[opportunity (OP)]

I'm thinking its more logical to colonise Venus than Mars.....

Hear me out.

Land a craft especially built to contract that takes use of the pressure, that slowly compresses to create all the necessary energy needed to support life.....that uses the compression energy of Venus' atmosphere.

Any ideas?

Do that long enough, the compression goes, time to leave the capsule. Wouldn't try that 50,000 leagues under the sea of course......nothing to look forward to.

[alancalverd]

Surface temperature of Venus is 460°C, Mars around -40°C. No problem keeping warm (lots of people live in the Arctic and we regularly fly at -40 to -60) major problem keeping cool.

The surface of Mars is well mapped, pretty much like a terrestrial cold desert. Venus may not even be solid as far as we know.

[opportunity (OP)]

Surface temperature of Venus is 460°C, Mars around -40°C. No problem keeping warm (lots of people live in the Arctic and we regularly fly at -40 to -60) major problem keeping cool.

The surface of Mars is well mapped, pretty much like a terrestrial cold desert. Venus may not even be solid as far as we know.

You're absolutely right......what's the point of going to a pressure cooker planet versus something that is stale?

[Bored chemist]

Surface pressure on Venus is about 90 Bar.
That's equivalent to about 9 MJ per cubic metre of "crushed" vessel.
To put that in context, the food I eat each day gives me about the same energy.

Good luck running the air con with so little energy.

[chiralSPO]

Venus may not even be solid as far as we know.

Umm... Both the Soviets and Americans landed probes on the surface. It's solid. We also have radar maps of the whole surface https://sos.noaa.gov/datasets/venus-topography/

photos from landers:
ftp://public.sos.noaa.gov/astronomy/venus/landings/venera13.jpg
ftp://public.sos.noaa.gov/astronomy/venus/landings/venera14.jpg

I have heard that it might make more sense to colonize the upper atmosphere of Venus, where the temperatures and pressures are more manageable and there is more solar power available than one could shake a stick at (it would still need to be entirely enclosed, as the atmosphere is quite toxic).

[opportunity (OP)]

Exactly.

Design a craft that compacts under the pressure and coverts that compaction into life sustaining energy......slowly...

Am I wrong in thinking Mars is a far worse petri dish of research potential?

[syhprum]

I am horrified by the thought that humans might be landed on Mars this planet is the best example of virgin biology that is within easy reach, if humans land on it will be very quickly colonised by Earth type bacteria .
we are rapidly lousing up one planet do we need to spoil a second one? 

[Kryptid]

Design a craft that compacts under the pressure and coverts that compaction into life sustaining energy......slowly...

Bored Chemist already addressed that such energy would be pretty small and not very useful. Once your spacecraft finishes contracting under that pressure, then that's it. There's no more energy to be extracted that way.

It would also be significantly more difficult to do a return mission from Venus to Earth than it would be to do one from Mars to Earth, due to the substantially higher gravity and atmospheric density on Venus vs. Mars.

[Ophiolite]

I am horrified by the thought that humans might be landed on Mars this planet is the best example of virgin biology that is within easy reach, if humans land on it will be very quickly colonised by Earth type bacteria .
we are rapidly lousing one planet do we need to spoil a second one? 

We do not even know if it has a biology to be loused up.
If it does, that biology has had three or four billion years to become acclimated to conditions. The poor old terrestrial bacteria might not stand a chance.
If there is an extant biology we don't know that it has sufficient similarity to be in competition.
If it is a concern, it is probably already to late. The sterilisation processes for the spacecraft that have landed there are, I think, acknowledged to be less than 100% effective. There are already terrestrial microbes on Mars.

On the other hand, even with no biosphere, one can make an argument for not corrupting the exisitng environment. Kim Stanley Robinson develops this argument and the one for terraforming the planet, in his excellent Mars trilogy. (Red Mars, Green Mars, Blue Mars)

[opportunity (OP)]

I was throwing the idea out there loosely to get some pro's and con's for exploration on Mars versus Venus for instance. Take Venus, what type of space-ship structure is required to land safely and live in that structure? Understandably heat and pressure would be an issue, yet can that heat and pressure be used extract energy for the space-craft to maintain itself? Furthermore, does Venus have relatively colder regions, polar regions for instance making a mission more possible?

