First habitable planet....

https://arxiv.org/ftp/arxiv/papers/1608/1608.00706.pdf

...momentum is building to explore Venus, in part because scientists say it could hold the secret to understanding what makes a planet habitable. Once Earth’s twin, today Venus is a hellish abode where surface temperatures reach more than 400 °C, atmospheric pressures slam down with enough force to crush heavy machinery and clouds of sulfuric acid blow through the sky. If researchers could decipher why conditions on Venus turned so deadly, that would help them to assess whether life might exist on some of the thousand-plus rocky worlds that astronomers are discovering throughout the Galaxy.

I can't wait to sign up for the manned space mission. 400C and sulfuric acid showers sounds bad. Given the current conditions on Venus, are there life forms that exist on Earth that would survive on Venus?

https://www.nature.com/articles/d41586-019-01730-5

@wildgrass
https://www.skyandtelescope.com/astronomy-news/why-is-earth-magnetized-and-venus-not-magnetized/

@metal-brain said
@wildgrass
https://www.skyandtelescope.com/astronomy-news/why-is-earth-magnetized-and-venus-not-magnetized/

You posted this because...?

@wildgrass said
You posted this because...?

One thing is without a planetary wide magnetic field, there is no protection from solar winds which can bleed off a planetary atmosphere and rather quickly from a cosmic time scale perspective, a few million years or so.
That seems to be one reason Mars has not much atmosphere or open water now.

@sonhouse said
One thing is without a planetary wide magnetic field, there is no protection from solar winds which can bleed off a planetary atmosphere and rather quickly from a cosmic time scale perspective, a few million years or so.
That seems to be one reason Mars has not much atmosphere or open water now.

But Venus has an atmosphere.

@wildgrass said
But Venus has an atmosphere.

AFAIK it does not have a field. But the atmosphere is more like the inside of a full N2 bottle so there would be a lot of atmosphere to remove.
My question and I imagine a lot of other people have the same question, how in the heck did it get an atmosphere that thick?
And how long has it had that much of an atmosphere?
There are some indications the upper atmosphere may have active life forms, maybe bacteria, doing weird things to the UV spectrum.
Here is one link about life at Venus:

http://time.com/5224561/venus-life-atmosphere-bacteria/

@sonhouse said
AFAIK it does not have a field. But the atmosphere is more like the inside of a full N2 bottle so there would be a lot of atmosphere to remove.
My question and I imagine a lot of other people have the same question, how in the heck did it get an atmosphere that thick?
And how long has it had that much of an atmosphere?
There are some indications the upper atmosphere may ...[text shortened]... .
Here is one link about life at Venus:

http://time.com/5224561/venus-life-atmosphere-bacteria/

I guess we'll find out the active life forms question in around 10 years.

Very possible that the surface of Venus was earth-like and habitable for a very long time. Like a few billion years. Then the core stopped spinning and the atmosphere condensed because the low density stuff was carried away by solar winds.

@wildgrass said
I guess we'll find out the active life forms question in around 10 years.

Very possible that the surface of Venus was earth-like and habitable for a very long time. Like a few billion years. Then the core stopped spinning and the atmosphere condensed because the low density stuff was carried away by solar winds.

The Wikipedia article on Venus is interesting about this. I'm off my field here, but I'd hazard a guess that the core composition of Earth is special in that it required the collision that produced the Moon - or the presence of the Moon to keep the dynamo effect running.

The lack of an intrinsic magnetic field at Venus was surprising, given that it is similar to Earth in size and was expected also to contain a dynamo at its core. A dynamo requires three things: a conducting liquid, rotation, and convection. The core is thought to be electrically conductive and, although its rotation is often thought to be too slow, simulations show it is adequate to produce a dynamo. This implies that the dynamo is missing because of a lack of convection in Venus's core. On Earth, convection occurs in the liquid outer layer of the core because the bottom of the liquid layer is much hotter than the top. On Venus, a global resurfacing event may have shut down plate tectonics and led to a reduced heat flux through the crust. This caused the mantle temperature to increase, thereby reducing the heat flux out of the core. As a result, no internal geodynamo is available to drive a magnetic field. Instead, the heat from the core is being used to reheat the crust.

One possibility is that Venus has no solid inner core, or that its core is not cooling, so that the entire liquid part of the core is at approximately the same temperature. Another possibility is that its core has already completely solidified. The state of the core is highly dependent on the concentration of sulfur, which is unknown at present.

https://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core

@deepthought said
The Wikipedia article on Venus is interesting about this. I'm off my field here, but I'd hazard a guess that the core composition of Earth is special in that it required the collision that produced the Moon - or the presence of the Moon to keep the dynamo effect running.

The lack of an intrinsic magnetic field at Venus was surprising, given that it is similar to Ea ...[text shortened]... r, which is unknown at present.

https://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core

There was an article in Scientific American a while back saying whatever planet whacked Earth, creating the moon, also had enough iron to sink to the center of Earth and therefore make the core quite a bit larger. That may explain why Earth still has a significant field.

@deepthought said
The Wikipedia article on Venus is interesting about this. I'm off my field here, but I'd hazard a guess that the core composition of Earth is special in that it required the collision that produced the Moon - or the presence of the Moon to keep the dynamo effect running.

The lack of an intrinsic magnetic field at Venus was surprising, given that it is similar to Ea ...[text shortened]... r, which is unknown at present.

https://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core

Instead of launching cars into space, Elon should be aiming pods full of extremophiles at Venus.

