Alpha Centauri has a planet

[Winner]

Pseudo-habitable, minimum. The original Chiron did have a toxic atmosphere.

Spoiler :

Fairly sure Cameron stole it from the game when he made Avatar.

Not really toxic per se, just too much nitrogen and nitrogen compounds. Actually, the game made me interested in partial pressure of atmospheric gases and all that related stuff, which I then used it in my own world building projects

Chiron was well thought over. Too bad the backstory didn't feature a little more strongly in the game.

 

[classical_hero]

Is that really a surprise given that we have only partially explored one solar system so far? Finding a planet orbiting the nearest neighboring star which could likely support life just increased those odds substantially.

Mars and Venus are in the "habitable" zone and yet we know that both planets are far too toxic for life to have lived on them.

 

[El_Machinae]

And the gas giants are well outside the habitable zone, but there's decent suspicion that their ice moons might contain the proper conditions for life.

Our galaxy is a cornucopia full of potentials.

Old school CFCers have seen me say this before: proactively help us become a space borne species, please!

 

[Borachio]

And this is important because of what?

How about we learn to properly manage this planet before we take to the skies space and muck up anymore?

It depends where your priorities lie, I suppose. Starving millions billions or shiny bits of space junk.

Walk before you run, is the old adage.

 

[Winner]

And this is important because of what?

How about we learn to properly manage this planet before we take to the skies space and muck up anymore?

It depends where your priorities lie, I suppose. Starving millions billions or shiny bits of space junk.

Walk before you run, is the old adage.

Run instead of walking, if you want to have any hope of leaving a burning building alive

Besides ten million practical benefits space exploration provides to humanity that actually help in developing the kind of sustainable economy you're speaking of, it's the ultimate insurance policy that human kind won't go extinct due to one of the hundreds of possible causes.

 

[hobbsyoyo]

Mars and Venus are in the "habitable" zone and yet we know that both planets are far too toxic for life to have lived on them.

Mars and Venus are outside of the habitable zone. Earth life could not exist there. Also, toxic =/= uninhabitable. There are plenty of toxic environments that support life.

In Mars's case the main issues are that the atmosphere is too thin for liquid water and it recieves too much solar radiation (no protective magnetic field) to sustain an appreciable atmosphere.

For Venus it is too hot and high pressured for most Earth life.

Both planets lack liquid water.

However, there may well be exotic life on either planet we haven't found yet, particularly in Venus' case.

Also, how has this thread avoided a merge?

 

[Winner]

Veeery close to the star.

Mars and Venus are outside of the habitable zone. Earth life could not exist there. Also, toxic =/= uninhabitable. There are plenty of toxic environments that support life.

Hm, that depends on the definition. Venus is probably too close to the Sun; Mars, however, could have supported an Earth-like biosphere if it was slightly bigger. I once made a little sci-fi exercise on another forum where I worked with a simple scenario: what if Venus and Mars had formed in reversed orbits? I ended up with one airless, sun blasted Luna-like planet (Mars is Venus' orbit) and one Earth-twin (Venus in Mars' orbit). I must return to it one day

 

[hobbsyoyo]

Venus doesn't have a global magnetic field. It's atmosphere would've been stripped as without the runaway greenhouse effect that comes with it's orbit, it wouldn't have had as thick an atmosphere as it does now. Plus, it's doubtful that life could've been sustained long term without plate tectonics recycling necessary elemental resources.

 

[Crezth]

Does greenhouse effect keep the atmosphere in? I think you're putting the cart before the horse here.

 

[Winner]

Venus doesn't have a global magnetic field. It's atmosphere would've been stripped as without the runaway greenhouse effect that comes with it's orbit, it wouldn't have had as thick an atmosphere as it does now. Plus, it's doubtful that life could've been sustained long term without plate tectonics recycling necessary elemental resources.

I posited that the lack of magnetic field is a result of Venus' weird rotation period, which is a result of its dense atmosphere. The lack of plate tectonics is likely a result of the lack of water cover (water acts as lubricant). Since neither would be the case if Venus formed in Mars' orbit, I did away with these inconveniences

Does greenhouse effect keep the atmosphere in? I think you're putting the cart before the horse here.

It doesn't. Venus' dense atmosphere is a result of its oceans evaporating, being broken down to oxygen and hydrogen by UV radiation, and oxygen then reacting with carbon and sulphur. Venus' (presumed) volcanism then replenishes the atmosphere.

