happening is another question altogether.

[CraigS]

Sorry Carl;

I added the "PS" to my message whilst you were composing. Perhaps poor terminology, but I meant "zone" to include all the variables needed to generate and sustain life … not just the proximity to a Sun.

You have added the further dimension of age, though .. which would seem to make the chances lesser ?

Hmmm …

Cheers

[higginsdj]

Originally Posted by renormalised

The actual science behind the formation and subsequent evolution of planetary systems is far more complicated than you've outlined. I could go into it, as it's my speciality, but there's just not enough time (for my part) or space here to be discussing this topic in depth.

Agreed, and thats my point. Seemingly based on location and size alone, people (those responsible for the article) have made some very big assumptions about habitability (perhaps on purpose to make a headline). There are a thousand more things as critical as these two factors, most of which we do not understand, that also need to be in place for habitability to be a reality.

All I am saying is that there is more probability that it is not habitable than the possibility that it is habitable because of the number of factors we don't know about the system.

Edit: My real gripe is sensationalism in reporting

Cheers

[renormalised (Carl)]

Originally Posted by CraigS

Sorry Carl;

I added the "PS" to my message whilst you were composing. Perhaps poor terminology, but I meant "zone" to include all the variables needed to generate and sustain life … not just the proximity to a Sun.

You have added the further dimension of age, though .. which would seem to make the chances lesser ?

Hmmm …

Cheers

Actually, age increases the chances...the longer the zone lasts for, the greater the chance of life sustaining conditions developing. You just need a planet present that has developed in the right manner. But we haven't yet even considered extreme cases of life and there are plenty of example even on this planet.

[renormalised (Carl)]

Originally Posted by higginsdj

Agreed, and thats my point. Seemingly based on location and size alone, people (those responsible for the article) have made some very big assumptions about habitability (perhaps on purpose to make a headline). There are a thousand more things as critical as these two factors, most of which we do not understand, that also need to be in place for habitability to be a reality.

All I am saying is that there is more probability that it is not habitable than the possibility that it is habitable because of the number of factors we don't know about the system.

Cheers

And that's precisely why we need to directly observe this planet. Pity we can't go there at present. That'd solve the question once and for all

Got any crazy ideas we can throw a few billion dollars at??!!

[CraigS]

In isolation, I tend to agree with David.

But when you consider the scale of the Universe, the small probability may be offset by the vast numbers of stars/planetary bodies.

However, perhaps life did occur … once …

Cheers

[higginsdj]

We need a large space based interferometer....

[renormalised (Carl)]

Originally Posted by higginsdj

We need a large space based interferometer....

A couple of billion should get us a decent sized one

[higginsdj]

Originally Posted by CraigS

In isolation, I tend to agree with David.

But when you consider the scale of the Universe, the small probability may be offset by the vast numbers of stars/planetary bodies.

However, perhaps life did occur … once …

Cheers

Yes, but of the billions of star systems with planets in the habitable zone, whats the chance that the first one we come across will be habitable? Beginners luck

[CraigS]

Originally Posted by higginsdj

Yes, but of the billions of star systems with planets in the habitable zone, whats the chance that the first one we come across will be habitable? Beginners luck

Probability = 1 …
… Planet = Earth

Cheers

[renormalised (Carl)]

Originally Posted by CraigS

In isolation, I tend to agree with David.

But when you consider the scale of the Universe, the small probability may be offset by the vast numbers of stars/planetary bodies.

However, perhaps life did occur … once …

Cheers

That's just it, nothing is or can be taken in isolation. Even if only 1/1000 stars had a planet orbiting in the habitable zone and 1/1000 of them were habitable, that would leave a very large number of habitable planets left to look at. That's just in this galaxy, alone.

[CraigS]

Originally Posted by renormalised

That's just it, nothing is or can be taken in isolation. Even if only 1/1000 stars had a planet orbiting in the habitable zone and 1/1000 of them were habitable, that would leave a very large number of habitable planets left to look at. That's just in this galaxy, alone.

Probability = 1
Planet = Earth

[higginsdj]

Originally Posted by CraigS

Probability = 1 …
… Planet = Earth

Cheers

Hmmmm, but would there be any habitable planets if we weren't here?

[renormalised (Carl)]

Originally Posted by higginsdj

Yes, but of the billions of star systems with planets in the habitable zone, whats the chance that the first one we come across will be habitable? Beginners luck

Not necessarily. If there are billions of them, even if 1/1000 of those is habitable, given the distribution of those planets about the galaxy being random, the chances of one being close by are actually very good.

[higginsdj]

Yes, but you are stating the odds 'favourably'. What if there were only 1/billion, then the odds are not so favourable! The 'odds' don't actually tell us much with such an empty pool to work from so to speak. ie we might be odds on to see one, but it may take 1000 goes before we do.

[renormalised (Carl)]

Originally Posted by higginsdj

Hmmmm, but would there be any habitable planets if we weren't here?

Strong Anthropic Principle...the fact that we are here means there must be habitable planets, otherwise it would be a moot point. If we don't exist, neither do they.

Weak Anthropic Principle...the chances of a planet being habitable isn't necessarily a condition of our presence, but their observation by us means that fact is known and therefore they must exist, for we inhabit one of them.

Take you pick

[CraigS]

I reckon to assume life anywhere else requires a leap of faith.

Here's a reasonably reputable article written by an (East Anglia) Professor.

Worth a quick a read .. it's not too long ..

Cheers