[Bored chemist]

I was throwing the idea out

You should have stopped there.

[Kryptid]

I was throwing the idea out there loosely to get some pro's and con's for exploration on Mars versus Venus for instance.

Our current technology level would probably make Mars the better choice for colonization, but you're right that we shouldn't count Venus out entirely. In terms of human acclimatization, its gravity is much closer to Earth's than that of Mars. Its thick atmosphere is rich in carbon dioxide, nitrogen and sulfur compounds which could prove useful. It also gets much more solar energy than Mars (at least in orbit. I'm not sure how much it gets at the surface).

Take Venus, what type of space-ship structure is required to land safely and live in that structure?

Something very durable and therefore very heavy, which would make it significantly more expensive than a rocket to Mars with a similar mission profile. I think I'd prefer to have a base built deep underground on Venus where it is no doubt much cooler.

Understandably heat and pressure would be an issue, yet can that heat and pressure be used extract energy for the space-craft to maintain itself?

The pressure thing has been addressed, and the high temperature is useless as a power source unless you have a temperature gradient to work with. Wind turbines designed with similar materials to the refractory alloys used in jet engines might prove sufficient to draw power from the slow (yet dense) wind on Venus. A fission reactor could prove sufficient as well (though I'm not sure if mining for fissile material on Venus is feasible. Almost certainly not at the moment. You'd have to get fuel shipped in from Earth or maybe the Moon).

Furthermore, does Venus have relatively colder regions, polar regions for instance making a mission more possible?

The temperature on Venus' surface is much more uniform than on Earth due to the thicker atmosphere distributing heat very well. However, there are certain places that are better than others. Maxwell Montes is a bit cooler than the lower areas of Venus (380 degrees Celsius vs. 462 degrees Celsius) and has a lower pressure (44-45 bars vs. 90-92 bars). Much higher in the atmosphere, the temperature and pressure combinations are actually rather Earth-like. That has led to the idea of having floating cities at these altitudes. Such a thing isn't going to happen for a long time, however.

[alancalverd]

I am tempted to ask why.

Mars is of scientific interest because it may have had recognisable life at some time, or may be ripe for sustaining life in future, so it can give us insights into biogenesis and evolution. We are most unlikely to discover anything on Venus that isn't already known to physics and chemistry.

If the objective is to colonise another planet, again the question why applies: human exploration of Earth has been driven by famine, politics and religion, none of which need to exist in the future, and scientific curiosity. The latter will probably persist for as long as intelligent life can fight off parasites and teenagers with machine guns, but it hasn't led to colonisation in places of scientific curiosity: if anything, we try to keep the poles, mountains, deserts and deep oceans fairly pristine. But if irrationality should win in the long term (and the signs are already present), the whole point of colonisation is to introduce homo sapiens and all its accompaniments like agriculture, pathogens and general pollution.

[Bored chemist]

where it is no doubt much cooler.

Why?

[Kryptid]

where it is no doubt much cooler.

Why?

I was going by analogy that Earth is cooler underground than on its surface (until you dig deep enough that geothermal effects become important). Though now you have brought it up, perhaps my reasoning was incorrect. I imagine heat conducted from the hot atmosphere would keep the Venusian subsurface pretty hot as well.

[evan_au]

more solar energy than Mars (at least in orbit. I'm not sure how much it gets at the surface)

I understand that almost no visible light makes it through that thick soup of an atmosphere - it is almost all reflected (which is why venus is so bright in the sky).

It is a very intense infra-red environment, at high temperatures, which makes solar cells very inefficient anyway.

temperature gradient ...A fission reactor

A fission reactor would be quite inefficient, as there are no oceans of cool water (with water's high heat capacity).

Your "cold" sink is the atmosphere, at around 400C. That greatly reduces the efficiency of the reactor, and places the components under much greater thermal stress.