@wildgrass said
Instead of launching cars into space, Elon should be aiming pods full of extremophiles at Venus.

I'd vote for Trump to be in the first shipment.....

@sonhouse said
I'd vote for Trump to be in the first shipment.....

I'm talking about organisms that could actually survive outside their home ecosystem. I think that guy has bone spurs or something, probably not the best candidate.

I'd go though. Put me in a version of the ISS that orbits Venus instead of Earth. Probably a Tesla wouldn't survive the surface, but there are designs that should work. We'll drop down some probes, engineer some oxygen-producing bugs that could terraform the atmosphere from the top down. Then we'd just start over. No MAGA no problem.

I don't see how this doesn't work.

@wildgrass said
I'm talking about organisms that could actually survive outside their home ecosystem. I think that guy has bone spurs or something, probably not the best candidate.

I'd go though. Put me in a version of the ISS that orbits Venus instead of Earth. Probably a Tesla wouldn't survive the surface, but there are designs that should work. We'll drop down some probes, engineer s ...[text shortened]... m the top down. Then we'd just start over. No MAGA no problem.

I don't see how this doesn't work.

It might only take 5000 years too! But the part where the pressure is about 1500 PSI of a sulfuric acid atmosphere gives one pause, and the 400 C doesn't help either, and the lack of mag field is a hindrance.
I think it would be easier to do Mars. At least there we deal with very low atmosphere so going from zero to 10 or 15 PSI would be a lot easier than going from a 400 C 1500 PSI acidic atmosphere. Plus they just found a huge fund of water ice on mars, enough to give a few feet depth on the whole planet from that one source so all in all Mars is a much better prospect. We even have helicopter designs that we know will work on Mars. It's a matter of designing one that works at 100,000 feet on Earth but helped by the near half gravity field.

@sonhouse said
It might only take 5000 years too! But the part where the pressure is about 1500 PSI of a sulfuric acid atmosphere gives one pause, and the 400 C doesn't help either, and the lack of mag field is a hindrance.
I think it would be easier to do Mars. At least there we deal with very low atmosphere so going from zero to 10 or 15 PSI would be a lot easier than going from a 400 ...[text shortened]... tter of designing one that works at 100,000 feet on Earth but helped by the near half gravity field.

5,000 years seems about right, timing wise. I think Venus gets a leg up because it has Earth-like gravity and is closer, making it easier.

I think it'll be very interesting to learn about the geological history of Venus, and specific chemical compositions, in the coming decade.

@wildgrass said
5,000 years seems about right, timing wise. I think Venus gets a leg up because it has Earth-like gravity and is closer, making it easier.

I think it'll be very interesting to learn about the geological history of Venus, and specific chemical compositions, in the coming decade.

Sure but it will be a lot easier to settle Mars than it ever will be to do Venus. We might be able to live in satellites above the surface and benefit from the greater solar energy available there but that is about it. We couldn't very easily get minerals and metals from the surface of Venus, not when you have to endure 1000 degree F and 1500 PSI acidic atmosphere.
The Soviets managed to land a probe on Venus and did some tricky engineering using I think, liquid N2 squirting around pipes to extend the life of the probe but it still pooped out in less than an hour but managed to get some photo's showing it really is like hell.

I don't see any way we could get rid of that much atmosphere and heat. Maybe a world wide solar shield that would eventually cool it down but you would then be left with still a very acidic and high pressure atmosphere, like diving into a hydrothermal vent on Earth but one thousands of miles wide.

Also, work is proceeding on fusion propulsion that can cut the time going to Mars or Venus by 5 to 1, right now to Mars, around 500 days and this new fusion rocket, less than 100 days. That is very important because we could not survive a solar corona blast that shoots out of the sun with some regularity. If we go 5 times faster, the odds of surviving such a trip goes up exponentially.

I think fusion rocket tech will eventually get that down to a trip of a week. If we have a rocket capable of doing 1 g for long periods of time, Acel to halfway and decel to the target, we get going REALLY fast.

1 g for 1 year = the speed of light.

So 1 g for 1 week = 1/50th of c.

c= 300,000 odd km/sec. so 1/50 c is about 6000 km/second.
THAT is fast!

Of course the first fusion rockets would crank out maybe 1/20th of a g as just a guess but that would be just the starting gate of that technology.
That would be a acceleration of about 1/2 meter/sec^2 so in 10,000 seconds you would be going 5 Km/second, so in one day you would be going about 50 Km/second, so you can see even with that weak an acel, you would soon be going a lot faster than a chemical rocket.
The neat thing about long term 1 g acell is going to Pluto would also take only a week or two and would also make for the possibility of local interstellar trips,
8000 hours at 1 g is damn near the speed of light so if you can avoid the pesky problem of colliding with a spec of dust that would be more like a hit with a semi truck, you get to Alpha Centauri in maybe 5 or 10 years, instead of 50,000 years with today's tech.

And the closer you get to c , the slower the clocks run on the ship so ship time might only be a month or so to get to some star say 100 ly away.
Of course you go there, spend ten years there, go back to Earth and 210 years have gone by on Earth while about ten years goes by for the explorers but if the tech is available for that kind of journey there will be people who will volunteer.
Still pie in the sky for now but the fusion rocket may be a real deal in another 10 years.
There are sci fi stories showing the development of actual interstellar civilizations built up using that kind of tech and ways of doing business even though hundreds of years go by for the journey.

https://www.space.com/37146-nuclear-fusion-rockets-interstellar-spaceflight.html