 

[hobbsyoyo]

Does greenhouse effect keep the atmosphere in? I think you're putting the cart before the horse here.

The greenhouse effect ensures the atmosphere that is lost to radiation is replaced by boiled off crust and by volcanism. I'm not sure Venus ever had oceans as there is little steam vapor in the atmosphere. Though it could've been split into oxygen and hydrogen that was lost to space as happened to Mars. There may also be a component of the Venusian atmosphere that effectively shields the rest from radiation similar to ozone, so there may have been a way for Venus to keep it's atmosophere in Mars' orbit. idk

@Winner - is water a prerequisite for plate tectonics? And if it is there would still have to be proof that Venus had oceans in the past for the whole scenario to work IMO.

 

[Valka D'Ur]

Mars and Venus are in the "habitable" zone and yet we know that both planets are far too toxic for life to have lived on them.

They're not in the habitable zone for humans. But Mars did have liquid water on its surface a very long time ago, and who knows what remnants of lifeforms may be waiting to be found?

Venus... wow. Venus is one strange planet - it scares me into nightmares every time I re-read Ben Bova's novel Venus,

Spoiler :

about the lifeforms in the atmosphere.

If there is life on Venus (or the remnants of life), it would be of the extremophile sort that thinks sulphur is really yummy stuff and insanely high pressure and temperatures are "just right."

 

[hobbsyoyo]

Yeah that novel is great - so is the whole grand tour series.

I am optimistic there is life on Venus and Europa. Little more pessimistic on Martian life though.

 

[strijder20]

I am optimistic there is life on Venus and Europa. Little more pessimistic on Martian life though.

I'm pretty sure we've already proved there is no Martian life, or it's living somewhere beneath the surface.

 

[hobbsyoyo]

We don't know enough or explored enough to prove anything though except there isn't plants and animals as we know them on the surface.

 

[Borachio]

Run instead of walking, if you want to have any hope of leaving a burning building alive

Besides ten million practical benefits space exploration provides to humanity that actually help in developing the kind of sustainable economy you're speaking of, it's the ultimate insurance policy that human kind won't go extinct due to one of the hundreds of possible causes.

You have a point with the burning building. Except, what if your efforts to escape the building are actually setting it alight in the first place?

And indeed, the long term aim could well have to be escaping the planet. Though I would personally be happier as seeing this in terms of 10,000 years rather than 100-200.

It's just that if you can't be bothered to feed the people right here right now, and you go on polluting the planet to bits instead, how to you expect me to be enthusiastic about space exploration?

 

[Formaldehyde]

Mars and Venus are in the "habitable" zone and yet we know that both planets are far too toxic for life to have lived on them.

Life may very well have existed on Mars at some stage, and both may even have organisms that are far different than what we consider life to be, as others have pointed out. We simply don't know for any certainty at this stage.

Do you feel threatened by the notion that life may quite likely exist in some form on some other planet?

 

[hobbsyoyo]

You have a point with the burning building. Except, what if your efforts to escape the building are actually setting it alight in the first place?

And indeed, the long term aim could well have to be escaping the planet. Though I would personally be happier as seeing this in terms of 10,000 years rather than 100-200.

It's just that if you can't be bothered to feed the people right here right now, and you go on polluting the planet to bits instead, how to you expect me to be enthusiastic about space exploration?

Many of the technologies and techniques that will further space exploration will help 'save the earth' (however you define that). The two goals aren't mutually exclusive - in fact they reinforce each other.

@winner

The fact that Venus lacks a moon further complicates your hypothesis. The fact that Mars currently has the same axial tilt of Earth is a coincidence. In the blink of a geological eye the planet can and does shift 180 degrees on it's axis. Presumably Venus would do the same free of tidal locking forces from the Sun and with a thinner atmosphere that would come with a swapped orbit. This would make it very difficult for life to adapt or advance very far with such radically shifting climate.

 

[hobbsyoyo]

Life may very well have existed on Mars at some stage, and both may even have organisms that are far different than what we consider life to be, as others have pointed out. We simply don't know for any certainty at this stage.

Do you feel threatened by the notion that life may quite likely exist in some form on some other planet?

If I were a christian, I would feel threatened by e.t. intelligent life if it didn't believe in Jesus.

I wonder what christians think about this conundrum.

 

[warpus]

I think the problem for some may be that Genesis only talks about life being created on 1 planet.

Then again, different people will find objections for different reasons.