Quote
Take Venus, what type of space-ship structure is required to land safely and live in that structure?
Kryptid: Something very durable and therefore very heavy,

Bigelow has an inflatable module attached to the International Space station, withstanding the vacuum of space, extremes of day/night temperature, and micrometeorites. The internal atmospheric pressure inflates it. This structure is very light compared to its volume.

Mars has almost a vacuum on the surface (1% of Earth-normal), but the thin atmosphere provides protection from the micrometeorites, and reduces the extremes of day/night temperature variation. This would be a great location for a Bigelow module.

Anything on Venus would need to be built like a deep-ocean submarine, to withstand the severe external crushing forces.

I suggest that we first send rovers, to Earth's Moon (done) and Mars (done), then other parts of the Solar system.
- To send a manned short-term visit, I suggest Earth's Moon (already done), one of Mars' (tiny) moons, and then Mars itself.
- If we were going to set up a more permanent manned base somewhere else (beyond LEO), I vote for the Moon first  (to test  procedures) and then Mars.

I suggest we get a long-term working rover on the surface of Venus long before we try sending humans there. So far, landers have survived only a short time on Venus - and they didn't even try moving anywhere!

[Kryptid]

A fission reactor would be quite inefficient, as there are no oceans of cool water (with water's high heat capacity).

Your "cold" sink is the atmosphere, at around 400C. That greatly reduces the efficiency of the reactor, and places the components under much greater thermal stress.

Thanks for the information. I had not even considered it.

[opportunity (OP)]

I don't want to sound too extreme, but is there a case for colonizing Venus with microbes......send off lots of earth based microbial activity to do it's work.....especially given it's not possible for us as humans to colonise......can we send in microbes to develop? Or is that unethical? Is it more ethical for us to colonise Mars with humans that stand a less chance than microbes on Venus? Or better still, is it more practical? Humans on Venus doesn't seem practical, yet why should that discount other forms of life on Earth?

What would we do if we had the ability to fly light years and find a planet we could see as a pressure cooker of potential life and we had a handful of microbes, buckets of it, to aim to evolutionise (if there is a word) a planet? Or, we can't do that in our own backyard? It's unethical?

Do we have lifeforms on this planet that like volcanic activity, can sustain it, thrive in it, our own little space ships of colonisation for instance?

If there's no life on Mars, and the place is fairly inert, well, very, Venus seems more logical to land what we can to colonise.

The aim of mining the Moon? That's ethical? And putting microbes on Venus is unethical?

[Colin2B]

Do we have lifeforms on this planet that like volcanic activity, can sustain it, thrive in it, our own little space ships of colonisation for instance?

Ethics aside, yes plenty of candidates from undersea volcanic fissures known as black smokers.
https://www.sciencedaily.com/releases/2012/08/120806151252.htm

Problems might be their food source and waste -  inhale hydrogen and carbon dioxide to produce methane as waste, not exactly terraforming unless the methane is easily convertible. I’m fairly sure others I’ve come across have different feeding patterns.

[Kryptid]

I don't want to sound too extreme, but is there a case for colonizing Venus with microbes......send off lots of earth based microbial activity to do it's work.....especially given it's not possible for us as humans to colonise......can we send in microbes to develop? Or is that unethical? Is it more ethical for us to colonise Mars with humans that stand a less chance than microbes on Venus? Or better still, is it more practical? Humans on Venus doesn't seem practical, yet why should that discount other forms of life on Earth?

What would we do if we had the ability to fly light years and find a planet we could see as a pressure cooker of potential life and we had a handful of microbes, buckets of it, to aim to evolutionise (if there is a word) a planet? Or, we can't do that in our own backyard? It's unethical?

Do we have lifeforms on this planet that like volcanic activity, can sustain it, thrive in it, our own little space ships of colonisation for instance?

If there's no life on Mars, and the place is fairly inert, well, very, Venus seems more logical to land what we can to colonise.

The aim of mining the Moon? That's ethical? And putting microbes on Venus is unethical?

Any microbe would be annihilated by Venus' surface conditions. It's just too hot there. They would be able to tolerate temperatures higher in the atmosphere, but the lack of water would be a problem for any life form we know of.